May 21, 2011
End Of World In 1 Billion Years?
Apocalypse Not Yet. You notice any new signs of the end of the world today? I have to say I got distracted and missed paying attention at the moment when it was all supposed to end. My neighborhood is quiet and peaceful. But religious belief is not the only source of predictions of the end of the world. A pair of astronomers say in about 1 billion years the output of our Sun will go up enough to evaporate the oceans and rivers into water vapor.
The story begins some 4.57 billion years ago, when the young sun's nuclear furnace ignited and stabilized. Back then, solar physicists estimate, the sun was 30 percent dimmer than it is today. As it has matured, it has brightened at a pace of about 1 percent every 110 million years.
Over that period, the two explain, Earth's climate system has adjusted to the increase in the sun's output, keeping the planet's average temperature within a livable range and with plenty of water on hand. Orbiting 93 million miles from the sun, Earth finds itself nicely placed in the sun's habitable zone.
But over the next billion years, the duo says, the sun's output will rise by another 10 percent.
Let us suppose sentient beings will still inhabit planet Earth hundreds of millions of years from now and beyond. What to do? I see a few choices:
- Migrate to Mars.
- Do climate engineering
- Move Earth to a larger orbit (and thereby lengthen bond maturities too).
- Leave the solar system.
Mars? It is a smaller planet with far less water and oxygen. Earth is really superior for our needs. So why give up Earth if it isn't necessary?
Climate engineering? Okay, I'm not opposed on principle. But one problem: It will require constant attention. What if wars or phases of extreme global ennui leave us unable or unwilling to maintain satellites that reflect some of the Sun's rays? Plus, climate engineering can't go the whole distance as the billions of years go by and the Sun swells out as a red giant and expands to Earth's orbit.
Move Earth? A very doable endeavor with an asteroid that swings by Earth and Jupiter once every 6000 years. A small amount of Jupiter's rotational motion would be transferred to Earth in very small increments.
So clearly moving Earth is the best solution which will last the most number of years.
But what about leaving the solar system to go to a younger star? Can we hope to do this with known laws of physics? We'd need fusion reactors as power sources just to maintain habitats. The trip would take an extremely long time. I think we need to be lucky and find that the universe has additional physical laws that make this easy.
Another thought: Move between universes. But most the places we'd come out at in another universe would likely be empty space. How to find a habitable planet in a parallel universe?
I think humans will be lucky if they survive the coming 100,000 ice age.
LOL @ Bruce
All this speculation is perhaps amusing if it wasn't so unlikely to be accurate. Hathaway, supposedly the premier solar activity guru, predicted that solar cycle 24 (the current cycle) would be much more active than cycle 23. 2 years later, after a total solar zero fizzle, he admitted defeat and started predicting lower and lower peaks.
Just like climate scientists, weathermen, and economic cycle touts, they very rarely get ANY sort of prediction correct.
Since the average longevity of any species on earth is 1 million years, we probably won't be around to verify this inane billion year prediction in any case, LOL, and that's MY prediction.
By then, (If we're still around.) we'll have long since built a shell around the Sun to tap it's full power output. We won't have to do anything, as the Earth and other remaining planets won't be directly illuminated by sunlight, they'll be the targets for spotlights mounted on that shell. Probably with a spectrum rather different from natural sunlight, to maximize available photosynthetic energy for a given heat load.
You have way too much time on your hands. Speculating about humanity's situation one hundred years from now, as Michio Kaku does in "Physics of the Future: How Science Will Shape Human Destiny and Our Daily Lives by the Year 2100", is hard enough.
This interglacial will end BioBob. They always do. The ice sheets will be a mile thick over the major wheat growing regions in the world. Billions will starve.
The Eemian (the integlacial before ours) ended in as little as 400 years.
"The recent high-resolution Atlantic sediment record of Adkins et al (1997) suggests that the move from interglacial to much colder-than-present glacial conditions occurred over a period of less than 400 years (with the limitations on the resolution of the sediment record leaving open the possibility that the change was in fact very much more rapid than this)."
Just an off-the-cuff calculation, but:
- blackbody radiated power goes up as the fourth power of temperature
- the fourth root of 1.1 is approximately 1.025
- 1.025 * 300 kelvin is 307.5 kelvin
- raising global temperature from ~27 C to ~34 C isn't in itself enough to boil the oceans, not by a long shot.
Unless they postulate runaway greenhouse effect from an ~8 C global temperature rise, I don't really see this being a valid scenario. We have ~2 C right now due to carbon forcing and runaway doesn't appear to be even remotely likely; nevermind past records of substantially higher temperatures than that.
