February 16, 2011

Researchers Find Damage Already Done To Climate

New University of Washington research has found that the world is already committed to a warmer climate because of emissions that have occurred up to now.

The researchers said that there would continue to be warming even if the most stringent policies were adopted because there would still be some emissions of heat-trapping greenhouse gases like carbon dioxide and methane.

The team found that even if all emissions were stopped now, temperatures would remain higher than pre-industrial Revolution levels because the greenhouse gasses already emitted are likely to persist in the atmosphere.

Kyle Armour, a UW doctoral student in physics, said it is possible that temperatures would continue to escalate even if all cars, heating and cooling systems, and the sources of greenhouse gases were suddenly eliminated.

He said that is because aerosols would last only a matter of weeks once emissions stopped, while the greenhouse gases would continue on.

"The aerosols would wash out quickly and then we would see an abrupt rise in temperatures over several decades," he said in a press release.

The global temperature is already 1.5 degrees Fahrenheit higher than it was before the Industrial Revolution.

Armour said that in the best-case scenario, the global temperature would actually decline, but it would remain about a half degree higher than pre-Industrial Revolution levels and probably would not drop to those levels again.

The researchers said that there is also a possibility that temperatures would rise up to 3.5 degrees Fahrenheit higher, which is a threshold scientists say could cause significant climate-related change.

Armour said that the overall effect of aerosols is the largest uncertainty in climate research.

He said that climate models used in Intergovernmental Panel on Climate Change assessments take into consideration a much narrower range of the possible aerosol effects than are supported by actual climate observations.

Armour said in a press release that as emissions of greenhouse gases continue, the "climate commitment" to a warmer planet only rises.

"This is not an argument to say we should keep emitting aerosols," he said. "It is an argument that we should be smart in how we stop emitting. And it's a call to action because we know the warming we are committed to from what we have emitted already and the longer we keep emitting the worse it gets."

The study was published in the journal Geophysical Research Letters.


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