Rising atmospheric carbon dioxide might cause so much heating that some countries will respond by releasing sulfate aerosols to reflect sunlight and cool the planet. If that happens the question arises: Will the net effect of less sunlight (which would reduce energy flowing to plants) be outweighed by the plant-boosting effects of lower temperatures and higher CO2? Some climate scientists did modeling that suggests globally crop yields would rise overall but fall in some areas.
Although scientists know that climate change in recent decades has negatively impacted crop yields in many regions, the study by Pongratz and colleagues is the first to examine the potential effect of geoengineering on food security. Pongratz's team, which included Carnegie's Ken Caldeira and Long Cao, as well as Stanford University's David Lobell, used models to assess the impact of sunshade geoengineering on crop yields.
Using two different climate models, they simulated climates with carbon dioxide levels similar to what exists today. A second set of simulations doubled carbon-dioxide levels – levels that could be reached in several decades if current trends in fossil-fuel burning continue unabated. A third set of simulations posited doubled carbon dioxide, but with a layer of sulfate aerosols in the stratosphere deflecting about 2% of incoming sunlight away from the Earth. The simulated climate changes were then applied to crop models that are commonly used to project future yields.
The team found that, in the model, sunshade geoengineering leads to increased crop yields in most regions, both compared with current conditions and with the future projection of doubled carbon dioxide on its own. This is because deflecting sunlight back to space reduces temperatures, but not CO2. "In many regions, future climate change is predicted to put crops under temperature stress, reducing yields. This stress is alleviated by geoengineering," Pongratz said. "At the same time, the beneficial effects that a higher CO2 concentration has on plant productivity remain active."
Of course this work was done with a model that is much simpler than the real planet. Future improvements in model quality could yield different results. Still, an interesting result.
The researchers point out that sulfate aerosols would not reverse the ocean acidification caused by more CO2 dissolving into the oceans. Speaking of ocean acidification, rising atmospheric CO2 will increase the acidification of the oceans so much that the coral reefs would drastically shrink in extent.
"In some regions, the man-made rate of change in ocean acidity since the Industrial Revolution is hundred times greater than the natural rate of change between the Last Glacial Maximum and pre-industrial times," emphasizes Friedrich. "When Earth started to warm 17,000 years ago, terminating the last glacial period, atmospheric CO2 levels rose from 190 parts per million (ppm) to 280 ppm over 6,000 years. Marine ecosystems had ample time to adjust. Now, for a similar rise in CO2 concentration to the present level of 392 ppm, the adjustment time is reduced to only 100 – 200 years."
On a global scale, coral reefs are currently found in places where open-ocean aragonite saturation reaches levels of 3.5 or higher. Such conditions exist today in about 50% of the ocean – mostly in the tropics. By end of the 21st century this fraction is projected to be less than 5%. The Hawaiian Islands, which sit just on the northern edge of the tropics, will be one of the first to feel the impact.
If necessary we could use a variety of climate engineering techniques to prevent the melting of Antarctica and Greenland. But I've yet to come across a proposal for how to prevent a shift in ocean acidity as atmospheric CO2 continues to rise.
Robert K. Kaufmann of Boston University and a few other researchers have proposed a theory to explain why global warming basically stopped for about 10 years: sulfur aerosols emissions from China's big surge in coal burning (doubling from 2003 to 2007!) have canceled out most of the warming effects of higher carbon dioxide. Accidental large-scale climate engineering. What a fascinating experiment. Massive sulfur never would have been politically approved as an intentional intervention for cooling.
Given the widely noted increase in the warming effects of rising greenhouse gas concentrations, it has been unclear why global surface temperatures did not rise between 1998 and 2008. We find that this hiatus in warming coincides with a period of little increase in the sum of anthropogenic and natural forcings. Declining solar insolation as part of a normal eleven-year cycle, and a cyclical change from an El Nino to a La Nina dominate our measure of anthropogenic effects because rapid growth in short-lived sulfur emissions partially offsets rising greenhouse gas concentrations.
CO2's half-life in the atmosphere is decades (centuries?) longer than sulfur's. So these effects of sulfur are short-lived. Worse, attempts to reduce sulfur emissions to cut ground-level pollution can cause a rapid decrease in sulfur aerosol cooling effects.
This idea is at least plausible because sulfur aerosols have a cooling effect. In fact, Nobel Prize winning chemist Paul Crutzen has proposed injecting sulfur into the atmosphere to cool the planet. By using airplanes to inject sulfur aerosols at high altitudes the half-life of sulfur in the atmosphere can be boosted to a year and a half.
There are downsides to this approach to climate engineering. For example, by making more light diffuse sulfur will reduce the output of concentrating solar power by as much as a fifth. But it beats melting all the ice in Greenland.
I realize many are skeptics about the role of CO2 in warming the planet. But if sulfur's role as a cooler is real then China's big burst in dirty coal burning has to have prevented a warmer planet.
Researchers at the U.S. Department of Energy’s Ames Laboratory and the University of Colorado find evidence that wind turbines alter microclimates for farm crops, possibly for the better.
“We’ve finished the first phase of our research, and we’re confident that wind turbines do produce measureable effects on the microclimate near crops,” said Ames Laboratory associate and agricultural meteorology expert Gene Takle. According to Takle, who is also a professor of agricultural meteorology and director of the Climate Science Program at Iowa State University, the slow-moving turbine blades that have become a familiar sight along Midwestern highways, channel air downwards, in effect bathing the crops below via the increased airflow they create.
Wind turbines might reduce temperature extremes and lengthen growing seasons.
For instance, crops warm up when the sun shines on them, and some of that heat is given off to the atmosphere. Extra air turbulence likely speeds up this heat exchange, so crops stay slightly cooler during hot days. On cold nights, turbulence stirs the lower atmosphere and keeps nighttime temperatures around the crops warmer.
“In this case, we anticipate turbines’ effects are good in the spring and fall because they would keep the crop a little warmer and help prevent a frost,” said Takle. “Wind turbines could possibly ward off early fall frosts and extend the growing season.”
Global climate engineering is controversial. Yet microclimate alteration using wind turbines looks like it is not going to generate much if any opposition.
Reflecting sunlight from the Earth by geoengineering would undoubtedly cool the climate, but would different countries agree on how much to reflect? Research by climate scientists at the University of Bristol shows that the impact of geoengineering would be felt in very different ways across the world.
Previous studies of geoengineering approaches, aimed at averting dangerous climate change, have shown that although the average global temperature could be restored to 'normal' levels, some regions would remain too warm, whereas others would 'overshoot' and cool to much. In addition, average rainfall would be reduced.
People in coastal and low land regions are most likely to look at human-caused global warming from the vantage point of ice melts and ocean level rises. They've got more to lose from rising ocean levels than they have to lose or gain from changes in local temperatures or rains. But in other areas impacts on crops or on average comfort will weigh more heavily.
Doing engineering to climate to cool the planet introduces other effects on precipitation and the temperature changes are not uniform.
Their analysis revealed that with increasing geoengineering strength, most regions become drier while others buck the trend and become increasingly wet. For example, the USA became drier with increasing geoengineering, and returned to normal conditions under half-strength geoengineering, whereas Australia became wetter, returning to normal conditions only for full strength geoengineering
Even within a single country there's no consistent net benefit or cost to climate engineering. If your daily experience is the weather of Fairbanks Alaska then warming will likely deliver a big net benefit. But Phoenix Arizona is already hot enough without any additional warming.
In a very wet region a decrease in rain intensity might be welcome. But in US Western states or Australia more rain would deliver a net benefit given already limited water supplies. Cooling would also enable more snow pack to survive into summer to supply more water for crops in dry months.
I expect climate engineering will be done eventually. But it will be highly divisive among nations because it will create winners and losers within and between nations.
Raising the albedo (reflectivity) of roofs and pavement with lighter colored and more reflective material could delay the effects of higher atmospheric CO2 by about 2 years.
In the latest study, the Berkeley Lab researchers and their collaborators used a detailed global land surface model from NASA Goddard Space Flight Center, which contained regional information on surface variables, such as topography, evaporation, radiation and temperature, as well as on cloud cover. For the northern hemisphere summer, they found that increasing the reflectivity of roof and pavement materials in cities with a population greater than 1 million would achieve a one-time offset of 57 gigatons (1gigaton equals 1 billion metric tons) of CO2 emissions (31 Gt from roofs and 26 Gt from pavements). That’s double the worldwide CO2 emissions in 2006 of 28 gigatons. Their results were published online in the journal Environmental Research Letters.
“These offsets help delay warming that would otherwise take place if actual CO2 emissions are not reduced,” says Surabi Menon, staff scientist at Berkeley Lab and lead author of the paper.
The benefits of this idea go beyond global warming. Another advantage would be cooler cities in the summer. Don't you just hate hot black pavement in the summer? The dark color of the pavement does less to warm up cold winters because there's less sun in the winter. So dark colors in building materials and pavement tend to intensify the difference between summer and winter weather.
One of the methods proposed to cool the planet involves building lots of large floating spray pump systems that would use wind or wave energy to spray water into the atmosphere. The purpose of the water would be to create more white clouds that would reflect away more sunlight and thereby cool the planet. Ken Caldeira and associates find that the ocean spray approach would increase the amount of precipitation on land.
Palo Alto, CA— One proposed emergency fix to halt global warming is to seed clouds over the ocean to make them more reflective, reducing the solar radiation absorbed by the Earth. But the scheme could also change global rainfall patterns, raising concerns of water shortages on land. A new study by the Carnegie Institution, in collaboration with the Indian Institute of Science, suggests that altered atmospheric circulation under the scheme in fact could increase monsoonal rains and cause the continents to become wetter, not drier, on average.
Whitening clouds over the ocean to reflect sunlight is one of several geoengineering schemes proposed to counter global warming. The whitening would be accomplished by reducing the size of the water droplets making up the clouds. "Rain clouds, which have big droplets, tend to be grey and absorb sunlight, whereas clouds with smaller droplets tend to be white and fluffy and reflect more sunlight to space," says co-author Ken Caldeira of the Carnegie Institution's Department of Global Ecology. "In practice this could be done by shooting a fine spray of seawater high into the air, where the tiny salt particles would create condensation nucleii to form small cloud droplets."
Cheaper ways to cool the planet exist. Silicon dioxide sprayed into the atmosphere might be the cheapest. The size of the fleet of automated water spraying ships strikes me as a lot more expensive. But increased precipitation might pay back the costs via higher crop yields and more water for cities.
Climate engineering without the continental drying.
To test the climate consequences of doing this, Caldeira and his coauthors* used a computer simulation of the global climate system in which atmospheric carbon dioxide concentrations were set at approximately twice that of present day. Cloud droplets over the oceans in the model were reduced in size to make the clouds more reflective. Clouds over land were unaltered. As expected, the whitened clouds reflected more solar radiation and offset the warming effect of the high carbon dioxide levels.