Tether a solar sail to both of earth's poles.Over a period of time earth's orbit can be moved away from the sun.No problem.
Dentin, what they are presuming will happen is the upper atmosphere will warm up enough to increase water loss. At the moment water water generally freezes out before it gets too high, but it seems likely that if the sun increases its output enough a substantial amount of water vapour could make it into the upper atmosphere where the hydrogen component could escape into space, resulting in the earth getting drier and presumably more oxygen rich.
And Bruce, we've had plenty of experience at warming the earth and we weren't even doing that on purpose, so an interglacial doesn't seem that scary. It's been suggested that if we take out the Antartic icecap we could make the earth interglacial free, although I understand there are some drawbacks to melting a more than kilometer thick continent sized icecap.
Of course, neither heat or cold on earth will matter much to us once our robot overlords exile us to Chiron Beta Prime.
I wrote interglacial? I meant glacial period. Sorry about that. I need more sleep. Or brain rejuvenation technology.
Ronald, I doubt we've warmed the earth at all. Looking the ice cores, the MWP was warmer than now, the Roman Optimum was warmer than MWP, and Minoan warmer than Roman, all on a 1000 cycle. What some perceive as man made warming is just the cycle.
Yet again, it is necessary to caution against extrapolation from the status quo.
Humans as Homo sapiens will not exist in even 1000 years, when we shall be on our nth auto-redesign.
Our imaginations are insufficient to the task of imagining the Earth in a billion years, much less the place on it (in it?) occupied by whichever of our descendants choose to remain on the motherworld.
That will be awesome in the true sense of the word.
Bruce, ice cores don't record temperature.
RE: If It's Not One Thing, It's Another....
In one billion years, our galaxy will begin a collision with the Andromeda galaxy. The collision will take about a half-billion years to complete. And our solar system will probably be made something of a hash in the process: bombarded by stray planetary—if not stellar—objects, e.g., When Worlds Collide, and/or hurled into the vast inky blackness of the inter-galactic void.
P.S. Who knows.....
....maybe by then, we'll have become something like the Vorlons.....
How long will it be before the southern wanderer moves off the South Pole? It is my understanding that the current glaciation period will end when both poles are free of a large land mass.
If the sun's output increases by 10% in that time, it may be Waikiki Beach everywhwere!
Of course, the beneficiaries will likely be the rat, who will occupy our ecological niche after we have gone the way of the dinosaurs.
If you accept coordinated stasis as the best explanation for evolution and extinction, then we've got about 1-2 million years left as a species.
Brett and Baird have documented some eight successive faunas of marine invertebrates in the Appalachian Basin of the Middle Paleozoic.
Marine invertebrate pattern: about 20% survive after each major extinction.Each fauna survives an average of 5-7 million years.
Ranging from only a few dozen known species to the 300 or more known from the Middle Devonian sequence mentioned above, most of the component species are present at the very beginning of the sequence.
Most persist unchanged throughout the sequence, but then, abruptly, most disappear.
Only, on average, 20% of the species manage to survive to the next successive faunal interval.
The new species that comprise the next succeeding marine regional system are either newly evolved or migrate in from adjacent regions.
This would be very simple to work around, all our descendants would need to do is to put some kind of occulter into orbit between the earth and the sun to reduce the amount of light reaching the earth from the sun. Come on, Mr. Burns thought of this and so did Professor Chaos. Of course this only buys a billion or so more years. Eventually the sun will destroy the earth and there is probably nothing even our most advanced descendants can do about it, except move somewhere else.
Eh, from what I read it's only 500 million years before the Sun's brightening moves the inside edge of the habitable zone past Earth's orbit.
Of course, an extinction level impact is due way before then. But we're now on the look out for those, with enough warning we can avert them. As long as we don't lose our technology.
Since we can't change the Sun's evolution, we only have three way we can adapt to the inevitable stellar brightening:
1. shade the Earth
2. Move the Earth to a further orbit.
3. Leave for someplace else (of which, terraforming Mars is a subset)
Moving the Earth is the wrong answer. If your lightbulb is too bright, you don't go sit in the corner where it's darker, you install a dimmer switch and turn the light down. Slightly altering the fusion reaction in the sun to reduce its output would be easier than rearranging the planets.
If we store the genomes (and epigenomes?) of a representative, diverse sample of each species, it could be restored.
