The atmosphere is made up of gases held close to Earth by gravity. It consists of different layers including the troposphere closest to Earth, which contains most water vapor and clouds. Weather describes short-term atmospheric conditions while climate refers to average conditions over time in a region. Oceans influence climate by absorbing solar energy and driving global ocean currents. Greenhouse gases like carbon dioxide trap heat in the atmosphere, causing global warming, while planetary albedo from cloud reflection causes global cooling. Human activities have increased greenhouse gases in the troposphere. Rising temperatures will affect rainfall patterns and sea levels in coming decades. Depletion of the ozone layer allows more UV radiation to reach the Earth's surface, damaging living organisms.