Earth to get hotter despite global warming slowdown
The earth's climate would continue to warm during this century, on track with previous estimates despite the recent slowdown in the rate of global warming, a NASA study shows.
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.
Global temperatures have increased at a rate of 0.22 Fahrenheit (0.12 Celsius) per decade since 1951.
But since 1998, the rate of warming has been only 0.09 F (0.05 C) per decade - even as atmospheric carbon dioxide continues to rise at a rate similar to previous decades.
Carbon dioxide is the most significant greenhouse gas generated by humans.
"The research determines how much global temperatures would change as atmospheric carbon dioxide continues to increase - at about 1 percent per year - until the total amount of atmospheric carbon dioxide has doubled," explained Drew Shindell, a climatologist at NASA's Goddard Institute for Space Studies in New York.
The research 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.
Depending on their make-up, some aerosols cause warming, while others create a cooling effect.
In order to understand the role played by carbon dioxide emissions in global warming, it is necessary to account for the effects of atmospheric aerosols.
The new 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 were not so but forewarned is forearmed," Shindell noted in a paper published in the journal Nature Climate Change.
Some recent research, aimed at fine-tuning long-term warming projections by taking this slowdown into account, suggested earth may be less sensitive to greenhouse gas increases than previously thought.
The Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), which was issued in 2013 and was the consensus report on the state of climate change science, also reduced the lower range of earth's potential for global warming.
(Posted on 13-03-2014)