An introduction to climate on Earth. How Earth's climate has changed in the past and its evolving response to the rapid increase in carbon dioxide and methane happening today. Model projections of future climate and associated risks. Development of climate policies in face of uncertainty in these projections and risks. Enrollment is limited. Satisfies the menu requirement of the Caltech core curriculum. Juniors and Seniors who have satisfied their menu course requirement should enroll in ESE 101.