August 18, 2009

Give me a frickin' break - Global Warming and ancient farming methods

Do you want to see a perfect example of politicized "science"? Check out this at CNN:
Study: Global warming sparked by ancient farming methods
Ancient man may have started global warming through massive deforestation and burning that could have permanently altered the Earth's climate, according to a new study by researchers at the University of Virginia and the University of Maryland-Baltimore County.

Primitive slash-and-burn agriculture permanently changed Earth's climate, according to a new study.

The study, published in the scientific journal Quaternary Science Reviews and reported on the University of Virginia's Web site, says over thousands of years, farmers burned down so many forests on such a large scale that huge amounts of carbon dioxide were pumped into the atmosphere. That possibly caused the Earth to warm up and forever changed the climate.

Lead study author William Ruddiman is a professor emeritus of environmental sciences at the University of Virginia and a climate scientist.

"It seems like a common-sense idea that there weren't enough people around 5, 6, 7,000 years ago to have any significant impact on climate. But if you allow for the fact that those people, person by person, had something like 10 times as much of an effect or cleared 10 times as much land as people do today on average, that bumps up the effect of those earlier farmers considerably, and it does make them a factor in contributing to the rise of greenhouse gasses," Ruddiman said.
Now compare this to some real data - taken from this website: Geocraft -- Global Warming
global_temp_CO2_geologic_timeline.jpg
Black line is CO2 and the blue line is temperature. The data is taken from the Vostok Ice Core. They can tell the CO2 as the gas is dissolved in the frozen water. Temperature is determined by proxy from pollen and other debris as well as the ratios of dissolved gasses. The scales are quite different -- but you can plainly see that last quarter inch on the right representing the last 10K years or so. This in no way represents human activity. The CO2 present in the atmosphere is at record lows and on a geological scale, the overall trend is cooling. We had a spate of warming weather in the last 30 years but the high-point was in 1998 and it has been cooling ever since. Yes, there is a link between overall CO2 concentration and Earth temperature but it is the CO2 that lags the temperature by several hundred years, CO2 is not the driver of the temperature... Posted by DaveH at August 18, 2009 8:01 PM | TrackBack