What surprised the researchers, however, was that the model showed that the oceanic clouds caused the land surface to become cooler and wetter on average. In previous climate simulations diminishing solar radiation by geoengineering had reduced precipitation on land. "The drying of the continents has been a major concern with regard to geoengineering," says Caldeira. But in the model the runoff from the continents increased by 7.5% globally, with the effect being strongest in the tropics.
I would guess that stationing the spray ships upwind of continents would deliver the most precipitation onto land. Especially dry coastal areas such as most of the US west coast might benefit from increased rains.
At a conference on the ethical, political, and scientific issues surrounding climate engineering Princeton University climate researcher Robert Socolow laid out a variety of scenarios in which countries decide to do climate engineering unilaterally.
In one, a single country unilaterally pumps aerosols into the stratosphere to block the Sun's rays and preserve — or perhaps create — a climate of its own liking. In another, climate policies result in a world full of forest plantations that are created solely to store the greatest possible amount of carbon, with no regard for preserving biodiversity. Or what if the very possibility of using geoengineering to mitigate climate change gives political leaders cover to say that greenhouse gases aren't a problem?
The morning after Socolow's sobering talk, the conference's scientific organizing committee released a summary statement, based on attendees' comments, that endorsed geoengineering research as a viable way of avoiding possibly catastrophic global warming. But participants came up short on their stated goal of formulating a set of guidelines and principles for scientists working in the field, and conference organizers promised further work on these in the coming weeks. Instead, it was Socolow's cautionary note that resonated as participants departed the beachside Asilomar Conference Center near Monterey, California. "We're scared, and nothing brings people together like fear," says Jane Long, associate director for energy and environment at Lawrence Livermore National Laboratory in California.
Climate engineering is cheap enough that many countries could carry it out on their own. Low lying Bangladesh with a GDP of about $80 billion could afford a few hundred million dollars worth of climate engineering to prevent the melting of Greenland and resulting flooding of much of Bangladesh. Only a large trade embargo or military attack could stop Bangladesh.
There is climate engineering as an accidental side effect and climate engineering done on purpose to do climate engineering. Currently we are getting climate engineering as a side effect. Is it ethical? Well, we've already decide to do it? Should it be approved by the UN? Well, again, we've already decided to do it. So why shouldn't a country do it on purpose if the goal is to neutralize what we are doing as a side effect?
As our understanding of how we impact climate becomes understood in greater detail the most compelling argument for intentional climate engineering is going to be that we need to counteract climate engineering we are already doing by accident. Those most motivated to do intentional climate engineering will be those most harmed by changes in climate. Looking at losing your city to rising waters? Time to start pumping silicon dioxide into the atmosphere. I'm thinking coastal nuclear power plants that would otherwise be submerged by rising water could be used for this purpose.
Now I hear some of you saying "but global warming is a fraud" and other phrases to that effect. But since climate engineering can be done quickly there'll be no need to start doing it until the evidence (e.g. rapid measurable melting in Greenland) becomes so compelling that the vast bulk of the population agree it is happening.
We ought to study climate engineering in advance to understand the trade-offs and risks of the various choices. We've got plenty of time sitting in 2010 to do that research. Best to understand this when we aren't yet in full panic mode.
Assuming humans do not go extinct we should be able to prevent future ice ages. NASA Goddard Institute director and climate scientist James Hansen's Storms of My Grandchildren: The Truth About the Coming Climate Catastrophe and Our Last Chance to Save Humanity has a relevant passage. He says the Earth won't experience ice ages as long as humans live here.
The size of continental-scale ice sheets is mind-boggling. Although thinner toward the edges, ice over New York towered several times higher than the Empire State building--thick enough to crush everything in today's New York City to smithereens. But not to worry--even though we sometimes hear geoscientists talk as if ice ages will occur again, it won't happen--unless humans go extinct. Forces instigating ice ages, as we shall see, are so small and slow that a single chlorofluorocarbon factory would be more than sufficient to overcome any natural tendency toward an ice age. Ice sheets will not descend over North America and Europe as long as we are around to stop them.
So stopping ice ages is no big deal. Those of us who live to the day when rejuvenation therapies stop the aging process will not have to worry about a new ice age several thousand years from now.
What I want to know: Are there chlorofluorocarbons that do not cause ozone layer damage? Or perhaps are there chlorofluorocarbons so potent as greenhouse gases that they can be used in concentrations too low to do much damage to the ozone layer?
What we will probably need to figure out much sooner: What's the safest way to cool the planet? Enhanced bright cloud formation? Sulfur aerosols? Silicon dioxide aerosols? A space-based approach with satellites to reduce sunlight to the Earth would cost orders of magnitude more than silicon dioxide. But satellites would allow for much more rapid and precise control.
One way to remove carbon dioxide from the atmosphere involves pumping deep and nutrient-rich water up to the surface where the nutrients will boost algae growth and thereby pull lots of carbon from the atmosphere as carbon gets fixed to hydrogen (to make sugars, fats. protein) by photosynthesis. But some researchers in Germany find that if the pumping system ever stops the rebound would be worse never intervening in the first place.
Pumping nutrient-rich water up from the deep ocean to boost algal growth in sunlit surface waters and draw carbon dioxide down from the atmosphere has been touted as a way of ameliorating global warming. However, a new study led by Professor Andreas Oschlies of the Leibniz Institute of Marine Sciences (IFM-GEOMAR) in Kiel, Germany, pours cold water on the idea.
"Computer simulations show that climatic benefits of the proposed geo-engineering scheme would be modest, with the potential to exacerbate global warming should it fail," said study co-author Dr Andrew Yool of the National Oceanography Centre, Southampton (NOCS).
Hundreds of millions of pipes would be needed. I wonder about the energy costs of such a scheme. The scheme at best would capture less than a tenth of annual carbon emissions.
A previous study, of which Yool was lead author, used an ocean general circulation model to conclude that literally hundreds of millions of pipes would be required to make a significant impact on global warming. But even if the technical and logistical difficulties of deploying the vast numbers of pipes could be overcome, exactly how much carbon dioxide could in principle be sequestered, and at what risk?
In the new study, the researchers address such questions using a more integrated model of the whole Earth system. The simulations show that, under most optimistic assumptions, three gigatons of carbon dioxide per year could be captured. This is under a tenth of the annual anthropogenic carbon dioxide emissions, which currently stand at 36 gigatons per year. A gigaton is a million million kilograms.
The biggest benefit would come from the cold water cooling nearby land masses.
One surprising feature of the simulations was that the main effect occurred on land rather than the ocean. Cold water pumped to the surface cooled the atmosphere and the land surface, slowing the decomposition of organic material in soil, and ultimately resulting in about 80 per cent of the carbon dioxide sequestered being stored on land. "This remote and distributed carbon sequestration would make monitoring and verification particularly challenging," write the researchers.
Stopping the pumps would result in higher CO2 than would have happened without the pumps.
More significantly, when the simulated pumps were turned off, the atmospheric carbon dioxide levels and surface temperatures rose rapidly to levels even higher than in the control simulation without artificial pumps. This finding suggests that there would be extra environmental costs to the scheme should it ever need to be turned off for unanticipated reasons.
"All models make assumptions and there remain many uncertainties, but based on our findings it is hard to see the use of artificial pumps to boost surface production as being a viable way of tackling global warming," said Yool.
I expect anyone still alive 50 years from now (and quite possibly sooner) will witness the use of large scale efforts to do climate engineering. The human impact on climate will continue to increase because human discount rates about the future are so high and lots of trends in land use amount to a big tragedy of the commons on a planetary scale. I hope the side effects of sulfur aerosols or silicon dioxide for cooling are minimal.
Painting roofs white in order to cool the planet has been proposed previously. Now some scientists do some computer modeling of the effects of more reflective roofing in cities.
BOULDER—Painting the roofs of buildings white has the potential to significantly cool cities and mitigate some impacts of global warming, a new study indicates. The new NCAR-led research suggests there may be merit to an idea advanced by U.S. Energy Secretary Steven Chu that white roofs can be an important tool to help society adjust to climate change.
But the study team, led by scientists at the National Center for Atmospheric Research (NCAR), cautions that there are still many hurdles between the concept and actual use of white roofs to counteract rising temperatures.
Whiter buildings in cities are of special interest because cities are warmer (especially in the summer) than surrounding regions. The buildings and roads of cities absorb more sunlight than the same areas absorbed before humans built the cities. "Hot time, summer in the city."
White roofs would make a substantial difference.
"Our research demonstrates that white roofs, at least in theory, can be an effective method for reducing urban heat," says NCAR scientist Keith Oleson, the lead author of the study. "It remains to be seen if it's actually feasible for cities to paint their roofs white, but the idea certainly warrants further investigation."
The study is slated for publication later this winter in Geophysical Research Letters. It was funded by the National Science Foundation, NCAR's sponsor.
One third of the urban heat island effect could be eliminated by painting all city roofs white (orby using white materials to make the roofs). Okay, so what would it take to remove the other two thirds of the effect?
Cities are particularly vulnerable to climate change because they are warmer than outlying rural areas. Asphalt roads, tar roofs, and other artificial surfaces absorb heat from the Sun, creating an urban heat island effect that can raise temperatures on average by 2-5 degrees Fahrenheit (about 1-3 degrees Celsius) or more compared to rural areas. White roofs would reflect some of that heat back into space and cool temperatures, much as wearing a white shirt on a sunny day can be cooler than wearing a dark shirt.
The study team used a newly developed computer model to simulate the amount of solar radiation that is absorbed or reflected by urban surfaces. The model simulations, which provide scientists with an idealized view of different types of cities around the world, indicate that, if every roof were entirely painted white, the urban heat island effect could be reduced by 33 percent. This would cool the world's cities by an average of about 0.7 degrees F, with the cooling influence particularly pronounced during the day, especially in summer.
I'm thinking white streets would get us part of the way there. Is it possible to develop a whiter concrete? Would such a concrete make streets too bright at mid day?
The extent of the urban heat effect on rural temperature monitoring stations that cease to be rural when economic development occurs around them is a problem with studies that attempt to track long term temperature changes. This problem became an issue in an important case of researchers accused of misrepresenting data from Chinese temperature monitoring stations (and see here for more details). Those two articles from The Guardian in England are worth a read.
Internationally coordinated research and field-testing on 'geoengineering' the planet's atmosphere to limit risk of climate change should begin soon along with building international governance of the technology, say scientists from the University of Calgary and the United States.
Collaborative and government-supported studies on solar-radiation management, a form of geo-engineering, would reduce the risk of nations' unilateral experiments and help identify technologies with the least risk, says U of C scientist David Keith, in an article published in the Jan. 27 online edition of Nature. Co-authors of the opinion piece are Edward Parson at the University of Michigan and Granger Morgan at Carnegie Mellon University.
"Solar-radiation management may be the only human response that can fend off rapid and high-consequence climate change impacts. The risks of not doing research outweigh the risks of doing it," says Keith, director of the Institute for Sustainable Energy, Environment and Economy's energy and environmental systems group and a professor in the Schulich School of Engineering.
