Global Climate Change Introduction: Climate change is a lasting change in weather patterns around average conditions. Some factors like global warming, greenhouse effect, biotic processes are some of the reasons for global climate change. Global average temperatures have changed and so have precipitation patterns. Over the last century, human activities have led to increased emissions of heat-trapping gases, such as carbon dioxide. The earth's average temperature has risen 1.4°F and is expected to rise another 2-13.5°F over the next few decades. Large and potentially large changes in weather and climate could result from small average weather patterns. Many places have experienced changes in the form of floods, heavy rains, frequent heat waves, droughts and improper distribution of rainfall. These climate changes have also left their impact on oceans and glaciers. Glaciers are melting, causing sea levels to rise, oceans are becoming more acidic. These climate changes will pose new challenges to our environment. Greenhouse effect and greenhouse gases: The Earth absorbs a lot of energy from the sun and heats up during the day. It cools by releasing infrared radiation. But greenhouse gases don't let infrared radiation escape into space. This trapping of long-wavelength infrared radiation leads to a higher temperature and more heat at the Earth's surface. In recent decades, human activities tend to release many greenhouse gases into the atmosphere such as carbon dioxide (Co2), methane, carbon monoxide, nitrous oxide, carbon tetrafluoride, hexafluororethane. Most of these greenhouse gases come from the deforestation of the Arctic ice cap and the increased thawing of the Greenland and Antarctic glaciers, from the early flowering of trees and plants in spring. Earth's temperature measurements show surface warming that is consistent with warming of the troposphere and cooling of the stratosphere. This model agrees with global climate changes and also with the thinning of the ozone layer in the stratosphere. There is also the possibility of broader climate changes than current scenarios and predicted satellite data. The occurrence of unexpected changes in the climate increases as human disturbances to the climate system grow. References: http://www.epa.gov/climatechange/basics/http://www.epa.gov/climatechange/science/causes. htmlhttp://downloads.globalchange.gov/usimpacts/pdfs/Global.pdfhttp://www.ucar.edu/learn/1_4_1.htmhttp://hyperphysics.phy-astr.gsu.edu/hbase/thermo/grnhse. html