Canadian study sees global warming for centuries
By Jeffrey Jones
CALGARY, Alberta (Reuters) - Carbon dioxide already emitted into the atmosphere will keep contributing to global warming for centuries, eventually causing a huge Antarctic ice sheet to collapse and lift sea levels, Canadian scientists said on Sunday.
Even the complete abandonment of fossil fuels and halt to emissions cannot prevent devastating ocean warming in Antarctica as well as increasing desertification in North Africa, the research finds.
Even so, many of the negative consequences in the Northern Hemisphere, such as loss of Arctic sea ice, are reversible. That means global efforts to cut greenhouse gases are not a waste of effort and money, said Shawn Marshall, a University of Calgary geography professor and one of the study's authors.
"But there are some parts of the climate that have a lot of inertia and it will take many centuries before they start to reverse," said Marshall.
The study, led by Nathan Gillett of the Canadian Center for Climate Modeling and Analysis, is published in the journal Nature Geoscience.
Using simulations with a climate model, the scientists estimated the effects on climate patterns for the next 1,000 years by stopping emissions completely in 2010 and in 2100.
Major differences of the impacts in various regions lie in the centuries it takes for heat to circulate from the North Atlantic through the world's ocean currents and into the deep sea, Marshall said.
"The atmosphere cools pretty quickly when atmospheric gases go down and surface water will cool, but that doesn't reach the deeper waters of the ocean for a long time," he said. Continued...