Solar-radiation management (SRM) would involve releasing megatonnes of light-scattering aerosol particles in the upper atmosphere to reduce Earth's absorption of solar energy, thereby cooling the planet. Another technique would be to release particles of sea salt to make low-altitude clouds reflect more solar energy back into space.
It is cheap to do.
Long-established estimates show that SRM could offset this century's predicted global average temperature rise more than 100 times more cheaply than achieving the same cooling by cutting emissions, Keith notes. "But this low price tag raises the risks of single groups acting alone, and of facile cheerleading that promotes exclusive reliance on SRM."
The effects are rapid when nature releases large quantities of sulfur aerosols from a volcano.
SRM would also cool the planet quickly, whereas even a massive program of carbon dioxide emission cuts will take many decades to slow global warming because the CO2 already accumulated in the atmosphere will take many years to naturally break down. The 1991 eruption of Mount Pinatubo, for example, cooled the planet by about 0.5 degrees Celsius in less than a year by injecting sulphur into the stratosphere.
Pinatubo was small potatoes compared to Tambora in 1815 which caused crop failures for 2 years. But Tambora is small potates compared to Toba's eruption about 74,000 years ago. Another eruption like Toba would cause billions to die.
But if CO2 emissions keep rising and only aerosols are used to cool the planet then rains could decrease with resulting crop failures and other problems.
But a world cooled by managing sunlight will present risks, the scientists note. The planet would have less precipitation and less evaporation, and monsoon rains and winds might be weakened. Some areas would be more protected from temperature changes than others, creating local 'winners' and losers.'
The fact that climate engineering is possible and affordable is why I do not expect south Florida, most of Bangladesh, and other large low lying places won't be submerged by melting ice from Greenland and Antarctica. Push comes to shove we've got options. But we need to do the research in advance to learn about the scale and nature of side effects.
Update: Note that since climate engineering causes rapid changes in temperature we do not have to do it decades in advance of dangerous warming. Once it is obvious the Greenland or Antarctica ice is rapidly melting we can apply the brakes to the temperature rise at that point. Since people have such high discount rates with regard to future problems that seems the most likely scenario.
Writing in Technology Review Kevin Bullis reports that mainstream scientists are beginning to accept the necessity of climate engineering.
Atmospheric levels of carbon dioxide have already climbed to 385 parts per million, well over the 350 parts per million that many scientists say is the upper limit for a relatively stable climate. And despite government-led efforts to limit carbon emissions in many countries, annual emissions from fossil-fuel combustion are going up, not down: over the last two decades, they have increased 41 percent. In the last 10 years, the concentration of carbon dioxide in the atmosphere has increased by nearly two parts per million every year. At this rate, they'll be twice preindustrial levels by the end of the century. Meanwhile, researchers are growing convinced that the climate might be more sensitive to greenhouse gases at this level than once thought. "The likelihood that we're going to avoid serious damage seems quite low," says Schrag. "The best we're going to do is probably not going to be good enough."
This shocking realization has caused many influential scientists, including Obama advisors like Schrag, to fundamentally change their thinking about how to respond to climate change. They have begun calling for the government to start funding research into geoengineering--large-scale schemes for rapidly cooling the earth.
If the Earth heats up so much that major coastal cities are going to flood then I see climate engineering as inevitable as soon as the oceans rise by a meter or two. In fact, one could probably figure out for each nation with an ocean border how high the oceans would need to rise to cause its populace and leaders to switch toward favoring climate engineering.
However, I can see a possible exception: Russia. If Siberia warms up won't the Russians benefit far more from massive areas becoming livable than from the loss of part of St. Petersburg. Most of the Russian population isn't near coasts.
In some nations with limited water resources global warming might be seen as a big blessing if it boosts rainfall.
The various different engineering methods for cooling differ in many ways that will be debated in detail in coming decades. For example, some cooling gases stay in the atmosphere for a short time, others for a long time. It would probably make sense to start out with short duration cooling gases so that the effects of a cooling intervention won't be long lasting in case they cause side effects that are too problematic.
A big volcanic eruption that cools the Earth for a few years in the 2020s or 2030s might catalyze support for intentional cooling. A short cooling from a natural cause would serve as a powerful demonstration of the potential for engineered cooling under human control.
Update: Some people in the comments are obviously upset by the idea of intervening in the weather to solve a problem which they doubt really exists. Well, don't go getting your panties in a bunch. Climate engineering can be done very rapidly. Therefore it doesn't need to be started until major melting and ocean level rises are clearly underway. Spew a huge amount of silicon dioxide into the air for a year and you can bring on another ice age. This isn't rocket science. It isn't expensive either.
John Tierney points to discussions by climate scientists about whether to do climate engineering to prevent global warming. Tierney is confident that the nations of the world are not going to agree to huge sacrifices to cut back on carbon dioxide emissions. I tend to agree. So if CO2 really is going to warm the planet other measures will be needed to deal with it. So climate engineering is getting wider consideration.
The National Academy of Sciences and Britain’s Royal Society are preparing reports on climate engineering, and the Obama administration has promised to consider it. But so far there has been virtually no government support for research and development — certainly nothing like the tens of billions of dollars allotted to green energy and other programs whose effects on the climate would not be felt for decades.
For perhaps $100 million, climate engineers could begin field tests within five years, says Ken Caldeira of the Carnegie Institution for Science. Dr. Caldeira is a member of a climate-engineering study group that met last year at the Kavli Institute for Theoretical Physics under the leadership of Steven E. Koonin, who has since become the under secretary for science at the United States Department of Energy. The group has just issued a report, published by the Novim research organization, analyzing the use of aerosol particles to reflect shortwave solar radiation back into space.
Caldeira thinks we should test a cooling method well in advance of when we think we might need it. But other researchers fear side effects (e.g. decreased precipitation of rain and therefore crop failures) make such experiments too risky in advance of an acute need.
One of the methods mentioned is to squirt lots of ocean water into the atmosphere to increase white cloud formation and therefore to reflect more sunlight back into space. I would expect that technique to also increase precipitation (what goes up must come down eventually). While the rains wouldn't necessarily come where most needed I would expect they could in some instances. For example, wind-driven misting machines off the west coast of Canada and the United States could cause more rainfall over North American farm fields.
Since we have several ways to cool the planet which can be implemented quickly I think for now research on them ought to fall short of real experiments that alter our weather. Currently climate scientists are wrestling with the question of why haven't their temperature modeling stations detected any warming for the last 10 years? The last 10 years do not fit their models. Obviously their models are far from complete. The shorter term causes of variation aren't sufficiently well understood and so that makes picking up long term signals harder. What if some natural forcer is going to keep the planet from warming further for another 5-10 years?
The warming pause really points to a problem with climate engineering experiments: How to know whether, say, silicon dioxide or sulfur or water mists in a climate engineering experiment really did result in some cooling? One needs to have a certain degree of certainty about what the climate would be like without the intervention. If a climate engineering experiment had begun in 1999 the experimenters might have incorrectly concluded that their intervention caused the last 10 year warming pause.
The climate is an extremely complex system with lots of positive and negative feedbacks and multiple inputs. We do not have a couple dozen planets to experiment with in order to compare results of experiments and verify results. That's the fundamental problem with all climate research. There's a very limited potential for greater understanding thru experimentation. Yet experimentation is at the core of the scientific method.
In addition to multiple articles and books in the popular media, the United Kingdom's Royal Society, the authoritative national academy of science there, issued an in-depth review of geoengineering and President Obama's science advisor, John Holdren, has repeatedly stated that geoengineering must be on the table as a possible approach to addressing climate change.
Makes sense to debate and study the option decades before it might become necessary to use it.
Yesterday, the House of Representatives' Committee on Science and Technology held a hearing that its chairman, Bart Gordan (D-TN), said was, "the first time that a congressional committee has undertaken a serious review of proposals for climate engineering."
Gordan was quick to say that this doesn't mean he supported geoengineering, and that the consensus at the hearing seemed to be that no one should deploy geoengineering until we've done a lot more research.
I've been writing about climate engineering for years. My own take: Cooling the planet with aerosols or a huge array of reflective satellites might some day deliver a net benefit. But climate engineering is problematic for a few reasons:
So one needs to be looking at a pretty dire and certain future (e.g. big sea level rises flooding out southern Florida, New York City, Bangladesh, and London) before launching into such a drastic undertaking.
On the other hand, it is possible to wade into climate engineering with some measures that would be widely seen as quite innocuous. For example, building roofs, which are human constructions in the first place could all be painted white to delay global warming. US Energy Secretary Steven Chu sees white roofs as fairly benign. One could argue that white roofs and white roads would counteract changes in albedo that we caused in the first place by constructing dark roofs and black asphalt roads. So the argument will be made that roof painting represents a restoration of previous natural albedo.
My guess is we'll see policies put into place to do mild forms of climate engineering and once started down that path if the world really starts to heat up bigger and bigger interventions will get implemented.
The late oceanographer John Martin of the Moss Landing Marine Laboratories proposed over 20 years ago using iron fertilization of oceans to pull carbon dioxide out of the atmosphere to cool the planet. Lawrence Berkeley Lab oceanographers find the simplest iron fertilization approach disappoints by not permanently sequestering much carbon.
BERKELEY, CA – Oceanographers Jim Bishop and Todd Wood of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory have measured the fate of carbon particles originating in plankton blooms in the Southern Ocean, using data that deep-diving Carbon Explorer floats collected around the clock for well over a year. Their study reveals that most of the carbon from lush plankton blooms never reaches the deep ocean.
The surprising discovery deals a blow to the simplest version of the Iron Hypothesis, whose adherents believe global warming can be slowed or even reversed by fertilizing plankton with iron in regions that are iron-poor but rich in other nutrients like nitrogen, silicon, and phosphorus. The Southern Ocean is one of the most important such regions.
The scientists used floating autonomous sensor pods called Carbon Explorers that can take themselves down a few thousand feet and do continuous measurements for months. These pods collected the data that made this analysis possible. Deployment of a much larger number of Carbon Explorers would enable the scientists to develop a much more complex model of the ecosystem of phytoplankton and the zooplankton that feed on them.
The scientists aren't entirely dismissing the idea of using iron to pull carbon dioxide out of the atmosphere. But they think finding a way to do this requires development of a much more complex understanding of how to optimize phytoplankton growth.
The Iron Hypothesis isn’t wrong, but it’s much more subtle than usually stated. Achieving optimum carbon sedimentation from plankton growth may require the right “recipe” of iron and other trace nutrients to grow the right kind of phytoplankton. Says Bishop, “You can grow a lot of Brussels sprouts, but kids won’t eat it. The same appears to be the case with diatom phytoplankton and zooplankton. It’s the zooplankton community that determines carbon sedimentation.”
If we inject large amounts of sulfur particles in the atmosphere to cool the climate then the resulting diffusion of light will cut power output of concentration solar power installations by as much as a fifth. Photovoltaics and solar water heaters will not suffer as much loss of output.
The concept of delaying global warming by adding particles into the upper atmosphere to cool the climate could unintentionally reduce peak electricity generated by large solar power plants by as much as one-fifth, according to a new NOAA study. The findings appear in this week’s issue of Environmental Science and Technology.
