About 10 years ago, 550 parts per million of carbon in the atmosphere seemed right - and achievable. Since then, however, the warming effects we're already seeing combined with improved climate modeling brought that number down to 450 parts per million. Difficult to achieve, certainly, but possible - if we turned all our global efforts toward it and made a serious commitment over the next 40 years to move to a low-carbon economy. Now the science suggests that not only is 450ppm not enough to stop catastrophic warming and sea level rise, but once we get there, we may not be able to stop a slow increase to 550ppm and beyond. Beyond, as I've described before, is very very bad place. Believe me when I tell you that you don't ever want to go to there.
It was James Hansen himself who recently published the paper declaring that keeping the planet the way we like it means keeping atmospheric carbon levels at no more than 350ppm. Unfortunately, the difference between 450ppm and 350ppm is a yawning chasm both in scientific and political terms. It's one thing to figure out how to slow down a hurtling freight train and bring it to a halt. It's another thing to have to throw it into reverse.
And so, when Al Gore spoke in Poland last week and declared "Even a goal of 450 parts per million, which seems so difficult today, is inadequate... We... need to toughen that goal to 350 parts per million" and he didn't get laughed out of the room, it meant that maybe we could move the goalposts and the big kids (i.e. China, Russia, the US and Europe) wouldn't take their balls and go home. Because without unanimity on this front, you're likely to see lots of responses like Australia's, who recently proposed wimpy emissions cuts since wimpy "targets are broadly consistent with other developed countries" and their wimpy climate laws. Wimpy's added.
As Bill McKibben, founder of 350.org, a group dedicated to moving those goalposts as soon as possible, put it:
These interminable [climate treaty] talks are designed to build a machine that would halt the atmospheric concentration of carbon dioxide somewhere in the neighborhood of 450 to 550 parts per million. They're so loaded with loopholes, and the timetables are so slow, that they probably wouldn't accomplish even that, but that's the goal. The theory is that the world we need is a 450 world, based on the science from five and 10 and 15 years ago.That there is movement to have a climate treaty reflect current science may, in the end, be the difference between saving the planet and, well, not.
So as Obama introduces his environmental team today, it's worth keeping an ear out for that new magic number of 350. You may not hear it today, but it will undoubtedly come up at Steven Chu's, Lisa Jackson's or Carol Browner's confirmation hearings. Whether or not the Obama administration formally endorses this lower target for all of our climate change efforts is quickly becoming the only question that matters. I sure hope someone asks it.