Global climate change is a serious environmental problem that poses significant risks to human society. Our way of life, including where we live, how we work, and how we enjoy leisure activities, is closely tied to the climate. The impacts of past climate variations, like El Niño and droughts, have already caused economic harm and suffering. However, the projected climate changes for the 21st century are expected to be much larger and more severe. This means that the potential human impacts of these changes are likely to be even greater than what we have experienced in the past century.