Climate change is defined as a significant change in climate, lasting for an extended period, on local or global level, but in everyday use climate change mostly refers to global warming. Global warming is briefly defined as the increase in the average temperature of the Earth, resulting in an increase in the temperature of oceans and near-surface air temperature. In the past 100 years, the global average surface air temperature has increased by 0.7-0.8 °C. According to the Intergovernmental Panel on Climate Change (IPCC), “most of the observed increase in global average temperatures since the mid twentieth century are very likely due to the observed increase in anthropogenic greenhouse gas concentrations”. Humankind has been using fossil fuels (coal, crude oil) since the industrial revolution, thus emitting greenhouse gases, mostly carbon dioxide in the air. As a result, the average global temperature has risen by over 0.7°C in the past hundred years, and if this process is to continue at the same pace, the average temperature will be 2°C higher by the end of the century. Experts say that the current increase in the CO2 content of the atmosphere is unparalleled in history, and 90% of it is caused by burning fossil fuels. The increase in CO2 concentration and the increase in average temperature lead to diverse, already visible local and global problems. These include the increasing frequency and intensity of extreme weather events, the acidification of natural waters and the loss of biodiversity.
Resources: Wikipedia Globálisfelmelegedés.info Greenpeace.org