Prior to the industrial era, the atmosphere was at about 280 parts per million of carbon dioxide. Now, we are about 387 and growing at nearly 2 ppm per year.
The ‘old’ (a few years ago) scientific consideration was that it seemed we could stabilize, without utterly catastrophic risk, at 450 ppm or below. This is the guiding thinking behind cutting carbon emissions 80 percent by 2050.
Jim Hansen, NASA and one of the strongest voices in climate research, came out with work stating that we must fall to 350 ppm to avoid catastrophic climate change, considering the impacts that we are already seeing globally. 350 is required, Hansen tells us,
If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted.
We face a simple challenge, as a society (and species): 350 or bust!
350.org (from the same people who Stepped it Up) is organizing ralies around the globe, from the Great Wall to the Eiffel Tower, from your backyard to mine, to call attention to the critical challenge and the opportunities created through addressing climate change.
As Bill McKibben wrote last month,
All of a sudden it isn’t morning in America, it’s dusk on planet Earth.
“Dusk on planet Earth …” Bill has a way with words, words to communicate the seriousness of the threat we face and the challenges we can surmount.
There’s a number — a new number — that makes this point most powerfully. It may now be the most important number on Earth: 350. As in parts per million of carbon dioxide in the atmosphere.
Forget inflation rate. Forget price of gasoline. Forget grade point average. 350 is about survival of the globe’s biodiversity and, potentially, survivability of a modern human society.
our last chance; you just can’t do this one lightbulb at a time.
Change those lightbulbs but forget about patting yourself on the back for having done so.
Civilization is what grows up in the margins of leisure and security provided by a workable relationship with the natural world. That margin won’t exist, at least not for long, as long as we remain on the wrong side of 350. That’s the limit we face.
“Margin of leisure and security … ” A planet under stress from catastrophic climate change will have no meaningful margin.