Anyway, there will be no shortage of species. In fact, the earth will be glutted with new species making ecological niches of each other, once I crank up my Apple iGod Biogenerator in a few years. I'll set it on auto-generate, and thousands of new species will crawl and fly from my deck every day. (I advise you not to be my neighbor.)
"We have ~2 C right now due to carbon forcing"
I'll put up $100.00 to bet that, no, we don't.
And if you want to contact me about that, remove the numbers from email@example.com, subject line CO2bet
I am reminded of an old joke:
The world famous astronomer is giving a public lecture about the life and death of the sun. Near the end of his lecture, he said, "The best theories we have predict that the sun will most likely explode in about one billion years."
At this, a member of the audience jumped up shouting, panicky and in near hysteria, "What?!!??!? What, did you say, the sun will explode?!?!???"
The astronomer replied, "No, I said the sun will explode in one billion years."
"Oh, thank God. Whew, I thought you said a million years. Never mind."
@Bruce, One good thing about your prediction is that it is somewhat more likely than anything out at one billion years.
But that does not make it any more accurate than a week-next-Thursday's weather forecast, which is either 100% wrong or 100% right. If any glacial epoch does start (I agree that if the past is any indicator of the future, then it is likely) and only lasts 59 thousand years is your apparent prediction of 100,000 years duration 100% correct or 100% wrong ?
@Ronald, yes, scientists theorize that oxygen/other isotope ratios in the layers of ice-core samples can be used to describe past temperatures, as Bruce mentioned as a "Proxy". There are troubling accuracy issues in performing this analysis, and while perhaps useful, ultimately these proxies may be wildly inaccurate or useless.
The last two sentences in the paper are well worth the wait.
I have no idea how they would accomplish it, but if we actually have descendants a billion years from now then this sort of problem will be child's play to them.
if we actually have descendants a billion years from now then this sort of problem will be child's play to them.
Kinda like our mastery of the federal budget after 200 whole years of trying, in other words.
* Migrate to Mars.
* Do climate engineering
* Move Earth to a larger orbit (and thereby lengthen bond maturities too).
* Leave the solar system.
You forgot trans-humanism. Probably it's cake too.
Kinda like our mastery of the federal budget after 200 whole years of trying, in other words.
The whole problem is that we're *not* actually trying.
RE: Migrating to Mars. I suspect that on this time scale, Mars will have long since been disassembled. The Earth too, probably. Allowing valuable matter to sit around in a form that minimizes habitable surface area while simultaneously placing it at the bottom of an inconvenient gravity well is no way for an advanced intelligence to run a stellar system.
BioBob, proxies can be used to indirectly reconstruct temperature, but as you mention accuracy can be a problem, particularly for some proxies.
Bruce, an important ice core proxy for temperature is CO2 concentration. So if you are going to argue that CO2 concentration doesn't affect temperature, which I assume you are, and you are using ice core proxies to do that, you'll need to explain just how that works.
But on the other hand, you actually don't need to explain how that works. The issue is not whether or not temperatures have varied in the past (they have), but whether or not human activity, particularly in the last 100 years or so, has warmed the earth. If one is to argue that human activity is not warming the earth, then one I think one would have to believe one or both of the following.
1...CO2 is not a greenhouse gas.
2...Human activity has not increased the concentration of CO2 in the atmosphere.
Do you believe either of the above, Bruce?
Ronald, the Vostok ice core during the Eemian (interglacial before ours) is quite informative.
CO2 (in pink) followed the rise in temperature (blue) and no humans were contributing any significant CO2 -- other than breathing and burning wood.
Yet ... the temperature rose 12C and CO2 rose from 190ppm to 290ppm.
I would conclude that whatever warmed the earth caused more CO2 to be out gassed and/or more vegetation produced more CO2.
CO2 was not the cause of the Eemian and Co2 did not prevent the Eemian from ending.
I doubt CO2 caused the Holocene and won't prevent the Holocene from ending.
Think of this way ... a cold coke holds more CO2 than a warm coke. More vegetation means more CO2. If it gets warmer, the oceans hold less CO2 and more plantlife means more Co2.
The theory by paleoclimatologists on CO2 and warming is that some smaller push (e.g. change in Earth's orientation toward the Sun) starts the warming, makes the oceans warm enough to give up some CO2 (warm liquids dissolve less gas), and also as the ice retreats more dark plant matter absorbs more CO2. A feedback cycle keeps the warming in action. I may be missing some details as I haven't read this in a while. But that is the gist of it.
