Green Options

According to the NAU researchers, the warming that occurred in the 20th Century and early 21st Century, “contrasts sharply” with the millennial-scale cooling trend; the last half-century being the warmest in the record, and, the decade from 1999 - 2008 being the warmest decade of the last 200 decades. Over all average temperatures were 1.4° C (about 2.5° F) warmer than the projected value based on the linear cooling trend.

According to the journal Nature Geosciences, “increasing concentrations of black carbon have substantially contributed to rapid Arctic warming during the past three decades.”

A paper from that journal, “Climate response to regional radiative forcing during the twentieth century,” was authored by climate researchers Drew Shindell, at the NASA Goddard Institute for Space Studies, and Greg Faluvegi of Columbia University. Shindell, Faluvegi, and many other climate scientists believe that limiting black carbon sources may “buy the world some time” in the race to control climate change as richer nations develop their climate change policies and begin taking the slow steps towards overhauling their carbon heavy energy sources.

The researchers assert that aerosols are responsible for “half or more” of Arctic warming. Unexpectedly, their paper’s claims and recommendations sparked a flurry of critical emails, perhaps due to confusion over the atmospheric roles of different aerosols.

A new study from the journal Nature Geoscience has found that 50% of the total temperature increases in the Arctic over the last century have been due to black carbon, a substance that only stays in the atmosphere for several days to weeks.

This means that if black carbon emissions were immediately halted, it may only take a few weeks for warming trends to reverse by half.

Temperatures in the Arctic last fall hit record highs, an international team of scientists reported Thursday. According to the authors of the annual Arctic Report Card, temperatures were more than 9 degrees Fahrenheit above normal and are predicted to remain nearly as high this year.

“The year 2007 was the warmest year on record in the Arctic,” said Jackie Richter-Menge, a climate expert at the Cold Regions Research and Engineering Laboratory in Hanover, N.H, and editor of the latest Arctic Report Card.

The material presented in the paper is peer-reviewed by topical experts of the Climate Experts Group of the Arctic Council.