Reposted from mole333 by brooklynliberal
About 6 years ago, one of the top climate scientists, Jim Hanson (who my wife indirectly worked for at the time), declared we have only 10 years left to mitigate the effects of global warming before we just have to take the full consequences of our stupidity right in the face. He got some criticism from this statement even among climate scientists because of the apparent precision of his estimate, but the gist of his warning is valid: we have a VERY limited time to act to mitigate the effects of global warming, and it is NOW, like RIGHT NOW, that we have to deal with this crisis.
Since he made his warning, the actual pace of global warming effects has actually ACCELERATED. So we might even have LESS time than Jim Hanson suggested. Was his warning excessively precise? Yeah, sure it was. We can't know precisely how much time we have left, but I don't think he was that far off and the more scientific info that comes in, the more I am convinced that our time to act is running out.
Arctic ice volume is expected, at current rate of decline, to reach zero (that means an ice free Arctic Ocean!) around 2015 (maybe 2016 if we are lucky!) according to modeling from the PIOMAS ice volume project at the University of Washington in Seattle. As that happens we WILL reach a critical tipping point in approximately the same time frame.
Now I personally don't think that all the supposed tipping points that hit the internet are valid. But there is one VERY clear, VERY frightening tipping point that WILL occur approximately in the same time frame as an ice-free Arctic Ocean, which means around 2015 or so. That is the release of methane that is frozen in the Arctic. From BBC News:
"In 2007, the water [off northern Siberia] warmed up to about 5C (41F) in summer, and this extends down to the sea bed, melting the offshore permafrost."
Among the issues this raises is whether the ice-free conditions will quicken release of methane currently trapped in the sea bed, especially in the shallow waters along the northern coast of Siberia, Canada and Alaska.
Methane is a much more potent greenhouse gas than carbon dioxide, though it does not last as long in the atmosphere...
"With 'business-as-usual' greenhouse gas emissions, we might have warming of 9-10C in the Arctic.
"That will cement in place the ice-free nature of the Arctic Ocean - it will release methane from offshore, and a lot of the methane on land as well."
This would - in turn - exacerbate warming, across the Arctic and the rest of the world.
The release of this much methane into the atmosphere is one of the MOST frightening things in our near future. MUCH more so than a nuclear Iran or the deficit or pretty much anything else we are facing. If we don't act RIGHT NOW
to stop it, this critical tipping point WILL happen within the next 5-10 years. We will see a MASSIVE change in our climate if we don't work hard NOW to stop it. And the result will be devastating to each and every one of us.
Got that? We are RIGHT NOW at the tipping point and just about EVERY action YOU PERSONALLY take influences that tipping point.
If you have kids (like I do) look them in the eyes and ask yourself it you have done enough to stop this tipping point that will slam your kids or your grand kids like a sledgehammer.