Sorry, Randall, but most data, such as it is, shows the exact opposite. The ambient temperatures rise and sometimes 400-1000 years later the CO2 concentration rises --- but sometimes CO2 doesn't rise after temperatures do. Sometimes the atmospheric CO2 concentration rises to 2000 ppm or more and then there is an Ice Age. Clueless !
The fact is that we only GUESS at what the atmospheric concentrations were thru proxies and what the concurrent temperatures were thru other proxies. Nobody was around to use a thermometer more than 200 years ago and scientists blithely talk about temps millions of years ago. This is ALL guesswork without any kind of high probability of accuracy. The other facts are that even with thermometers, we can not get accuracy of temperatures for any sizable portion of the globe larger than that of measurement error. Do you understand what that means? Our measurement error is larger than ANY measured average change in temperature over ANY sizable portion of the globe. In short, we suck, and this global warming crap is all a kabuki show.
We are babes in the woods - while we make progress, we are pretty ignorant about what ACTUALLY causes these kinds of cycles at the moment.
Consider it a procession of pixies proposing processes of purloined proxies. LOL
@ Ronald - lol - you don't understand what proxy means do you? "BioBob, proxies can be used to indirectly reconstruct temperature" equals BioBob, proxies can be used to proxy proxy temperatures"
Bruce doesn't need to believe anything. Those who assume that humans are increasing atmospheric CO2 concentrations (possibly demonstrated by inference but not proven, since correlation does not equal causation) need to prove that fact but can not. Those who assume that the small increases in CO2 concentrations resulted in atmospheric warming must prove THEIR assertion, but they can NOT. Bruce merely points out that their assertions are flawed and remain simply assertions without sufficient proofs.
end of story, a nice piece of theater.
Bruce, I'm still not clear on what you think. Do you think that CO2 is a greenhouse gas?
BioBob, do you believe summer is warmer than winter?
Ronald, I think H2O is the most powerful GHG.
In theory CO2 is a GHG ... but it seems to have had little effect in the Eemian.
"The consumption of terrestrial vegetation by animals and by microbes (rotting, in other words) emits about 220 gigatonnes of CO2 every year, while respiration by vegetation emits another 220 Gt. These huge amounts are balanced by the 440 Gt of carbon dioxide absorbed from the atmosphere each year as land plants photosynthesise.
Similarly, parts of the oceans release about 330 Gt of CO2 per year, depending on temperature and rates of photosynthesis by phytoplankton, but other parts usually soak up just as much - and are now soaking up slightly more."
770gt natural versus 26 by burning fossil fuels.
The question is ... how can anyone claim with a straight face that the planet can only deal with EXACTLY 770gt of carbon ... and can't deal with an extra 3%?
Looking at the Eemian data I would surmise that the real problem is that natural warming has resulted in more natural CO2 staying in the atmosphere.
LOL @ Ronald
Somebody's summer in the Klondike is colder than somebody's winter in Jamaica. Don't ask stupid questions and you won't get stupid answers.
At the tone, the average temperature of earth will be 23.45 degrees centigrade --- beep ---- ROFL /sarc
There is nothing more absurd than a "scientist" claiming an certain average global temperature "anomaly" of less than 1 degree to a 'precision' of a tenth (or more) of a degree when the instruments used to measure the constituent values are at best accurate to +/- two (2) degrees and the experimental design // data collection has close to zero replicability and reliability.
Garbage IN Garbage OUT
Bruce, CO2 isn't a greenhouse gas just in theory. If infrared light in shone through a tube of CO2 it will heat up more than if the same light is shone through a tube of plain air. Do you accept that CO2 does absorb certain wavelengths of infrared radiation?
And do you accept that by slightly increasing the amount of CO2 in the atmosphere year by year, human activity has increased the amount of CO2 in the atmosphere by about a third over the past 200 years? If not, where did the CO2 released by burning fossil fuels go?
But there is so little of it Ronald.
There is something like 8000 times as much H2O in the atmosphere as there is CO2 (lets ignore the oceans for a moment). There is very little potential for Co2 to hold much heat.
Deserts, for example, can cool off by 40C from day to night because there is little water vapor. Jungles rarely cool off at night comparitivley.
"And do you accept that by slightly increasing the amount of CO2 in the atmosphere year by year, human activity has increased the amount of CO2 in the atmosphere by about a third over the past 200 years?"
No. I believe the opposite. Warming after the LIA made the oceans less capable of holding onto the dissolved CO2.
If you raise the temperature of water 1C, it can hold 59ppm Co2 less. That accounts for a lot of Co2.
"If not, where did the CO2 released by burning fossil fuels go?"
