Bill McKibben, known to many of you as an environmental writer [ The End of Nature and Deep Economy: The Wealth of Communities and the Durable Future] and activist has a new initiative: 350.org

That would be 350 parts per million [ppm] of CO2, the upper safe limit of the greenhouse molecule in the atmosphere — which we have already passed, at 383, and are heading much higher. James Hansen, one of the earliest high profile scientists to raise loud warnings about CO2 and global warming has said we must drive the the numbers down.

350.Org aims to get the number and understanding of it all over the world. You can help.

Tom Englehardt, in his TomDispatch, introduces the latest McKibben piece.

Already climate change — in the form of a changing pattern of global rainfall — seems to be affecting the planet in significant ways. Take the massive, almost decade-long drought in Australia’s wheat-growing heartland, which has been a significant factor in sending flour prices, and so bread prices, soaring globally, leading to desperation and food riots across the planet.

A report from the Bureau of Meteorology in Australia makes clear that, despite recent heavy rains in the eastern Australian breadbasket, years of above normal rainfall would be needed “to remove the very long-term [water] deficits” in the region. The report then adds this ominous note: “The combination of record heat and widespread drought during the past five to 10 years over large parts of southern and eastern Australia is without historical precedent and is, at least partly, a result of climate change.”

McKibben says:

All of a sudden it isn’t morning in America, it’s dusk on planet Earth.

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 (ppm) of carbon dioxide in the atmosphere.