Today, I went to the SF International Day of Climate Action. This was one of 1000's of events around the world organized by 350.org and Greenpeace to bring the world's attention to the fact that we must reduce the concentration of CO2 in the atmosphere down to 350 ppm to avoid the worst effects of climate change. We are currently at 389 ppm and rising. Check out 350.org to see the picture of all of us on the ground spelling out 350! I was somewhere in the 5.