Arctic summer temperatures at warmest level for 120,000 years

By Andrew Freedman on 1 November 2013

Average summer temperatures in the Eastern Canadian Arctic during the past 100 years are hotter than they have been in at least 44,000 years, and possibly as long as 120,000 years, according to a new study. The study of mosses emerging from beneath receding glaciers on Baffin Island — the world’s fifth-largest island located west of Greenland — confirms that rapid Arctic warming has already put parts of the region in new climatic territory.

Arctic warming is transforming the Far North by melting sea and land ice, speeding spring snowmelt, and acidifying the Arctic Ocean. Arctic warming may even be redirecting the jet stream in the northern midlatitudes, making some types of extreme weather events more likely in the U.S. and Europe.

Departure from average of Arctic surface temperatures during the first decade of the 21st century, as compared to the 1971-2000 average. The map illustrates that no part of the Arctic experienced cooler-than-average conditions during this period.

Credit: NOAA

On Baffin Island, glaciers have been receding approximately 6.5 to 10 feet per year, and they are likely to be gone entirely within the next few centuries if current trends continue, said lead author Gifford Miller of the University of Colorado at Boulder.

The new research, published in the journal Geophysical Research Letters, is the first to present physical evidence that indicates the warming in the Eastern Canadian Arctic exceeds the peak warmth during the Holocene epoch, which began after the last Ice Age ended about 11,700 years ago.

That’s significant because it means that manmade emissions of greenhouse gases have pushed the climate in this part of the world beyond the previous, naturally driven warm period, when incoming solar energy during the Northern Hemisphere summer was about 9 percent greater than it is today.

Miller said he and his colleagues were “shocked” by their findings. They knew the climate of Baffin Island was warming, and that it was warm during a previous period of the Holocene, but, Miller said, “in our minds it was unlikely that the contemporary warmth had exceeded the previous warm period.

“Our data pretty clearly demonstrates that the observed warming now exceeds any plausible explanation by natural variability,” Miller said in an interview. “There is no other explanation that anybody has put forward outside of greenhouse gas emissions that can possibly meet what we’ve observed.”

The valuable insight into the Arctic climate came from an unlikely source — clumps of long-dead and concealed moss that is now emerging from retreating glaciers, after having been killed and entombed under the ice when it first formed.

Miller and his colleagues used radiocarbon dating techniques to gain insight into two key indicators of climate history. First, the moss indicated when, after earlier ice-free periods, the snowline dropped below the observation site and remained there, killing the plants. In other words, the moss showed when it first got cold.

Gifford Miller collects long-dead tundra plants exposed by melting of an Arctic ice cap on Baffin Island, Canada.

Credit: Gifford Miller

Second, the dated samples informed researchers as to when a given site was last ice-free, which was also the last time when summer temperatures at the same site would have been as high or higher than when the plants were last alive, Miller said.

The scientists gathered their samples over three field seasons between 2005-2010, ultimately dating 145 of the samples. The scientists found that at four small summit ice caps, rooted vegetation exposed by the shrinking ice cover pre-dated the Holocene period, dating back all the way to at least 44,000 years ago, close to the 50,000-year limit of when radiocarbon dating techniques are considered reliable.

Because of the uncertainties in radiocarbon dating techniques, as well as information gleaned from climate records from nearby Greenland, the study found that the last time summer temperatures “were plausibly as warm as present” is about 120,000 years ago.

“We never even in our wild imaginations thought we’d be getting dates that were at the limits of radiocarbon” dating techniques, Miller said. “It challenges our whole paradigm.”

[continued ...]

Ajax wrote on Nov 3^rd, 2013 at 11:44am:

So says the sock puppet for the fossil fuel industry

muso wrote on Nov 3^rd, 2013 at 12:23pm:


Ha as usual you have no defence and just mince words....!!!!

# wrote on Nov 3^rd, 2013 at 12:57pm:
You mean more like a propagandist for the fossil fuel corporate interests, not here to debate the truth or otherwise but to push a political message for his fossil fuel corporate masters. The guy's a worm.

Strangely enough (NOT) the OP's study is being met with derision and utter disbelief - more junk science from the grant funded fraudsters and the AGW doomsday religious twats.

Please update yourselves to the current debunking of junk science and associated doomsday nonsense at...

http://wattsupwiththat.com/2013/11/02/miller-et-al-s-unprecedented-recent-summer...
Conclusions

From the foregoing data and analyses, what is abundantly clear is that the Miller et al. paper is so badly flawed with unwarranted assumptions, poorly thought out assertions, and astonishingly bad logic that their conclusion “temperatures of the past century must have exceeded those of any century in more than 44 ka” cannot be considered valid. How could reputable scientists come to such incorrect conclusions? Perhaps the last sentence in their conclusions section gives us a clue: “anthropogenic emissions of greenhouse gases have now resulted in unprecedented recent summer warmth that is well outside the range of that attributable to natural climate variability.” Even if the conclusions in the paper were correct, they wouldn’t prove anything about CO2 as the cause of climatic warming, so this statement suggests that the real purpose of the paper was to push CO2 at the expense of objective science.


Just off to cash my bonus cheque from the fossil fuel industry, I plan on buying a new SUV with the cash, one that burns lots of petrol and I don't care because I have a Fuel Card provided, so lots of Sunday drives through the city and beaches, out to the national parks to terrorise some dumb animals (green voters that is) 

# wrote on Nov 3^rd, 2013 at 12:57pm:


I am losing count of WHO exactly muso is in this outrageous forum

Incidentally who are you?

Who is Ajax?

Ajax wrote on Nov 3^rd, 2013 at 1:10pm:

No, Ajax. I'm not about to let you lure me down that rabbit-hole. If you truly don't understand (which I doubt), then you've confirmed the appearance to which I alluded.