While some argue that there's no "proof" that humans are warming the planet, certainly scientists across the world disagree. In his course "Energy and Climate: Science for Citizens of Global Warming," Professor Richard Wolfson provides the following arguments supporting serious global warming: 1. CO2 (carbon dioxide) has increased by over 30% since 1750. 2. CO2 is the dominant contributor to the greenhouse effect though other gases (methane, nitrous oxide, and CFCs) also contribute. 3. The US is responsible for about 20% of global CO2 emissions with a per capita emission of 20 tons per year. 4. By 2100, the atmospheric CO2 concentration is expected to double the pre-industrial level. Course lecture title