The oceans and plants absorbed just like they absorb the other 97% of natural Co2.
And then we could get into the increase in bright sunshine over the 20th century ...
Bruce, the atmosphere isn't over 300% water vapour.
BioBob, would you say that it is impossible to determine if February is hotter than April in Cairns in Australia, as thermometers say the difference is less than 2 degrees?
Ronald, which station record and which year? for which location, time of day, and which set of equipment ? all have changed since a particular measurement station opened and the environment of the station has also changed eg "Cairns Aero" since the airport has been upgraded several times and urban heat island effects have changed since the population etc has changed as well. None to few of the effects of these alterations have been tested or baselined on their effects on the records kept since 1942. There is no way to determine the relative accuracy of 1945 data versus 2010 data as a result of these issues. But certainly the YAHOOS generate daily max-mins, averages, and then generate monthly averages, etc etc all of which signify nothing much at all, but they serve as a flashy proxy for the actual temperatures at one linear-sequence-point-in-space-time that has nothing much to do with any adjacent equivalent, since those weren't "measured" at all.
Cairns Aero Number: 31011 Opened: 1941 http://www.bom.gov.au/jsp/ncc/cdio/weatherData/av?p_nccObsCode=122&p_display_type=dailyDataFile&p_startYear=1942&p_c=-199118277&p_stn_num=031011
I would say that YES, it is impossible to answer that question with any accuracy or high probability of accuracy for the approximately 4.5 billion years before 1942. One could argue that the question concerning probabilities concerning "Cairns Aero" station could be determined for a particular year or as a probability for a range of years, but this may have little to do with the question a few kilometers away or on any particular future day/time during those periods.
See that's the problem with temperature. It changes continuously; its hard to measure over time; the method of measurement changes the numbers, etc. It isn't simple. The more carefully you examine the issue, the more cans of worms you step into.
Ok. Bad googling. I should have done my own math.
Up to 4% of the atmosphere can be water vapor over oceans and almost zero over desert.
4% = 40,000ppm = 110x as much, not 8000.
However the average is lower.
Bruce, the oceans are currently a net sink of CO2. You say that there is so little CO2. Do you accept that current CO2 concentrations are around 0.39% and that level has increased by over a third in the past 200 years?
Oh dear, I'm making mistakes again. I meant to type, do you accept that current CO2 concentrations are around 0.039%, not 0.39%. Sorry about that.
BioBob, so I take it you do think it is possible to determine if February is hotter than April in Cairns using thermometers?
"Bruce, the oceans are currently a net sink of CO2."
That concept intrigues me.
If they were a net sink 100 years ago and are still a net sink, then there must have been room for more Co2 so why do they claim Co2 in the atmosphere going up?
If the oceans are warming they should have less capability of taking in more Co2.
I try and find out, but this is the best I could find: "The rough calculation of CO2 solubility shows that about 59 ppm CO2 will be released as water is warmed ONE degree from 13 to 14 deg C."
Then there is this:
"Wind blowing on the ocean is a crucial factor mixing the greenhouse gas carbon dioxide into the ocean depths and keeping it from going back into the atmosphere."
"Right now, for instance, the oceans absorb about 30 percent of the carbon dioxide released into the atmosphere."
And then this : "However, a recent paper by Wolfgang Knorr indicates that the fraction of CO2 absorbed by carbon sinks has not changed since 1850"
How is it possible that oceans know to take an exact fraction of Co2?
And if the oceans always take the same fraction, that implies they can always absorb more Co2 ... but if the oceans are warming they should be able to absorb less Co2.
But then again, recent evidence from Argo suggests oceans are colling meaning they could take more CO2 in.
Too complex to be definitive.
Ronald, anything is possible but the probability is always in question. The issues I already raised remain in play and you have not resolved them.
I almost certainly can find one particular February temperature reading COLDER OR WARMER than one particular April reading since I have 70 years worth of "observations" to cherry pick. However, it would seem that it would have no real significance in any case.
But feel free to make your intended point.
Bruce, CO2 levels in the atmosphere have increased over the past few centuries. This has resulted in CO2 moving from the atmosphere into the oceans as they move towards equilibrium. If CO2 concentrations in the atmosphere had instead decreased then the oceans would have released CO2 as it moved towards equilibrium with the atmosphere. Increased atmospheric CO2 concentrations are the main component of anthropogenic global warming. Do you accept that CO2 levels in the atmosphere have increased by a third or more in the past couple of hundred years?
