Study finds Arctic warming three-fold compared to global patterns
by Hannah Bird , Phys.org

Global warming is an omnipresent issue, with widespread initiatives to draw down emissions and mitigate against the International Panel on Climate Change's worse-case scenario predictions of 3.2°C of warming by 2100 (relative to pre-Industrial levels). Current measurements stand at 1.1°C of warming across Earth, but polar regions are experiencing enhanced surface warming compared to the rest of the planet.

Quantifying this amplification of warming in the Arctic (>65°N) compared to global means, and the mechanisms behind this, is the subject of new research published in Nature Geoscience.

Dr. Wenyu Zhou, of the Pacific Northwest National Laboratory, U.S., and colleagues investigated previous reports of Arctic amplification factors of two to four since 1979, and determined a factor of three to be more likely based upon Earth's natural variability modulating temperature change.

"Natural variability is like noise," Dr. Zhou explains. "Even in the absence of external forcing (such as changes in greenhouse gases), the state of the climate system can fluctuate due to its coupled dynamics of ocean, atmosphere and land. Such variability can occur at various timescales (interannual, decadal, multi-decadal) depending on the corresponding 'mode.'

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