The earth has warmed by 1.4 degrees since 1880. Climate deniers claim that natural sources, like solar activity, volcanos, and orbital changes have caused the earth to warm. The data published by NASA’s Goddard Institute of Space Studies shows otherwise. Reviewing this clearly and graphically indicates that the increase of greenhouse gases in the atmosphere tracks closely with the observed increase in temperature.

The question now is: how do we reduce human-caused greenhouse gas emissions?

Marco Rubio says that the United States is not a planet, so whatever we do here is not going to fix things. So we might as well do nothing.

I say the United States should show leadership, and other countries will follow. We have always led in the past, and we should lead now.

But then, I am not running for president.