Earth's climate likely to continue warming despite slowdown
Researchers have shown that Earth's climate likely will continue to warm during this century on track with previous estimates, despite the recent slowdown in the rate of global warming.
This research hinges on a new and more detailed calculation of the sensitivity of Earth's climate to the factors that cause it to change, such as greenhouse gas emissions.
Drew Shindell, a climatologist at NASA's Goddard Institute for Space Studies in New York, found Earth is likely to experience roughly 20 percent more warming than estimates that were largely based on surface temperature observations during the past 150 years.
To put a number to climate change, researchers calculate what is called Earth's "transient climate response." This calculation determines how much global temperatures will change as atmospheric carbon dioxide continues to increase - at about 1 percent per year -- until the total amount of atmospheric carbon dioxide has doubled.
The estimates for transient climate response range from near 2.52 F (1.4 C) offered by recent research, to the IPCC's estimate of 1.8 F (1.0 C). Shindell's study estimates a transient climate response of 3.06 F (1.7 C), and determined it is unlikely values will be below 2.34 F (1.3 C).
Shindell's paper further focuses on improving our understanding of how airborne particles, called aerosols, drive climate change in the Northern Hemisphere. Aerosols are produced by both natural sources - such as volcanoes, wildfire and sea spray - and sources such as manufacturing activities, automobiles and energy production.
Shindell's climate sensitivity calculation suggests countries around the world need to reduce greenhouse gas emissions at the higher end of proposed emissions reduction ranges to avoid the most damaging consequences of climate change. "I wish it weren't so," said Shindell, "but forewarned is forearmed."
The paper has been published in the journal Nature Climate Change.
(Posted on 12-03-2014)