Monday, November 4, 2013

Hottest September On Record, Fastest Pacific Warming In 10,000 Years, Warmest Arctic In 120,000 Years

By Joe Romm on November 3, 2013 at 11:47 am

Temperature change over past 11,300 yearsTemperature change over past 11,300 years (in blue, via Science, 2013) plus projected warming on humanity’s current emissions path (in red, via recent literature.
It’s been a hot week for global warming.
NASA released global temperature data showing that this September tied with 2005 for the warmest September on record. That’s doubly impressive since 2005 was warmed by an El NiƱo and accompanying warm Pacific ocean temperatures, whereas 2013 has had cooler Pacific temperatures all year.
Greenhouse gases keep warming the planet to unprecedented levels with unprecedented speed. That’s the conclusion of two new studies out this week.
The first, “Unprecedented recent summer warmth in Arctic Canada,” concludes: “Our results indicate that anthropogenic increases in greenhouse gases have led to unprecedented regional warmth.”
How unprecedented? The news release explains:
Average summer temperatures in the Eastern Canadian Arctic during the last 100 years are higher now than during any century in the past 44,000 years and perhaps as long ago as 120,000 years, says a new INSTAAR study.
The study is the first direct evidence the present warmth in the Eastern Canadian Arctic exceeds the peak warmth there in the Early Holocene, when the amount of the sun’s energy reaching the Northern Hemisphere in summer was roughly 9 percent greater than today, said study leader Gifford Miller.
The Holocene is our current geological epoch. It began after Earth’s last Ice age ended some 11,700 years ago. The release notes that, “The ice cores showed that the youngest time interval from which summer temperatures in the Arctic were plausibly as warm as today is about 120,000 years ago.”
What does the unprecedented warming mean?
“The key piece here is just how unprecedented the warming of Arctic Canada is,” said Miller, also an INSTAAR fellow. “This study really says the warming we are seeing is outside any kind of known natural variability, and it has to be due to increased greenhouse gases in the atmosphere.”
And it isn’t just the level of warming that is unprecedented. It is also the rate of warming.
Columbia University’s Earth Island Institute explained that in an article Thursday, “Is Global Heating Hiding Out in the Oceans?“:
… a new study in the leading journal Science adds support to the idea that the oceans are taking up some of the excess heat, at least for the moment. In a reconstruction of Pacific Ocean temperatures in the last 10,000 years, researchers have found that its middle depths have warmed 15 times faster in the last 60 years than they did during apparent natural warming cycles in the previous 10,000.
“We’re experimenting by putting all this heat in the ocean without quite knowing how it’s going to come back out and affect climate,” said study coauthor Braddock Linsley, a climate scientist at Columbia University’s Lamont-Doherty Earth Observatory. “It’s not so much the magnitude of the change, but the rate of change.”
We are experimenting on our previously stable climate without wisdom or morality, we are experimenting on our children and grandchildren without their consent. If we don’t stop ASAP, it won’t end well.

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