BioBob, my point is that you appear to be saying that we are unable to tell if February is hotter than April in Cairns using thermometers.
Ronald, that is essentially correct. I am saying that any claim of accuracy for a particular temp in Feb or a particular temp in April is equally absurd given the difficulties and realities involved with what you are actually measuring and how you are actually measuring it.
If you want to make a claim about the relative temperatures of an area in space in two instants of time, you damn well want to design your methods and materials better than sticking one box next to an asphalt airport runway where it is irregularly fumigated with jet exhaust and taking readings at f*ckall times of days whenever you remember to do it, without recalibrating your instrument regularly, and moving the instrument to a new spot without determining the effects of that move, etc etc.
Yep. Now if you were to locate a random stratified sampling grid (in an area unaffected by confounding human contaminating inputs) of several (hundred) identical regularly calibrated thermometers, which adequately sampled that grids variability, with identical recording accuracy and method, and then documented the nature of the variability of that stratified grid over a significant amount of time without bollocking the experimental design, I would entertain your conclusions concerning the probability of one time unit being warmer or colder than another. But they don't even come close.
It's not science - it's garbage.
Ronald, the same thing could be said about the Co2 in the Eemian ... except for the "anthropogenic " part.
Try to remember what the Greendland Ice Core data shows.
The cooling from the height of the MWP to the depths of the LIA happened without a change in CO2.
We still haven't gotten as warm as the MWP and we won't see the warmth of the Roman Optimum or Minoan Warming every again in the Holocene. Both the MWP and RO and Minoan occurred without CO2 changes.
BioBob, do you think all thermometers are inaccurate? For example, when a doctor takes somebody's temperature and gets a reading of 37 degrees, do you think there is at least a 15.8% chance the patient has hypothermia?
Bruce, there are a couple of things I'd like to be clear on as there doesn't seem much point in discussing CO2 levels 130,000 to 140,000 years ago if we don't agree on CO2 levels over the past couple of hundred years. Do you agree with me that the level of CO2 in the atmosphere has increased by a third or more in the past 200 years?
Ronald, CO2 levels don't seem to effect temperature. It seems to be the other way around. You seem to think CO2 created by man to be some sort of magic gas that can make CO2 behave differently than it has in the past.
Yet temperature has gone up and down without CO2 rising before the temperature, even during the Holocene.
The ice core data shows us still cooler than the MWP. CO2 seems quite weak if it has any effect at all.
Okay Bruce, so you are saying that CO2 is not a greenhouse gas. And you say this because changes in temperature have not always been matched by changes in CO2 concentration. This would be a problem if one believed that CO2 was the only influence on earth's temperature. Do you know of any climatolgist who thinks that CO2 is the only influence on the earth's temperature? Or anyone at all who thinks this, high school coach or whatever?
Ronald, 1st you must understand that temperature is an instantaneous measure of constantly changing kinetic energy or heat in a substance and all commonly used instruments which provide temperature readings only provide a proxy of that value.
When you try to 'estimate' temperature, there is instrument error, precision, and accuracy. Different temperature recording instruments all have different values for these three parameters, but scientists attempt to minimize this type of error by something called calibration. Frequent calibration is required for temperature recording equipment, but this is too often skipped or delayed due to it's expense. Mercury thermometers may be accurate to plus or minus 1 degree F, and if so, any difference in temperatures 2 degrees or less can not be said to be significant because they are less than the measurement error. Less/erroneous calibration equals a larger instrument error.
Second there is something called observational error, which is the difference between the 'real' value and that measured. This is comprised of systematic error and random error. Systematic error could be something simple like always reading a mercury in glass thermometer by looking down at he meniscus rather than always level with it or increasing instrument drift for resistance devices. Random error can be measured by statistical techniques like the central limit theorem, but require multiple measurements at a single time, and/or a statistically significant sample size. Taking one measurement at a time means that you can not correct for random errors. Systematic error is more difficult to correct or even discover.
Lastly, you can have sampling error. A particular temperature measurement in a particular spot theoretically varies around a mean in the form of a normal curve. In order to know the variance of that normal curve, you need a statistically valid sample of that normal curve. You can not know that value if you take one measurement, nor can you know where in that distribution your measurement falls.
Since ALL of these errors, and likely others as well, are present in the Cairns data, we know that the measurements can not be accurate but we can not know how inaccurate they are.
Simple in concept but exceeding complex in execution. This cautionary applies to any temperature recording schema. Garbage IN equals Garbage OUT. If you want to get accurate and known readings you must DO THE WORK REQUIRED TO GET THEM. Further, you must design your sampling scheme to fit the type of data you need and the conclusions you wish to draw.
