Our last chance is fast running out
May 11th, 2008 by Jim Just“if humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm.”
This stark warning is from the abstract of a recent report by James Hansen’s team of scientists.
Things aren’t looking good. Two weeks ago came the news that atmospheric carbon dioxide levels are rising faster than ever – and methane, an even more potent greenhouse gas, is soaring as well as the frozen north begins to thaw. If the Arctic ice disappears as feared, the white reflector that sent 80% of incoming solar radiation back into space will have turned to blue water that absorbs 80% of the sun’s heat. We’re already seeing feedbacks taking over. What humans have started, Earth may finish.
If we do everything right, we could see carbon emissions start to fall fairly rapidly and the oceans begin to pull some of that CO2 out of the atmosphere. Before the century was out, we could be on track back to 350. We might stop just short of irreversible tipping points.
“[It] means that political systems around the world would have to take enormous and painful steps right away. It means no more new coal-fired power plants anywhere, and plans to quickly close the ones already in operation. (Coal-fired power plants operating the way they’re supposed to are, in global warming terms, as dangerous as nuclear plants melting down.) It means making car factories turn out efficient hybrids next year, just the way U.S. automakers made them turn out tanks in six months at the start of World War II. It means making trains an absolute priority and planes a taboo.
“It means making every decision wisely because we have so little time and so little money, at least relative to the task at hand. And hardest of all, it means the rich countries of the world sharing resources and technology freely with the poorest ones so that they can develop dignified lives without burning their cheap coal.”
As McKibben says, this the most obvious duty humans have ever faced.