PRINCETON, N.J. — What we are doing to our planet, to our children and grandchildren, and to the poor, by our heedless production of greenhouse gases, is one of the great moral wrongs of our age. This Saturday is a day to stand up against this injustice.
Saturday is "350 Day." The name comes from the number of parts per million of carbon dioxide in the atmosphere that, according to Jim Hansen — perhaps the world's leading climate scientist — we should not exceed if we are to avoid potentially catastrophic climate change. CO2 is already at 386 ppm, and is rising by two ppm a year.
We are approaching a point of no return, at which feedback loops will kick in and continue to warm the planet, no matter what we do. The melting of arctic ice is one example.