In order to conclude that Feb is never, always, sometimes, hotter than April in Cairns, you must know alot about the population of temperatures in those months and of the area called Cairns, so that you may say that your recorded temperatures are significantly different at the precision you require, perhaps the 2 degrees you 1st mentioned. One max-min thermometer at the Cairns airport won't cut it. LOL
"And you say this because changes in temperature have not always been matched by changes in CO2 concentration. "
I'm pretty sure NEVER in the last 500,000 to 1,000,000 years according to ice core data.
"Do you know of any climatolgist who thinks that CO2 is the only influence on the earth's temperature?"
Which major climate scientists emphasize that other climate factors have changed int he 20th century?
CO2 is like their god ... and they worship it and forsake other gods.
Which climatologists mention sunshine hours having changed? (There two papers by Martin Wild surveying the world, but he doesn't get any press)
Pick UK, Sunshine, Annual.
The 1971-2000 average was 1350 hours. The smoothed kernel filter value has 2010 at 1430 hours. And 1929 at 1340.
80 hours above the 1971-2000 average = 5.9%
90 hours above the 1929 average = 6.7%
The CET graph (bottom of page) shows a similar rise.
“There is an overall increasing trend in the number of
bright sunshine hours, amounting to about 100 h in
the last 100 years (0.96 h/year), which represents an
increase in bright sunshine hours of about 4% in a
Greater Alpine Region:
17 - 29%
"The recent trends in winter precipitation have been accompanied by respective trends in sunshine (significant increase in all subregions of 17 to 29%)"
"During the 20th century SS in Japan increased by 10%."
BioBob, the points you mention above would apply to thermometers used by health professionals, so with your previously mentioned margin of error of at best +/- two degrees, do you think that there is a 45% or greater chance that a patient with a measured temperature of 37 degrees has either hypothermia or hyperthermia?
Bruce, are you saying that temperatures and CO2 concentrations haven't both increased in recent history? Because I'm pretty sure now counts as being within the past 500,000 to 1,000,000 years.
Ronald, Can you find a historical time when CO2 led temperature climbs?
I'm saying CO2 did not cause temperatures to go up. Or down. The LIA occurred without Co2 changes ... and maybe despite CO2 changes.
According to the ice core graphs temperatures at the beginning of the Holocene went up 10C or more without a change in Co2.
And the Minoan Warming (3C warmer than today), Roman (2C warmer) and MWP (1C warmer) all occurred without a change in Co2.
The temperature went to slow in the 1970s scientists thought an ice age was coming ... even while CO2 was going up.
Bruce, the climate record supports CO2 being a greenhouse gas, but not it being the only influence on global tempertures. CO2 did not trigger interglacial warmings, but it reinforced them. Changes in the distribution of insolation triggered them. Can you see how CO2 does not have to trigger interglacial warming to be a greenhouse gas? And you might want to check the ice core data you are using. Ice cores indicate temperatures did not change 10 degrees at the start of the holocene without a change in CO2 and there was no Minoan Warm Period, Roman Warm Period, or Medieval Warm Period with global temperatures higher than today.
Ronald, there is a pretty big difference between an individual 100-300 lbs of a endothermic bag of water (a human) and 488 square kilometers of earth surface (the area of Cairns) wouldn't you agree ? And that need not even include that area's 3rd dimension (vertical).
However, for argument's sake, I would say that there is a significant temperature difference between a human's fingertip epidermis than that particular human's internal organs at any particular instant in time. For that matter, human body temperature follows a diurnal pattern in any particular individual and is not necessarily the same in two different individuals. You seem to be feverish, LOL.
37 degrees in Fahrenheit or Kelvin would not be hypothermia in a human - it would be post-mortem, rofl. Use the proper scale abbreviation at least, dude. I assume you meant 37 C. At any rate 98.6 deg F or 37 C is an average, or a mean on a normal curve of all possible normal human internal body temperatures. This variability has been extensively studied in very well designed and executed experiments with statistically valid results, normally distributed with a mean of 98.2 F and a standard deviation of 0.62 in humans in good health. At least the Doctors and researchers studying human body temperatures generally calibrate their instruments, consistently observe the temperature performance, and generally follow best practices for the science they undertake. eg https://secure.wikimedia.org/wikibooks/en/wiki/Introduction_to_Medical_Statistics/Analysis_of_a_single_sample
The temperature of Cairns is what I conclude is a f*ckall number, since there is crap for pretty much anything to do with that number, as is the case for the vast majority of equivalent surface temp measurements.