“Injecting particles into the stratosphere could have unintended consequences for one alternative energy source expected to play a role in the transition away from fossil fuels,” said author Daniel Murphy, a scientist at NOAA’s Earth System Research Laboratory in Boulder, Colo.
The problem comes from diffused light which does not hit solar concentrators at the right angles.
Murphy found that particles in the stratosphere reduce the amount and change the nature of the sunlight that strikes the Earth. Though a fraction of the incoming sunlight bounces back to space (the cooling effect), a much larger amount becomes diffuse, or scattered, light.
On average, for every watt of sunlight the particles reflect away from the Earth, another three watts of direct sunlight are converted to diffuse sunlight. Large power-generating solar plants that concentrate sunlight for maximum efficiency depend solely on direct sunlight and cannot use diffuse light.
Murphy verified his calculations using long-term NOAA observations of direct and diffuse sunlight before and after the 1991 eruption.
After the eruption of Mt. Pinatubo, peak power output of Solar Electric Generating Stations in California, the largest collective of solar power plants in the world, fell by up to 20 percent, even though the stratospheric particles from the eruption reduced total sunlight that year by less than 3 percent.
Solar panels and solar hot water panels would suffer much less decrease in output. But passive solar house heating would become less effective.
Flat photovoltaic and hot water panels, commonly seen on household roofs, use both diffuse and direct sunlight. Their energy output would decline much less than that from concentrating systems.
Even low-tech measures to balance a home’s energy, such as south-facing windows for winter heat and overhangs for summer shade, would be less effective if direct sunlight is reduced.
Interesting result. Enhanced dimethyl sulfide (DMS) excretion by marine phytoplankton might be a low cost way to use the natural sulfur cycle to cool the planet. The silicon dioxide approach would cool the planet for a very low cost. A massive satellite-based reduction of insolation would avoid the diffuse light problem. But the cost would be much higher. Though one group proposes a satellite approach which they claim would cost only a half trillion dollars. Another and much lower tech way to cool the planet: paint all rooftops white. Throw in the use of lighter colored materials for road construction and we could achieve an even greater increase in albedo.
Another problem with reduced insolation: less rainfall. But a satellite approach might be able to reduce that side effect by selectively reducing sunlight only on deserts and therefore plenty of sunlight would still hit ocean surfaces and cause evaporation.
We should use more nuclear, wind, solar, and geothermal power now so we can save fossil fuels to use later to delay the next ice age.
Professor Shaffer made long projections over the next 500,000 years with the DCESS Earth System Model to calculate the evolution of atmospheric CO2 for different fossil fuel emission strategies. He also used results of a coupled climate-ice sheet model for the dependency on atmospheric CO2 of critical summer solar radiation at high northern latitudes for an ice age onset.
The results show global warming of almost 5 degrees Celsius above present for a "business as usual" scenario whereby all 5000 billion tons of fossil fuel carbon in accessible reserves are burned within the next few centuries. In this scenario the onset of next ice age was postponed to about 170,000 years from now.
Carbon can postpone ice age
However, for a management scenario whereby fossil fuel use was reduced globally by 20% in 2020 and 60% in 2050 (compared to 1990 levels), maximum global warming was less than one degree Celsius above present. Similar reductions in fossil fuel use have been proposed by various countries like Germany and Great Britain.
In this scenario, combustion pulses of large remaining fossil fuel reserves were then tailored to raise atmospheric CO2 content high and long enough to parry forcing of ice age onsets by summer radiation minima as long as possible. In this way our present equable interglacial climate was extended for about 500,000 years, three times as long as in the "business as usual" case.
Sounds like a good idea to me. Though we could always use nuclear fusion reactions to drive synthetic production of methane for a much more powerful greenhouse gas.
In any case, we've already kicked the next ice age 55,000 years into the future. So we've got that going for us. Which is nice.
"It appears to be well established that the strong ice ages the Earth has experienced over the past million years were ushered in by declining levels of atmospheric CO2. Our present atmospheric CO2 level of about 385 parts per million is already higher than before the transition to these ice ages" Professor Shaffer notes and adds that "The Earth's orbit is nearly circular at present meaning that the present minimum in summer radiation at high northern latitudes is not very deep. We have already increased atmospheric CO2 enough to keep us out of the next ice age for at least the next 55,000 years for this orbital setup".
Tim Lenton of the University of East Anglia, UK has released a comparison of methods for climate engineering to cool the planet.
Lenton's calculations show the only methods powerful enough to have a significant effect in the relatively short term (in the second half of this century) involve placing physical barriers between Earth and the Sun. This would involve either orbiting space mirrors, stratospheric mists of sulphur, or using seawater to make reflective clouds.
But Lenton warns that these options also carry the most risk. A sulphur sunshade could reduce radiative forcing by 3.7 W/m2, but would have to be continually replenished. If it was allowed to disappear, temperatures could shoot up by as much as 5 °C within decades (Climatic Change, DOI: 10.1007/s10584-008-9490-1).
I see the ability to quickly decrease the sunshade as a feature, not a defect. If we use satellites then even a partial collapse of civilization wouldn't prevent a single country from maintaining control of already launched satellites. Also, the costs of silicon dioxide for cooling are so low that we'd need to experience a total civilizational collapse (in which case most of us will die anyway) to lose the ability to keep releasing it.
Another recent research report throws doubt on the efficacy of ocean iron fertilization for atmospheric CO2 removal. Attempts to conduct iron fertilization research run into political opposition.
We aren't going to melt Antarctica and Greenland because if the melting becomes a big problem we can just cool the planet with climate engineering.
Still, I think we should stop building coal electric plants and start building nuclear power plants instead just to cut emissions of particulates, mercury, and oxides of sulfur among other pollutants. Also, when the planet starts cooling for the next ice age we might want to have all that coal available to burn for CO2 when we really could benefit from the CO2. Liquid Fluoride Thorium reactors might be the ticket.
In recent years, there has been growing evidence for the hypothesis that the effect of the pandemics in the Americas wasn't confined to killing indigenous peoples. Global climate appears to have been altered as well.
Stanford University researchers have conducted a comprehensive analysis of data detailing the amount of charcoal contained in soils and lake sediments at the sites of both pre-Columbian population centers in the Americas and in sparsely populated surrounding regions. They concluded that reforestation of agricultural lands—abandoned as the population collapsed—pulled so much carbon out of the atmosphere that it helped trigger a period of global cooling, at its most intense from approximately 1500 to 1750, known as the Little Ice Age.
"We estimate that the amount of carbon sequestered in the growing forests was about 10 to 50 percent of the total carbon that would have needed to come out of the atmosphere and oceans at that time to account for the observed changes in carbon dioxide concentrations," said Richard Nevle, visiting scholar in the Department of Geological and Environmental Sciences at Stanford. Nevle and Dennis Bird, professor in geological and environmental sciences, presented their study at the annual meeting of the American Geophysical Union on Dec. 17, 2008.
We change the climate with our actions. We probably prevented an Ice Age thousands of years ago. Now these Stanford researchers think we contributed to the Little Ice Age of a few hundred years ago.
What we do and what we do not do changes the climate. We have been unknowing climate engineers for thousands of years. We should get more intentional about it. If we paid women to have fewer children we could cool the Earth by gradually shrinking the human population. A return of trees would lower atmospheric CO2.
SAN FRANCISCO — The common wisdom is that the invention of the steam engine and the advent of the coal-fueled industrial age marked the beginning of human influence on global climate.
But gathering physical evidence, backed by powerful simulations on the world's most advanced computer climate models, is reshaping that view and lending strong support to the radical idea that human-induced climate change began not 200 years ago, but thousands of years ago with the onset of large-scale agriculture in Asia and extensive deforestation in Europe.
What's more, according to the same computer simulations, the cumulative effect of thousands of years of human influence on climate is preventing the world from entering a new glacial age, altering a clockwork rhythm of periodic cooling of the planet that extends back more than a million years.
"This challenges the paradigm that things began changing with the Industrial Revolution," says Stephen Vavrus, a climatologist at the University of Wisconsin-Madison's Center for Climatic Research and the Nelson Institute for Environmental Studies. "If you think about even a small rate of increase over a long period of time, it becomes important."
Was this intervention morally wrong? Should some ancient Al Gorestone have lobbied Fred Flintstone and Barney Rubble to stop using agriculture?
While I do not see how climate engineering can prevent the oceans from becoming too acidic from dissolved CO2 I do not have a problem with using climate engineering. If climate engineering was good enough for Trog then it is good enough for me. But some scientists are skeptical that we can use climate engineering successfully.
Global warming, some have argued, can be reversed with a large-scale "geoengineering" fix, such as having a giant blimp spray liquefied sulfur dioxide in the stratosphere or building tens of millions of chemical filter systems in the atmosphere to filter out carbon dioxide.
But Richard Turco, a professor in the UCLA Department of Atmospheric and Oceanic Sciences and a member and founding director of UCLA's Institute of the Environment, sees no evidence that such technological alterations of the climate system would be as quick or easy as their proponents claim and says many of them wouldn't work at all.
Turco will present his new research on geoengineering — conducted with colleague Fangqun Yu, a research professor at the State University of New York–Albany's atmospheric sciences research center — today and Thursday at the American Geophysical Union's annual meeting in San Francisco.
"We're talking about tinkering with the climate system that affects everybody on Earth," said Turco, an atmospheric chemist with expertise in the microphysics of fine particles suspended in the atmosphere. "Some of the ideas are extreme. There would certainly be winners and losers, but no one would know who until it's too late.
Climate engineering would create different winners and losers than reduced CO2 emissions would create. But either way there are going to be winners and losers. Also, if we do not restrict CO2 emissions there'll be winners and losers. Certainly that makes it very hard to form a consensus on the decision to do climate change. But should that be an argument to totally abandon intentional climate engineering? If we place intentional climate engineering beyond the pale we will just get unintentional climate engineering. That's what Fred and Wilma did way back when.
A Russian professor at an Ohio university has applied to patent a method for snuffing out hurricanes by flying jet fighters around the eye of the storm at supersonic speeds.
Professor Arkadii Leonov and his collaborator Atanas Gagov, both of Akron Uni, actually filed their patent application "Hurricane Suppression by Supersonic Boom" last year. It was unearthed by the New Scientist patents column this week.
The article points out that The US Air Force's new F-22 Raptors can sustain supersonic speed without afterburners. They would need to make several big circles around the hurricane. So they might need either refueling or multiple Raptors to do the job. Will the USAF include this potential capability as a justification to avoid budget cuts?
Jet fighters flying at supersonic speeds along special trajectories with a hurricane/typhoon at various altitudes would create supersonic booms. In one such embodiment, the trajectories for the supersonic booms of the present invention are counter to the rotational component of the hurricane and/or typhoon being targeted. As such, supersonic booms can be tailored and/or designed to partially and/or fully -negate the basic rotational contribution in a hurricane by slowing down a hurricane's/typhoon's rotation. Additionally, when supersonic booms propagate downward to the surface of the ocean they also destabilize a hurricane's/typhoon's structure by increasing the pressure in the central part of a hurricane's/typhoon's eye.
