2011 December 11 Sunday
Warming World Brings More Shrubbery

You know which terrors of the forest are going to support global warming.

Scientists have used satellite data from NASA-built Landsat missions to confirm that more than 20 years of warming temperatures in northern Quebec, Canada, have resulted in an increase in the amount and extent of shrubs and grasses.

This is great news for The Knights Who Say "Ni!"

But I fear more shrubbery will just lead to more demands for shrubbery.

Update: What if the knights who say "Ni!" expand in number in a hotter future world? What if shrubbery just encourages them to expand their ranks? What then? Why isn't this debated? Why don't we hear about this danger? Why the cover-up?

By Randall Parker    2011 December 11 09:46 PM   Entry Permalink | Comments (3)
2010 February 16 Tuesday
100 Million Year Ago Volcanoes Cut Oxygen Supply

The natural history of the planet Earth is full of extreme events that would wipe out humans if they occurred today.

Geoengineering -- deliberate manipulation of the Earth's climate to slow or reverse global warming -- has gained a foothold in the climate change discussion. But before effective action can be taken, the Earth's natural biogeochemical cycles must be better understood.

Two Northwestern University studies, both published online recently by Nature Geoscience, contribute new -- and related -- clues as to what drove large-scale changes to the carbon cycle nearly 100 million years ago. Both research teams conclude that a massive amount of volcanic activity introduced carbon dioxide and sulfur into the atmosphere, which in turn had a significant impact on the carbon cycle, oxygen levels in the oceans and marine plants and animals.

For a planet that is 4.5 billion years old 100 million years ago is recent geological history. What I want to know: Can Earth do this level of volcanic eruption again?

The volcanic eruptions cut ocean oxygen so much that one-third of marine life died.

Both teams studied organic carbon-rich sediments from the Western Interior Seaway, an ancient seabed stretching from the Gulf of Mexico to the Arctic Ocean, to learn more about a devastating event 94.5 million years ago when oxygen levels in the oceans dropped so low that one-third of marine life died.

The authors of the first paper, titled "Volcanic triggering of a biogeochemical cascade during Oceanic Anoxic Event 2," reveal that before oxygen levels dropped so precipitously there was a massive increase in oceanic sulfate levels. Their conclusion is based on analyses of the stable isotopes of sulfur in sedimentary minerals from the central basin of the Western Interior Seaway, located in Colorado.

A sulfate spike in the oceans increased phosphorus availability (how?) and phytoplankton went wild and created massive dead zones.

The researchers theorize that a massive amount of volcanic activity caused this sulfate spike, which triggered a cascade of biogeochemical events. More sulfate led to an abundance of the nutrient phosphorous, which allowed phytoplankton populations in the oceans to multiply. The phytoplankton thrived and then died. Their decomposing bodies depleted oxygen levels in the oceans, leading to the widespread death of marine animals.

We see a similar phenomenon on a smaller (albeit still large) scale today at the mouths of major rivers. Fertilizer run-off from farms causes massive dead zones. We need to restore wetlands that can serve as cleaners of rivers and also reduce agricultural run-off.

By Randall Parker    2010 February 16 10:30 PM   Entry Permalink | Comments (18)
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