In December of 2007, NASA's James Hansen presented his conclusions. According to climate activist Bill McKibben, Hansen has given a simple measure of what is happening to the planet.
Are Hansen and McKibben right? Most of us aren't equipped to know. Those of us not on coal company payrolls or angrily dismissive of "smarty pants" opinion have to believe the scientific consensus that human-caused activity is driving global warming.
Are we, collectively, going to do anything about it? It feels insane to even be asking that question.