The patent cites other proposed methods of hurricane suppression including cloud seeding and pumping water from deep to the surface to lower surface temperatures.
To date a number of methods/theories relating to hurricane/typhoon control, dissipation and/or suppression have been offered. Most have focused on ways to achieve air cooling, considered by their proponents as a main source and/or reason for the continuance of hurricane/typhoon strength. One early attempt slightly reduced a hurricane's intensity by dispersing at high altitude silver iodine particles. This caused an increase in condensation in the seeded portion of the cloud mass of a hurricane and a heat-reducing (or cooling) rainfall. Another mitigation proposal focused on cooling a large area of ocean by pumping cold sea water from well below the surface of the ocean. Also forwarded as a possible hurricane/typhoon control, dissipation and/or suppression methods is the use of various powdered chemicals to achieve a cooling (or exothermic) effect within a hurricane/typhoon. Unfortunately, the most effective endothermic chemicals are detrimental to the environment and expensive. Environmentally friendly chemicals such as potassium chloride (KCI) are cheap and easy to use, but not very effective as the amount needed to actually impact a hurricane/typhoon is on the order of about 40 tons per second of KCI in an area having a radius of about 20 km to about 30 km around a hurricane's/typhoon's eye wall. This amount of powdered KCI is generally necessary in order to achieve 0.80C cooling under ideal conditions. Accordingly, it is believed that such methods are unrealistic for one reason or another.
The water pump approach sounds capital intensive. One big advantage of the supersonic aircraft approach is that the aircraft are going to exist anyway and would be available for use against the occasional category 4 or category 5 hurricane.
It turns out that a 1,000 square foot area of rooftop painted white has about the same one-time impact on global warming as cutting 10 tons of carbon dioxide emissions, he and his colleagues write in a new study soon to be published in the journal “Climatic Change.”
As sunlight pours down into Earth’s atmosphere, some of the energy is filtered out or bounces off clouds. About half the energy shines through as visible light and some of that hits the tops of houses. If a roof is white, most sunlight reflects back into space and doesn’t heat the earth. But if a roof is a dark color, the sunlight converts to heat rather than bouncing off as light. That thermal energy then radiates off the roof back toward space, where it is trapped by CO2 in the atmosphere, and then absorbed by this greenhouse gas. As a result, the world’s thermometer reads just a little higher than it did before.
If the estimated 360,000 square miles (less than 1 percent of the world’s land surface) covered by urban rooftops and pavement were a white or light color, enough sunlight would be reflected back into space to delay climate change by about 11 years, the study shows.
Put another way, boosting how much urban rooftops reflect, called albedo (al-BEE-doh) in scientific terms, would be a one-time carbon-offset equivalent to preventing 44 billion tons of CO2 from entering the atmosphere, Akbari says. It’s about the same as taking all the earth’s automobiles off the road for 11 years, the study’s authors say.
So if global warming becomes a problem we've got a cheap low tech thing we can do to delay the effects. The cooler buildings in tropical and temperate zones will cost less to air condition as well.
On the other hand, our clean energy sun is absolutely spotless. If it stays spotless then we'll need to paint everything black instead.
Sept. 30, 2008: Astronomers who count sunspots have announced that 2008 is now the "blankest year" of the Space Age.
As of Sept. 27, 2008, the sun had been blank, i.e., had no visible sunspots, on 200 days of the year. To find a year with more blank suns, you have to go back to 1954, three years before the launch of Sputnik, when the sun was blank 241 times.
"Sunspot counts are at a 50-year low," says solar physicist David Hathaway of the NASA Marshall Space Flight Center. "We're experiencing a deep minimum of the solar cycle."
But if photovoltaics become really cheap in the next 10 years (and I expect they will) then people will put PV on their rooftops and the PV material will absorb more light than white-painted roofing. What will be the net climate effect of massive PV installation? The PV electricity will displace some usage of fossil fuels. But the PV might lower the Earth's albedo (i.e. lower the amount of light reflected into space).
Planting trees also lowers the Earth's albedo because trees are often darker than the surface without trees. But trees gather solar energy and can be burned in place of fossil fuels as well.
Use of whiter materials for laying pavement offers another way to raise the Earth's albedo that won't compete with PV for the Earth's surface.
COLUMBIA, Mo. —The battle to reduce carbon emissions is at the heart of many eco-friendly efforts, and researchers from the University of Missouri have discovered that nature has been lending a hand. Researchers at the Missouri Tree Ring Laboratory in the Department of Forestry discovered that trees submerged in freshwater aquatic systems store carbon for thousands of years, a significantly longer period of time than trees that fall in a forest, thus keeping carbon out of the atmosphere.
“If a tree is submerged in water, its carbon will be stored for an average of 2,000 years,” said Richard Guyette, director of the MU Tree Ring Lab and research associate professor of forestry in the School of Natural Resources in the College of Agriculture, Food and Natural Resources. “If a tree falls in a forest, that number is reduced to an average of 20 years, and in firewood, the carbon is only stored for one year.”
We could store trees underwater in ways that could last tens of thousands of years if we wanted to put some thought in how to do it.
Submerged oak trees in Missouri are as old at 14,000 years.
The team studied trees in northern Missouri, a geographically unique area with a high level of riparian forests (forests that have natural water flowing through them). They discovered submerged oak trees that were as old as 14,000 years, potentially some of the oldest discovered in the world. This carbon storage process is not just ancient; it continues even today as additional trees become submerged, according to Guyette.
Suppose we systematically started sinking trees at the bottom of the Mississippi River with weights. One cool advantage of this idea: If (or rather when) we start to slip into another ice age we could bring those trees back up to the surface, let them dry out, and then burn them to release the CO2 and slow the cooling.
Alternatively, could we come up with a coating for trees that would last thousands of years? Or just use trees to fill in a massive coal mine dig with a bottom coating that would hold water and then cover over it with a material that would keep out air? Maybe a solid salt layer?
Liberia's greenhouse gas emissions are roughly 250,000 times lower than those of the US, yet its remaining forests store approximately four billion tonnes of carbon dioxide (CO2), equivalent to the amount emitted by 57 million cars over 10 years.
However, the amount of tropical forest our planet loses each year is one-and-a-half times the size of Liberia, releasing almost 20% of total greenhouse gas emissions - more than all the world's cars, trucks and planes combined.
If all the tropical forests torn down to make room for crops to make ecologically friendly (snicker) biomass energy were submerged then the initial tree destruction wouldn't cause a large CO2 level rise as it does now.
The further you move from the equator, though, these gains are eroded; and the team's modelling predicts that planting more trees in mid- and high-latitude locations could lead to a net warming of a few degrees by the year 2100.
"The darkening of the surface by new forest canopies in the high-latitude boreal regions allows absorption of more sunlight that helps to warm the surface," Dr Bala said.
But the long run effect of planting a series of tree crops and then submerging them would eventually outweigh the warming effect of the darker color of trees. Also, if existing forests get cut down, their trees submerged, and then new trees planted those new trees wouldn't be any darker than the trees they replaced.
Researchers at Lawrence Livermore National Laboratory, led by atmospheric scientist Govindasamy Bala, find that climate engineering to cancel the warming effects of CO2 would reduce net global rainfall.
In the new climate modeling study, which appears in the May 27-30 early online edition of the Proceedings of the National Academy of Sciences, Bala and his colleagues Karl Taylor and Philip Duffy demonstrate that the sunshade geoengineering scheme could slow down the global water cycle.
The sunshade schemes include placing reflectors in space, injecting sulfate or other reflective particles into the stratosphere, or enhancing the reflectivity of clouds by injecting cloud condensation nuclei in the troposphere. When CO2 is doubled as predicted in the future, a 2 percent reduction in sunlight is sufficient to counter the surface warming.
This new research investigated the sensitivity of the global mean precipitation to greenhouse and solar forcings separately to help understand the global water cycle in a geoengineered world.
While the surface temperature response is the same for CO2 and solar forcings, the rainfall response can be very different.
“We found that while climate sensitivity can be the same for different forcing mechanisms, the hydrological sensitivity is very different,” Bala said.
The global mean rainfall increased approximately 4 percent for a doubling of CO2 and decreases by 6 percent for a reduction in sunlight in his modeling study.
“Because the global water cycle is more sensitive to changes in solar radiation than to increases in CO2, geoengineering could lead to a decline in the intensity of the global water cycle” Bala said.
Sunlight is probably more important than global atmospheric since the sunlight hits the surface of the oceans and cause more localized heating right on the surface of the oceans where the heat does the most to cause water to evaporate.
I can imagine at least one method to counteract the reduction in water evaporation: Use large floating windmills on the ocean to pump up and spray water into the atmosphere. But I have no idea what scale of windmills would be needed to do this. I suspect it would not be cost effective.
Here's another idea: Use satellites to block sunlight from hitting Earth. But only block the sunlight over land. That way the oceans would still get the full force of solar radiation. Still, satellites are a far more expensive way to reduce solar radiation as compared to spraying aerosols into the atmosphere. So this approach has problems as well.
Anyone have a good idea on how to climate engineer to lower temperatures without lowering water evaporation from the oceans?
Stressed kelp cause more reflective cloud formation. Could their growth be boosted on a large scale as a way to cause global cooling?
Scientists at The University of Manchester have helped to identify that the presence of large amounts of seaweed in coastal areas can influence the climate.
A new international study has found that large brown seaweeds, when under stress, release large quantities of inorganic iodine into the coastal atmosphere, where it may contribute to cloud formation.
A scientific paper published online today (Monday 6 May 2008) in the Proceedings of the National Academy of Science (PNAS) identifies that iodine is stored in the form of iodide – single, negatively charged ions.
Can you think of a way to increase the area of kelp growth in order to boost cloud formation? Seems hard to do. The press release says the kelp need intertidal zones. Most of the ocean seems unsuited and hard to make suitable.
The paper’s co-author, Dr Gordon McFiggans, an atmospheric scientist from The University of Manchester’s School of Earth, Atmospheric and Environmental Sciences (SEAES) said: “The findings are applicable to any coastal areas where there are extensive kelp beds. In the UK, these are typically place like the Hebrides, Robin Hood's Bay and Anglesey. The kelps need rocky intertidal zones to prosper - sandy beaches aren't very good.
“The increase in the number of cloud condensation nuclei may lead to ‘thicker’ clouds. These are optically brighter, reflecting more sunlight upwards and allowing less to reach the ground, and last for longer. In such a cloud there are a higher number of small cloud droplets and rainfall is suppressed, compared with clouds of fewer larger droplets.
“The increase in cloud condensation nuclei by kelps could lead to more extensive, longer lasting cloud cover in the coastal region – a much moodier, typically British coastal skyline.”
A flat area near a coastline, if flooded, might be convertible into a massive kelp bed. Seems very expensive to do though.
