The study sought to reconcile different estimates for the Earth's climate sensitivity, or how temperatures change in response to changes in the atmosphere.
Some studies estimate low climate sensitivity, based on the assumption that global average temperatures would respond uniformly to increases of carbon dioxide and other greenhouse gas emissions. But the NASA study showed global temperatures are more sensitive to changes in aerosols and ozone in the atmosphere.
This higher sensitivity could mean a larger and faster temperature response, according to the study.
The study's findings could have “a really profound impact” on the amount of greenhouse gas emissions reductions needed for countries to meet an international goal of limiting temperature increases to 2 degrees Celsius (3.6 degrees Fahrenheit), the study's author, Drew Shindell, a climatologist at NASA's Goddard Institute for Space Studies in New York, told Bloomberg BNA.
“I wish it weren't so,” Shindell said in a statement March 11, “but forewarned is forearmed.”
Global temperatures have increased at a rate of 0.12 degree C (0.22 degree F) per decade since 1951, NASA said. But since 1998, the rate of warming has slowed to only 0.05 C (0.09 F) per decade—even as atmospheric carbon dioxide continues to rise.
IPCC Differs on Global Warming
Some recent research, including the latest report from the Intergovernmental Panel on Climate Change (IPCC), has suggested that the global warming slowdown means Earth may be less sensitive to greenhouse gas increases than previously thought. The IPCC estimated in September that global temperatures will rise by about 1.0 C (1.8 F) as the amount of carbon dioxide in the atmosphere gradually doubles.
But Shindell's research indicates the IPCC may be underestimating temperature changes. As carbon dioxide doubles, temperatures are most likely to rise 1.7 C (3.06 F) and are unlikely to be below 1.3 C (2.34 F), according to his study.
Shindell, who was a lead author for the IPCC's…