James Hansen - "One Degree And We're Done For" - New Scientist

[hatrack]

Further global warming of 1 °C defines a critical threshold. Beyond that we will likely see changes that make Earth a different planet than the one we know." So says Jim Hansen, director of NASA's Goddard Institute for Space Studies in New York. Hansen and colleagues have analysed global temperature records and found that surface temperatures have been increasing by an average of 0.2 °C every decade for the past 30 years. Warming is greatest in the high latitudes of the northern hemisphere, particularly in the sub-Arctic boreal forests of Siberia and North America. Here the melting of ice and snow is exposing darker surfaces that absorb more sunlight and increase warming, creating a positive feedback.

Earth is already as warm as at any time in the last 10,000 years, and is within 1 °C of being its hottest for a million years, says Hansen's team. Another decade of business-as-usual carbon emissions will probably make it too late to prevent the ecosystems of the north from triggering runaway climate change, the study concludes (Proceedings of the National Academy of Sciences, vol 103, p 14288).

The analysis reinforces a series of recent findings on accelerating environmental disruption in Siberia, northern Canada and Alaska, underlining a growing scientific consensus that these regions are pivotal to climate change. Earlier this month, NASA scientists reported that climate change was speeding up the melting of Arctic sea ice. Permanent sea ice has contracted by 14 per cent in the past two years (Geophysical Research Letters, vol 33, L17501). However, warming and melting have been just as dramatic on land in the far north.

A meeting on Siberian climate change held in Leicester, UK, last week confirmed that Siberia has become a hotspot of global climate change. Geographer Heiko Balzter, of the University of Leicester, said central Siberia has warmed by almost 2 °C since 1970 - that's three times the global average. Meanwhile, Stuart Chapin of the University of Alaska Fairbanks this week reported that air temperatures in the Alaskan interior have risen by 2 °C since 1950, and permafrost temperatures have risen by 2.5 °C (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0606955103).

EDIT

http://www.newscientist.com/article/mg19125713.300-one-degree-and-were-done-for.html

[phantom power]

1. It's always "another decade." They need to get real.

The positive feedback loops are already in place. Whatever this new world will be, it's coming. Or, maybe it's the old world coming. Again.

[Dogmudgeon]

2. It's already "too late"

The Great End-Pleistocene Climate Change is here, and it's happening now. Part of it, I'll grant, is a natural cycle. But we humans basically kicked the props out from under the system. instead of having a slow, natural transition, we're going to get it all in the space of a few decades.

The choice we are faced with today is a little different than the politicians are talking about. The choice is now between "gloom and doom" and "challenge and triumph".

However, the odds are running heavily in favor of gloom and doom.

--p!

[Boomer]

3. Another "aye" for the gloom

The "challenge" will last thousands, if not millions, of years and no one alive today will ever see the "triumph" of the next speciation.

There always is a "next", but chances are good that most large mamnmals -- of which we are one -- will not weather the shift to a new climate/ecological paradigm.

[indepat]

4. That heresy won't fly with the decider

[Porcupine]

5. I always wanted to visit another planet.

Who new that all I had to do was stay right where I am. No need to join the Air Force, ace physics at MIT or win the national teachers prize. Just sit back, eat chips and watch star track reruns.

[Dead_Parrot]

6. It's life, Jim...

...But not as we know it.

[One_Life_To_Give]

7. Like Global CO2 Emmissions will drop in the next decade

Like Global CO2 Emmissions will drop in the next decade? Yeah right.

It's not If Climate Change is coming.
The question is how bad will it be?
What can people do to help survive the change?

[Javaman]

8. Trying to hold back the brake-less locomotive going down hill...

Even in during a time when all arrows point to doom, our scientists still have hope. Got to love them for that. Sadly, their hope never mixes in politics and general world ignorance. :(