The most extensive operations are taking place in China, however. Here, for example, weather-modification "authorities" use conventional military weaponry to bombard clouds with silver-iodide particles. Under the guidance of the China Meteorological Administration (CMA), local "weather changing" offices employ some 39,000 staff equipped with 7,113 anti-aircraft cannons, which, in 2006, were used to fire a million rounds of silver iodide into the atmosphere (with the country spending over $100m a year in the process). The Chinese state news agency claims that between 1999 and 2006, China produced 250 billion metric tonnes of artificial rain, though researchers take this with a pinch of salt.
The Chinese have gone public with their intention to stop drizzle ruining the opening ceremony of the 2008 Olympics.
Think the world can be convinced to give up crop genetic engineering, human genetic engineering, weather modification, or continual construction of large numbers of coal electric plants? Not with the rise of China. The Chinese remind me of America in the 1950s.
New technologies let researchers follow atmospheric events as they happen, says Roelof Bruintjes of the US National Center for Atmospheric Research, Colorado. "This really is a new era of weather modification."
"There have been big improvements in radar, satellites, and airborne instrumentation, and unmanned aerial vehicle technology," says Joe Golden of the National Oceanic and Atmospheric Administration in Washington, DC, US.
Bruintjes is skeptical of China's claims because they rely on the results of studies done in the 1960s and 70s before the complexity of Earth's weather was fully understood and there is little data to back-up claims of success.
"There is no evaluation, there is no scientific literature available that can substantiate their claims," he said.
Imagine what China will do once weather modification works well.
One of the world's leading experts on weather modification, Bruintjes has helped design cloud seeding and other weather modification programs on every continent except Antarctica. His work focuses primarily on attempts to enhance rainfall in arid and semi-arid regions of the world, including ongoing projects in Wyoming, Australia, Turkey, the Middle East, and West Africa. He has also consulted with Chinese experts about their programs in rainfall enhancement and prevention. In addition to evaluating various cloud seeding technologies, Bruintjes researches inadvertent weather modification, including the effects of smoke and pollution on clouds and rainfall.
People around the world are going to modify the weather. One can easily imagine conflicts between nations because a country that is more upstream causes water to come down on their territory leaving less water to rain down on a country that is more downstream.
A recent gathering of weather modification experts in Westminster Colorado called for a restart of research efforts to develop weather modification technologies.
It's high time the federal government fund research in modifying the weather to bring more rain to the thirsty West and to slow down deadly hurricanes, top scientists said Tuesday.
The brainpower is available, instrumentation is vastly improved, but the feds haven't funded weather-modification research since the mid-1990s, Joe Golden, a scientist specializing in atmospheric modification, said at an international symposium being held this week in Westminster.
The US Department of Homeland Security asked Joe Golden to gather together experts to discuss the idea of diverting hurricanes. Golden and his colleagues think research efforts should aim at diverting and weakening hurricanes.
The hurricane diversion argument seems compelling. Imagine that aircraft had seeded Hurricane Katrina before it approached the Louisiana coast. Tens of billions of dollars of damage might have been avoid.
One of the many methods for cooling the planet would cause an undesirable destruction of ozone over Antarctica. So then which other methods of planet cooling would avoid this problem?
BOULDER--A much-discussed idea to offset global warming by injecting sulfate particles into the stratosphere would have a drastic impact on Earth's protective ozone layer, new research concludes. The study, led by Simone Tilmes of the National Center for Atmospheric Research (NCAR), warns that such an approach might delay the recovery of the Antarctic ozone hole by decades and cause significant ozone loss over the Arctic.
The study will be published Thursday in Science Express. It was funded by the National Science Foundation, which is NCAR's principal sponsor, as well as by NASA and European funding agencies.
"Our research indicates that trying to artificially cool off the planet could have perilous side effects," Tilmes says. "While climate change is a major threat, more research is required before society attempts global geoengineering solutions."
In recent years, climate scientists have studied "geoengineering" proposals to cool the planet and mitigate the most severe impacts of global warming. Such plans could be in addition to efforts to reduce greenhouse gas emissions. One of the most-discussed ideas, analyzed by Nobel laureate Paul Crutzen and other researchers, would be to regularly inject large amounts of Sun-blocking sulfate particles into the stratosphere. The goal would be to cool Earth's surface, much as sulfur particles from major volcanic eruptions in the past have resulted in reduced surface temperatures.
Why aren't governments regulating the emissions of volcanoes? Shouldn't volcanoes have to apply for a permit to do a very polluting eruption? I'm just asking.
Simone Tilmes and co-workers already knew about the problem caused by sulfates from volcanoes. So they had reason to try to model the effects when sulfates would be released intentionally by humans.
To determine the relationship between sulfates and ozone loss, the authors used a combination of measurements and computer simulations. They then estimated future ozone loss by looking at two geoengineering schemes--one that would use volcanic-sized sulfates and a second that would use much smaller injections.
The study found that injections of small particles, over the next 20 years, could reduce the ozone layer by 100 to 230 Dobson Units. This would represent a significant loss of ozone because the average thickness of the ozone layer in the Northern Hemisphere is 300 to 450 Dobson Units. (A Dobson Unit is equivalent to the number of ozone molecules that would create a layer 0.01 millimeters thick under conditions at Earth's surface).
With large particles, the Arctic loss would range from 70 to 150 Dobson Units. In each case, the larger figure is correlated with colder winters.
But if rising CO2 emissions are going to bring on a global warming disaster then a partial loss of ozone might be a price worth paying to prevent it. However, note that these researchers studied the effects of sulfates which are already thought to destroy ozone when released by volcanoes. We have other choices. Gregory Benford proposes the use of silicon dioxide as the preferred cooling agent. Will Benford's proposal run into the same problem? Does silicon dioxide interact with ozone? It is a really cheap way to do a world wide cooling.
Another method of cooling the planet uses enhanced dimethyl sulfide (DMS) production from marine phytoplankton. Salt the oceans with iron and let nature produce the cooling agent. This happens naturally all the time. Will it damage ozone?
Govindasamy Bala, an atmospheric scientist at the East Bay's Lawrence Livermore National Laboratory, discussed a climate model he recently completed. By putting aerosols in the stratosphere to reflect sunlight, he found the amount of sunlight that reaches the Earth's surface could be reduced by 2 percent - enough to counterbalance the doubling of carbon dioxide. On the other hand, he emphasized, the climate reacted more strongly to the aerosols than the carbon dioxide, resulting in less global average rainfall.
"I don't think our understanding of the climate system is now complete in order for us to start with geoengineering," Bala said.
Could another technique combined with the aerosols boost precipitation? If so, what would do it? Cloud seeding? Methods to spray water into the atmosphere to get more water to evaporate? How to do that without using fossil fuels energy? Floating windmills to power water spray pumps?
But aerosols aren't the only way to address the problem. Ken Caldeira opposes using sulphate aerosols to cool the Earth but Caldeira and Govindasamy think reflecting light away with a physical reflective material might work better than an aerosol.
A few years ago, Dr Caldeira set out to disprove an idea put forward by Livermore physicists Lowell Wood and Edward Teller to cool the Earth with a sheet of superfine reflective mesh - similar in concept to orbiting mirrors.
In a computer model, Dr Caldeira and colleague Bala Govindasamy simulated the effects of diminished solar radiation.
"We were originally trying to show that this is a bad idea, that there would be residual regional and global climate effects," explains Dr Caldeira.
"Much to our chagrin, it worked really well."
But mirrors and other physical surfaces for reflecting light might also reduce precipitation.
My problem with the light reflection schemes is that they don't prevent higher CO2 concentrations from dissolving into the oceans to form a mild acid that acidifies the oceans. If that acidification is a problem then light reflection by itself doesn't address what might be the biggest problem with atmospheric CO2 build-up.
Pulling CO2 out of the atmosphere by seeding oceans with iron is another option. The iron would allow more algae to grow and the algae would convert dissolved CO2 into hydrocarbon materials, a portion of which would sink to the ocean floor. Dutch aquatic microbiologist Jef Huisman says iron fertilization to extract CO2 from the atmosphere seems a risky way to do climate engineering.
Asked about the research about to be conducted by Planktos, Professor Huisman said: I think it's an interesting idea as well as a dangerous idea. Interesting because we know that if we can increase the primary production and there will be a larger intake of carbon dioxide in to the ocean.
"But is also dangerous. Just as you fertilize on land you will change the eco-system. Whereas we have experience of what happens in a meadow, we have no experience of what would happen with the eco-system species composition in the ocean. What happens if you do large scale iron fertilization? We have no idea which species are going to profit or whether it will cause harmful algal blooms.
Professor Huisman predicts that once the iron goes into the ocean that there will be a strong increase in phytoplankton species.
"I would expect the small phytoplankton species -- that have a fast growth rate - will be there first," he said. "Secondly you would have slow plankton species that would catch up and start grazing on the phytoplankton species."
But you have to weigh risks against other risks. The Chinese and Indians aren't going to stop their rising consumption of fossil fuels unless either fossil fuels reserves start running out or we find cheaper alternative sources of energy. I am expecting oil and natural gas production to peak in the next decade. But coal reserves might be large enough (it is not clear) to melt the polar ice caps.
Big phytoplankton blooms could be harnessed in aquaculture. Create enclosed areas in the middle of oceans in areas where iron shortages prevent phytoplankton growth. Seed with iron. Put in fish. Let them eat the phytoplankton. Harvest the fish. Feed an unfortunately growing world population and extract CO2 from the atmosphere at the same time.
The way I see it we need replacements for fossil fuels regardless of whether Peak Coal is nearing. If Peak Coal is a distant prospect then we need alternatives because coal is a big conventional source of pollution (and I really wish the harm from conventional pollution got half the press that global warming receives since particulates and mercury really are bad for you). Cheaper alternatives to coal would displace coal and we'd get cleaner air and water. If Peak Coal is coming soon along with Peak Oil and Peak Natural Gas then we need some other way to power civilization or else our living standards will plummet. Either way we need cheaper cleaner sources of energy.
Well, readers Alex and Brock both draw my attention to one possibility: 200 kilowatt Toshiba micro nuclear plants might bring cheap nuclear power to small communities, big buildings or city blocks.
When next summer's Olympics roll around, the Beijing Weather Modification Office will be poised to intercept incoming clouds, draining them before they get to the festivities. No fewer than 32,000 people nationwide are employed by the Weather Modification Office -- "some of them farmers, who are paid $100 a month to handle anti-aircraft guns and rocket launchers" loaded with cloud-seeding compounds. Some estimate that up to 50 billion tons of artificial rain will be produced by 2010. But Taylor noted that this has resulted in competition between cities to seed clouds first, and bitter acrimony when when region receives water claimed by another.
This reminds me of cities and states in the US West (and other parts of the world) fighting over who gets to use the water in rivers passing through their territories. The Colorado River turns into a trickle by the time it reaches Mexico.
But atmospheric tinkering is likely to have much further reaching effects than using water out of rivers. Clouds probably bring a lot more water across international borders than rivers do. Also clouds, by their very presence, cause light to be reflected into space. Reduce cloud cover by massive seeding projects for rain and the net effect is probably to warm the Earth. But Willie Nelson might be tempted. There's only going to be blue skies for now on.