BioBob, either thermometers are accurate enough to be clinically useful or they're not. You need to either upgrade your opinion of the accuracy of thermometers or deny that they are clinically useful. Which is it?
Ronald, stop behaving like a moron and allow yourself to learn something. NO, NOT ALL THERMOMETERS ARE NOT ACCURATE ENOUGH TO BE CLINICALLY USEFUL (FOR MEASURING HUMAN BODY TEMP) - PERIOD. Some are better for that use and more accurate for that use than others because they are designed and calibrated for that use but they still have an innate level of error. A rectal thermometer measurement from the rectum is innately more accurate than a ear or mouth based temperature, for instance. But that type of thermometer is not accurate or suitable for measuring temperatures in Antarctica, is it, since it doesn't even report temperatures likely to be encountered there ? You should only stick that thermometer up your a$$, and as many times as it would take to make you understand the nature of repeatability of observations.
Ronald, you either must upgrade your knowledge of what a particular thermometer is accurate and useful for and the nature and behavior of that type of temperature reading or deny that you have a properly functioning brain (and rectum) at all. Which is it ?
You need a serious lesson in precision of concept and expression, dood. Stop using the general to describe the specific. Also you should try sticking a Galileo thermometer up your rectum and see how that works out for a useful clinical measurement.
So BioBob, are you saying that thermometers can be accurate enough to be useful clinically, despite being prone to all the sources of error you mentioned earlier?
Ronal: "there was no Minoan Warm Period, Roman Warm Period, or Medieval Warm Period with global temperatures higher than today."
Yes, there was. I've posted the graphs from the greenland ice core.
The data ends 95 years ago with temperatures 1.2C cooler than the MWP and only .8C claimed warming took place int he 20th century.
Roman was 1C warmer than MWP. Minoan was 2C higher than MWP.
The data is here: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/isotopes/gisp2_temp_accum_alley2000.txt
Ronald, CO2 went up after the last 3 interglacials started because of plant growth = more CO2
"Air trapped in bubbles in polar ice cores constitutes an archive for the reconstruction of the global carbon cycle and the relation between greenhouse gases and climate in the past. High-resolution records from Antarctic ice cores show that carbon dioxide concentrations increased by 80 to 100 parts per million by volume 600 ± 400 years after the warming of the last three deglaciations. Despite strongly decreasing temperatures, high carbon dioxide concentrations can be sustained for thousands of years during glaciations; the size of this phase lag is probably connected to the duration of the preceding warm period, which controls the change in land ice coverage and the buildup of the terrestrial biosphere."
Anthony Watt's surface stations project has documented many problems with thermometers.
He says the most common is that MMTS requires cables to be 1/4 mile away from buildings, A/C units etc.
But no one shows up with a trench digger so the thermometers end up be so close so A/C units and buildings the data is worthless.
Both Ronald and I have made the point that CO2 does not have to lead the initial warming coming out of an ice age and get CO2 can help the planet emerge from an ice age. Something else (e.g. long term trends in Earth's orbital inclination) can start the ball rolling. Then a small warming can cause a small CO2 release that causes an additional warming that causes an additional CO2 release.
Given CO2's absorption spectra this seems a very plausible thing to believe. CO2 really does absorb some infrared. So we expect it to cause a warming effect.
Is is really the case that more plant growth causes more CO2 release? Or that warming causes release of CO2 from the oceans? Is it well established the relative contributions of different factors that influence CO2 concentrations during a complete cycle from glacial to interglacial to glacial again?
Bruce, you've provided an ice core temperature reconstruction for one location, but to get an idea of global temperatures it's necessary to look at multiple ice cores. Once that's done the three periods you mention do not appear to be warmer than current temperatures.
You have mentioned that you think the increase in CO2 over the past few hundred years could be natural. But we have good figures for how much CO2 has been released by burning fossil fuels and good estimates for CO2 released from land clearing, and the amount has been more than sufficient to account for the increase. The increase in CO2 concentration is very well correlated with the burning of fossil fuels. In addition, the quantity of C14 in the atmosphere is what would be expected if the increase had mostly resulted from the burning of fossil fuels. In order for the extra CO2 to be of non-anthropomorphic origin, there would need to be an explanation of where the anthropomorphic CO2 disappeared to. And it would need to be a quite astounding explanation in order to account for current C14 ratios and for the mechanism being able to tell the difference anthropomorphic and non-anthropomorphic CO2 and only removing the former.