U.N. warns agriculture must change to slow global warming

Humans must drastically alter food production to prevent the most catastrophic effects of global warming, according to a new report from the United Nations panel on climate change.

The panel of scientists looked at the climate change effects of agriculture, deforestation and other land use, such as harvesting peat and managing grasslands and wetlands. Together, those activities generate about a third of human greenhouse gas emissions, including more than 40% of methane.

That’s important because methane is particularly good at trapping heat in the atmosphere. And the problem is getting more severe.

“Emissions from agricultural production are projected to increase,” the authors warn. “Delaying action” on reducing greenhouse gas emissions, they continue, “could result in some irreversible impacts on some ecosystems.”

This is the latest in a series of reports from the U.N.’s Intergovernmental Panel on Climate Change. The new report adds weight and detail to a warning put out by the same panel of scientists last fall, in which they sounded the alarm about the inadequacy of the pledges countries have made so far to reduce greenhouse gas emissions.

At that time, the panel broadly suggested that farmland would need to shrink and forests would need to grow to keep Earth from getting more than 1.5 degrees Celsius hotter than it was in the preindustrial era. Global temperatures have already risen about 1 degree Celsius in the past 150 years.

To meet that temperature target, global greenhouse gas emissions will need to fall by 40% to 50% in the next decade. Scientists say the only way to achieve that reduction is to significantly increase the amount of land that’s covered in trees and other vegetation and significantly reduce the amount of methane and other greenhouse gases that come from raising livestock such as cows, sheep and goats. More at NPR.org