Weather delivers great benefits but also inflicts large costs. The development of cheap climate engineering technologies will provide a big temptation to reduce the costs. For example, hurricane cloud seeding could reduce hurricane intensity and even change hurricane direction.
Moshe Alamaro, of the Massachusetts Institute of Technology (MIT), told The Sunday Telegraph of his plans to "paint" the tops of hurricanes black by scattering carbon particles – either soot or black particles from the manufacture of tyres – from aircraft flying above the storms. The particles would absorb heat from the sun, leading to changes in the airflows within the storm. Satellites could also heat the cloud tops by beaming microwaves from space.
"If they're done in the right place at the right time they can affect the strength of the hurricane," Mr Alamaro said.
Imagine a category 3 hurricane (similar to the 1938 Long Island Express hurricane) was bearing down on Manhattan. Would it be worth it to shift its land collision point toward an outlying suburb on Long Island or New Jersey? The total amount of damage caused might be reducible by an order of magnitude. But who suffers the damage changes with the directional shift.
A massive hurricane is about to cause tens of billions of dollars in damage to New York City. Picture insurance companies offering to pay the losses of all the uninsured of Long Island if the US government agrees to divert a hurricane away from New York City. A good idea?
About global warming: China is establishing an interesting precedent. By intervening routinely in the climate it is making it easier for other governments to do as well. Suppose global warming becomes a real problem. What's to stop, say, India and Bangladesh from using cheap climate engineering in order to easily reverse a warming trend? If the rest of the world makes the planet heat up (and I'm not saying this is really going to happen) then why shouldn't India and Bangladesh use climate engineering to prevent melting water from submerging their lowlands?
Frank Zeman and Klaus Lackner have proposed a way to extract carbon dioxide from the atmosphere in order to prevent global warming, but at what cost?
Removing CO2 from the atmosphere is the subject of a prize announced earlier in 2007 by British entrepreneur Richard Branson. Branson pledged to award $25 million to anyone who can develop a scheme for removing at least one billion tonnes of the gas from the atmosphere every year, for a decade.
So, together with Klaus Lackner, a former colleague at Columbia University, Zeman devised a new way of scrubbing CO2 from air. He has also performed calculations, published in Environmental Science & Technology, which suggest that the new method is efficient enough to justify its use.
The process involves pumping air from the atmosphere through a chamber containing sodium hydroxide, which reacts with the CO2 to form sodium carbonate. This carbon-containing solution is then mixed with lime to precipitate powdered calcium carbonate – a naturally occurring form of which is limestone. Finally, the "limestone" is heated in a kiln releasing pure CO2 for storage.
If the kiln's heat came from a nuclear power plant then no fossil fuels would be needed to make this system work. But I would advice replacing existing coal, natural gas, and oil-powered electric power plants with nuclear power plants before using nuclear power to extract CO2 from the atmosphere.
The lower the cost of non-fossil fuels energy generation falls the more practical and affordable atmospheric CO2 extraction becomes. Nanotech replicators to build solar photovoltaics panels will some day make atmospheric CO2 extraction extremely cheap to do.
Few of the more than two dozen climate experts interviewed disagree with the one-meter projection. Some believe it could happen in 50 years, others say 100, and still others say 150.
Sea level rise is "the thing that I'm most concerned about as a scientist," says Benjamin Santer, a climate physicist at the Lawrence Livermore National Laboratory in California.
"We're going to get a meter and there's nothing we can do about it," said University of Victoria climatologist Andrew Weaver, a lead author of the February report from the Intergovernmental Panel on Climate Change in Paris. "It's going to happen no matter what - the question is when."
If you click through to the article you'll see what would get submerged along the US East and Gulf coasts by a 1 meter risk in the level of the ocean. But this claim by Andrew Weaver is a little annoying. We have the capability to put the entire planet into an Ice Age for cheap. There's nothing inevitable about global warming or the melting of glaciers on Greenland and the Antarctic continent.
Using either silicon dioxide or iron dumped in the ocean to produce dimethyl sulfide (DMS) we can make the Earth so cold that we bring on a new ice age. This can be done for a yearly cost of less than the United States wastes to subsidize corn ethanol production. For a few billion dollars per year we can turn much of the planet into an ice cube. For a smaller figure we could cancel out the amount of warming that might be caused by CO2 build-up.
One problem with this scheme: If we want to cancel out the effects of CO2 emissions then we have the problem of not really knowing how much an effect the CO2 is actually having. We do not know what the average global temperature would be in a given year minus the CO2 effect (or minus the effect of nitrous oxide or methane or other gases released by humans into the atmosphere). Still, presumably climate models will get better and in 20 or 30 years climate scientists create realistic simulations of Earth's climate with the ability to measure the effects of human intervention. Or we could just intervene by however much is necessary to ensure sea levels do not rise.
Suppose that the amount of CO2 already released into the air is already enough to raise temperatures at the poles enough to cause lots of water to flow into the oceans and raise water levels and flood low lying regions. Is that outcome so terrible that we should do climate engineering to prevent it from happening?
Should we do climate engineering to prevent the flooding Miami? Should we do climate engineering to prevent massive dislocations of humans in Bangladesh? Should we do climate engineering to prevent lots of high priced choice ocean front property from being destroyed by the waves and tides?
I'm thinking the world is going to run out of oil before some of the more pessimistic projections of carbon dioxide build-up can happen. So if we have a warming problem that'll cost us a lot of choice real estate (though while making colder places more livable and valuable to humans) then we could deal with that transitory trend toward warming by using climate engineering. On the other hand, we could instead opt to make the weather of Northern Europe, Siberia, Alaska, Canada, Minnesota and Maine more livable.
Extreme outcomes from fossil fuels burning are probably easily avoidable at low cost.. Ocean iron fertilization would cool the Earth by increasing natural sulfur aerosal production which would increase cloud formation and planetary reflectivity.
July 24, 2007 -- Prof. Oliver Wingenter of New Mexico Tech and his colleagues propose a limited iron fertilization of the Southern Ocean as a means to stimulate the natural sulfur cycle associated with marine phytoplankton which could result in increased cloud reflectivity that would slow down global warming and possibly decrease sea level rise.
Wingenter and his research colleagues Dr. Scott M. Elliot at Los Alamos National Laboratory and Prof. Donald R. Blake at University of California, Irvine report their research findings in an article published online July 18 in the journal Atmospheric Environment, titled "New Directions: Enhancing the natural sulfur cycle to slow global warming,".
The scientists base their plan on their observations made during the Southern Ocean Iron Experiments (SOFeX) research expedition, the longest and most comprehensive ocean iron fertilization experiment to date, which was carried out in 2002 aboard three research ships in the Southern Ocean, between New Zealand and Antarctica.
The scientists who conducted the SOFeX experiment were looking for a cheap way to cool the planet by pulling carbon dioxide out of the atmosphere. Instead they found a cheap way to pump a planet-cooling sulfide into the atmosphere.
Wingenter thinks we could delay global warming by 10 to 20 years at very low cost with iron fertilization of only 2% of the Southern Ocean. With just 30 ships and at most $100 million per year we could delay warming by 10 to 20 years.
"However, marine microorganisms not only consume inorganic carbon, but also produce and consume many climate-relevant organic gases," Wingenter continues. "The greatest climate effect of iron fertilization may be in enhancing dimethyl sulfide (DMS) production, leading to changes in the optical properties of the atmosphere and cooling of the region." Samples taken by Wingenter during SOFeX showed that the concentration of DMS increased about five times in the iron fertilized patch versus outside. Emissions of DMS are the main source of sulfate particle formation to the region and "seed" much of the cloud formation.
Wingenter and his research colleagues propose a limited fertilization of only about 2 percent of Southern Ocean---which would result in an estimated two degrees (Celsius) cooling of the region. A program of limited-scale iron fertilization in the Southern Ocean and perhaps a portion of the equatorial Pacific may have the potential to set back the tipping point of global warming from about 10 years to about 20 or more years," Wingenter estimates.
An iron-fertilization program of the scale envisioned by Wingenter and his fellow researchers would require about 30 ships, fertilizing the Southern Ocean with about 22 kilotons of iron sulfate, at an annual cost of anywhere between $10 million and $100 million, according to the article in Atmospheric Environment.
A program like this one could get tested at smaller scales and then scaled up very quickly as necessary. UC Irvine physicist Gregory Benford has proposed another cheap way to cool the planet as well. Cooling the planet down seems relatively easy. But I've yet to come across proposed engineering solutions for another consequence of atmospheric CO2 build-up: acidification of the oceans as atmospheric carbon dioxide dissolves into the oceans. What to do about that other than reduce CO2 emissions or accelerate the extraction of carbon from the atmosphere?
Writing in the Spring 2007 edition of the Wilson Quarterly scholar James R. Fleming argues that would-be climate engineers lack the ability to model all the side effects of climate engineering.
Yet thanks to remarkable advances in science and technology, from satellite sensors to enormously sophisticated global climate models, the fantasies of the weather and climate engineers have only grown. Now it is possible to tinker with scenarios in computer climate models—manipulating the solar inputs, for example, to demonstrate that artificially increased solar reflectivity will generate a cooling trend in the model.
But this is a far cry from conducting a practical global field experiment or operational program with proper data collection and analysis; full accounting for possible liabilities, unintended consequences, and litigation; and the necessary international support and approval. Lowell Wood blithely declares that if his proposal to turn the polar icecap into a planetary air conditioner were implemented and didn’t work, the process could be halted after a few years. He doesn’t mention what harm such a failure could cause in the meantime.
There are signs among the geoengineers of an overconfidence in technology as a solution of first resort. Many appear to possess a too-literal belief in progress that produces an anything-is-possible mentality, abetted by a basic misunderstanding of the nature of today’s climate models. The global climate system is a “massive, staggering beast,” as oceanographer Wallace Broecker describes it, with no simple set of controlling parameters. We are more than a long way from understanding how it works, much less the precise prediction and practical “control” of global climate.
Fleming also wonders who should control a climate engineering effort. The effects of climate engineering would create large numbers of both winners and losers. Cooling via engineering efforts would improve farming in some regions and make it much harder in other regions. Cooling would change costs of heating and air conditioning and air conditioning and change which structure designs are ideal in many areas.
Assume, for just a moment, that climate control were technically possible. Who would be given the authority to manage it? Who would have the wisdom to dispense drought, severe winters, or the effects of storms to some so that the rest of the planet could prosper? At what cost, economically, aesthetically, and in our moral relationship to nature, would we manipulate the climate?
But these questions which Fleming raises can already be raised about existing human activity. We build cities and cities cause severe thunderstorms. We plow fields on a massive scale to grow crops and farms reduce cloud cover and rainfall. In fact, humans might already have engineered the planet's climate thousands of years ago via farming and forest destruction that might have prevented an ice age. The difference with the modern would-be climate engineers isn't necessarily the scale on which they want to act. Rather, they want to intervene on purpose in a system to partially cancel out the effects of interventions we've already done by accident.
