More Feedback Loops!

Rubrik: More Feedback Loops! sön okt 07, 2007 2:29 am

Citat :: BERKELEY, CA —Studies have shown that global climate change can set-off positive feedback loops in nature which amplify warming and cooling trends. Now, researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California at Berkeley have been able to quantify the feedback implied by past increases in natural carbon dioxide and methane gas levels. Their results point to global temperatures at the end of this century that may be significantly higher than current climate models are predicting.

Using as a source the Vostok ice core, which provides information about glacial-interglacial cycles over hundreds of thousands of years, the researchers were able to estimate the amounts of carbon dioxide and methane, two of the principal greenhouse gases, that were released into the atmosphere in response to past global warming trends. Combining their estimates with standard climate model assumptions, they calculated how much these rising concentration levels caused global temperatures to climb, further increasing carbon dioxide and methane emissions, and so on.

“Our results reinforce the fact that every bit of greenhouse gas we put into the atmosphere now is committing us to higher global temperatures in the future and we are already near the highest temperatures of the past 700,000 years,” Torn said. “At this point, mitigation of greenhouse gas emissions is absolutely critical.”

Rubrik: Sv: More Feedback Loops! sön okt 07, 2007 12:00 pm

Citat :: "Their four-year study concluded that rising temperatures are increasing wind speeds over the Southern Ocean and preventing it from absorbing more carbon and is causing the sea to release some of the gas that it had stored."