ARCTIC HOTTER THAN ANY TIME SINCE JESUS

Arctic Temperatures Are Warmest in 2,000 Years
Andrea Thompson, 3 September 2009 (Live Science)

"Arctic air temperatures in the 1990s were the warmest in the last 2,000 years and were a result of rising greenhouse gas levels, a new study concludes.

"The findings, detailed in the Sept. 4 issue of the journal Science, also suggest that if it weren’t for these manmade pollutants, temperatures around the North Pole would actually be cooling as a result of natural climate patterns…The researchers uncovered this masked cooling trend by reconstructing Arctic temperatures over the past two millennia with data from Arctic lake sediments, glacial ice and tree rings…"

The trend is easy to see. (click to enlarge)

"These natural archives indicated a pervasive cooling across the Arctic on a decade-by-decade basis that is related to an approximately 21,000-year cyclical wobble in Earth's tilt relative to the sun…[that] has gradually reduced the intensity of sunlight reaching the Arctic in the Northern Hemisphere's summertime…[S]ummer temperatures in the Arctic, in step with the reduced energy from the sun, cooled at an average rate of about .35 degrees Fahrenheit (0.2 degrees Celsius) per thousand years. The temperatures eventually bottomed out during the "Little Ice Age," a period of widespread cooling that lasted roughly from the 16th to the mid-19th centuries…[The study] isolates the temperature changes of the Arctic region from the larger signal of the Northern Hemisphere…

"Even though the orbital cycle that produced the cooling continued, it was overwhelmed in the 20th century by human-induced warming caused by the buildup of greenhouse gases, such as carbon dioxide, in the atmosphere…The study found that the 10 years from 1999 to 2008 was the warmest in the Arctic in two millennia. Arctic temperatures are now 2.2 degrees Fahrenheit (1.2 C) warmer than in 1900…"

These remarkable images make more vivid the way the earth’s frozen parts are changing with the climate. From NASAexplorer via YouTube

"The scientists compared the temperatures inferred from the field-based data with computer model simulations. The model's estimate…was consistent with the analysis of the lake sediments and other natural archives. These results give scientists more confidence in computer projections of future Arctic temperatures…

"The new study follows previous work showing that temperatures over the last century warmed almost three times faster in the Arctic than elsewhere in the Northern Hemisphere. This phenomenon, called Arctic amplification, occurs as highly reflective Arctic ice and snow melt away, allowing dark land and exposed ocean to absorb more sunlight. This amplification could lead to potentially catastrophic melting of Arctic sea ice and land-based glaciers…"