Given that our current industries, technologies, and lifestyles already generate lots of side effects and external costs (and not just due to climate effects) I do not see why we should oppose climate engineering just because it will inflict costs on some. If we took that approach on all environmental questions we'd have to abandon modern technology and force a huge contraction in the size of the human population. In many cases those costs will effectively come from returning a local environment to a state more like it would be absent human intervention. Though that would not always be the case.
Update: Climate cooling measures such as Gregory Benford and Oliver Wingenter propose can be implemented so quickly that we can wait to see whether global warming becomes a big problem before trying these methods. But it would be helpful to do research on these proposals to measure their effects and get a better handle on what undesirable side effects would arise from their use.
The best response I can see to rising CO2 levels is to try harder to develop cheaper substitutes to fossil fuels. Research that produces energy that is both cheaper and cleaner would give us the best of both worlds.
UC Irvine physics professor and science fiction writer Gregory Benford says climate engineering to prevent global warming would be cheap to do and could be done by private parties.
Benford has a proposal that possesses the advantages of being both one of the simplest planet-cooling technologies so far suggested and being initially testable in a local context. He suggests suspension of tiny, harmless particles (sized at one-third of a micron) at about 80,000 feet up in the stratosphere. These particles could be composed of diatomaceous earth. "That's silicon dioxide, which is chemically inert, cheap as earth, and readily crushable to the size we want," Benford says. This could initially be tested, he says, over the Arctic, where warming is already considerable and where few human beings live. Arctic atmospheric circulation patterns would mostly confine the deployed particles around the North Pole. An initial experiment could occur north of 70 degrees latitude, over the Arctic Sea and outside national boundaries. "The fact that such an experiment is reversible is just as important as the fact that it's regional," says Benford.
Benford says treating the Arctic would cost only $100 million per year.
"Anybody who thinks governments are suddenly going to leap into action is dreaming." Benford says that one of the advantages of his scheme is that it could be implemented unilaterally by private parties. "Applying these technologies in the Arctic zone or even over the whole planet would be so cheap that many private parties could do it on their own. That's really a dangerous idea because it suggests the primary actor in this drama will not be the nation-state anymore. You could do this for a hundred million bucks a year. You could do the whole planet for a couple of billion. That's amazingly cheap."
This proposal illustrates a larger pattern: Nation-states are becoming less important for major undertakings because scientists and engineers can find cheap ways to accomplish changes. For interventions whose bases of operations are easy to spot and stop this trend does not disempower nation-states. The governments will retain veto power. But for interventions that are harder to trace back to their perpetrators the loss of accountability could become very problematic for the human race.
Suppose the world heats up a few degrees Celsius and scientific knoweldge about climate advances to the point where scientists can state with certainty that human burning of fossil fuels is the major cause of this change. Then suppose some private group with enough money (or even a single rich guy) wants to put silicon dioxide over the Arctic or Antarctic in order to prevent gradual melting and rising sea levels. Would you support or oppose such a move?
Well, Danish climate scientist Henrik Svensmark argues that cosmic rays and not carbon dioxide build-up is the biggest cause of global warming.
Figure 5 takes the climate record back 300 years, using rates of beryllium-10 production in the atmosphere as long-accepted proxies for cosmic-ray intensities. The high level at AD 1700 corresponds with the Maunder Minimum (1645-1715) when sunspots were extremely scarce and the solar magnetic field was exceptionally weak. This coincided with the coldest phase of what historians of climate call the Little Ice Age (Eddy 1976). Also plain is the Dalton Minimum of the early 19th century, another cold phase. The wobbles and the overall trend seen in figure 5, between cold 1700 and warm 2000, are just a high-resolution view of a climate-related switch between high and low cosmic-ray counts, of a kind that has occurred repeatedly in the past.
Iciness in the North Atlantic, as registered by grit dropped on the ocean floor from drifting and melting ice, is a good example of the climate data now available. Gerard Bond of Columbia University and his colleagues showed that, over the past 12 000 years, there were many icy intervals like the Little Ice Age - eight to ten, depending on how you count the wiggles in the density of ice-rafted debris. These alternated with warm phases, of which the most recent were the Medieval Warm Period (roughly AD 900-1300) and the Modern Warm Period (since 1900). A comparison with variations in carbon-14 and beryllium-10 production showed excellent matches between high cosmic rays and cold climates, and low cosmic rays and the warm intervals (Bond et al. 2001).
Suppose scientists eventually confirm that increased cosmic rays from the sun increase cloud cover and cause cooling and that less cosmic rays are causing the world's current warming trend. Would you be any more or less inclined to support climate engineering to reverse natural warming caused by changes in the Sun's output?
In other words, if nature causes climate changes (whether cooling or warming) are we more or less justified in intervening in the climate than if we cause climate changes?
Suppose climate researchers discover 30 years hence that due to natural cycles the world is going to go through a long term cooling that will last centuries. Would you argue for generation of more green houses gases to counteract the cooling? Or would you argue that we shouldn't intervene in natural processes on such a large scale for our own benefit?
Update: I'm asking two underlying questions here:
I do not know whether the world will warm by much in the 21st century. I do not know whether we are experiencing more climate change due to human intervention or due to natural phenomena. I'm not trying to argue the global warming skeptic or the global warming believer position. I'm trying to find out how much of the support for a reduction in CO2 emissions is due to the known (clearly human) causes of those emissions or the theorized effects of those emissions.
Update II: For those who do not read me regularly, here are several things I believe about the future of energy technology and climate:
My guess is that if global warming becomes a big problem we will use cheap ways to cool down at least parts of the planet. The good news is that if we reach that point the cooling down will be cheap to do. So the nightmare scenarios for warming are unlikely to ever happen.
Nobel Prize winning chemist Paul Crutzen says we could cool the planet by injecting sulfur into the atmosphere.
Injecting sulfur into the atmosphere to slow down global warming is worthy of serious consideration, according to Nobel laureate Paul Crutzen from the Max Planck Institute for Chemistry in Germany and the Scripps Institution of Oceanography, University of California at San Diego. His thought-provoking paper1 is published in the August issue of the Springer journal Climatic Change, devoted this month to the controversial field of geoengineering.
The sulfur would reflect light back into space.
Crutzen’s proposed planet-saving scheme, which artificially injects sulfur into the earth’s stratosphere (the second atmospheric layer closest to earth) to offset greenhouse gas warming, is based on this phenomenon.
His “albedo2 enhancement method”, or, in other words, his proposed way of increasing the earth’s reflective powers so that a significant proportion of solar radiation is reflected back into space, aims to replicate the cooling effect these man-made sulfate particles achieve.
If we get into desperate straits sulfur could be used as an emergency climate treatment. It would require continuous application since the sulfur does not stay in the atmosphere.
In Crutzen’s experiment, artificially enhancing earth’s reflective powers would be achieved by carrying sulfur into the stratosphere on balloons, using artillery guns to release it. In contrast to the slowly developing effects of global warming associated with man-made carbon dioxide emissions, the climatic response of the albedo enhancement method could theoretically start taking effect within six months. The reflective particles could remain in the stratosphere for up to two years.
Would the sulfur cause acidic rains or other problems? How big would those problems be? Volcanoes inject large amounts of sulfur. What other effects does that sulfur cause?
On most issues involving fears of worst case outcomes of human activity my take on them is that we can use technology to prevent or reverse the outcomes. That's not an argument for total complacency. But it is an argument against claiming that civilization is going to collapse or that we are going to suffer terribly.
The best way to cut carbon dioxide emissions is to develop cleaner energy technologies that are cheaper than the dirtier ones. Then we'd get both cheaper energy and a cleaner environment.
James Pearson, John Oldson and Eugene Levin of Star Technology and Research in Mount Pleasant South Carolina propose construction of a system of satellites to control the amount of sunlight that reaches and warms Earth.
A wild idea to combat global warming suggests creating an artificial ring of small particles or spacecrafts around Earth to shade the tropics and moderate climate extremes.
There would be side effects, proponents admit. An effective sunlight-scattering particle ring would illuminate our night sky as much as the full Moon, for example.
And the price tag would knock the socks off even a big-budget agency like NASA: $6 trillion to $200 trillion for the particle approach. Deploying tiny spacecraft would come at a relative bargain: a mere $500 billion tops.
But the idea, detailed today in the online version of the journal Acta Astronautica, illustrates that climate change can be battled with new technologies, according to one scientist not involved in the new work.
Social anthropologist Benny Peiser of the British Liverpool John Moores University says this proposal demonstrates humans can prevent disastrous climate changes.
"I don't think that the modest warming trend we are currently experiencing poses any significant or long-term threat," Peiser told LiveScience. "Nevertheless, what the paper does show quite impressively is that our hyper-complex civilization is theoretically and technologically capable of dealing with any significant climate change we may potentially face in the future."
Here is the abstract to the research paper. The particle solution is too expensive but the ring of controlled satellites could be implemented for at most a half trillion US dollars.
An artificial planetary ring about the Earth, composed of passive particles or controlled spacecraft with parasols, is proposed to reduce global warming. A flat ring from 1.2 to 1.6 Earth radii would shade mainly the tropics, moderating climate extremes, and counteract global warming. A preliminary design of the ring is developed, and a one-dimensional climate model is used to evaluate its performance. Earth, lunar, and asteroidal material sources are compared to determine the costs of the particle ring and the spacecraft ring. Environmental concerns and effects on existing satellites in Earth orbit are addressed. The particle ring endangers LEO satellites, is limited to cooling only, and lights the night many times as bright as the full moon. It would cost an estimated $6–200 trillion. The ring of controlled satellites with reflectors has other attractive uses, and would cost an estimated $125–500 billion.
Satellites with reflectors could rotate to present more or less reflective surfaces toward the Sun. Also, a fancier design to such satellites could allow them to also function as communications or remote sensing satellites. One could even imagine adjusting the orientation of some of the satellites to reflect more light onto crops to make them grow more rapidly.
Whether global warming ever becomes a big enough problem to justify a climate engineering project remains to be seen. Many would see such a project as an intervention in nature that humans have no right to make. Some would claim that climate engineering amounts to "playing God". Also, such a project would inevitably change climate in some parts of the world in ways that residents of those parts would see as detrimental. However, should humans ever colonize Mars I expect proposals for climate engineering of Mars to meet far less resistance on ideological or consequential grounds. Mars is so inhospitable to human habitation that the debate would center around what is the best way to adjust Mars to human needs. There'd be no fear of making some parts of Mars worse for humans in order to make other parts better. Also, nature as we understand it with a large range species does not exist on Mars. So the threat to Martian lifeforms (if any still exist) would be small as compared how climate engineering on Earth would inevitably shrink some ecological niches while expanding others.
I am not a pessimist about global warming for the simple reason that humans are going to become orders of magnitude more technologically capable in the 21st century. All problems will become more solvable. I think it unlikely humans will have much need for fossil fuels 50 years from now. Other energy technologies will become more attractive long before significant global warming takes place.