This document discusses climate change and its effects. It defines weather as short term conditions in a limited area, while climate describes average conditions over long periods of time in a wide area. Climate is influenced by various biotic and abiotic factors. Greenhouse gases like carbon dioxide, methane and nitrous oxide occur naturally but human activities like burning fossil fuels have increased their levels, causing global warming. Evidence of climate change includes melting glaciers and ice cores, tree ring data, and changes in plant and animal ranges and behaviors. Individual actions like conserving energy and reducing waste can help address climate change.