Farming keeps the earth cool
New research suggests that farmed fields can counter global warming – and that planting trees to store carbon should be approached with caution.
Fields have a chilling effect on the earth. This "cool farms factor" has mitigated the effects of global warming across the entire continental US, and could continue to do so, new research suggests.
Using a high-resolution climate model, Noah Diffenbaugh of Purdue University in Indiana has calculated how agriculture has influenced the climate in the United States. He found that farming has caused a significant cooling across the US.
The model found that the farmed scenario was 0.19 degrees Celsius cooler than the "wild" scenario. Furthermore, areas covered by mixed fields were 0.36 degrees cooler, and the air above irrigated crops was 1.52 degrees cooler.
Diffenbaugh says that if it weren't for the expansion of agriculture during the 20th century, the US may have felt the effects of global warming more than it has.
The question is how land use will change. Efforts to store carbon by planting trees, for instance, may have mixed consequences because tree cover may increase local warming. This needs to be taken into consideration when deciding how to reward forestation efforts, he says.
New Scientist: Farmers' crops keeping US cool