The biggest threat, when it comes to climate change and pollution, isn't going to come from us because we only have 300 million people. It's going to come from China with over 1 billion people and India with over 1 billion people.
There's one issue that will define the contours of this century more dramatically than any other, and that is the urgent and growing threat of a changing climate.
Those who deny human-caused climate change offer no compelling evidence to better explain the undeniable rise in atmospheric concentrations of greenhouse gases and global temperature.