Global warming

The increase in global temperatures is expected to result in other changes, including rises in sea level and changes in the amount and pattern of precipitation. These changes may increase the frequency and intensity of extreme weather events, such as floods, droughts, heat waves, and hurricanes. It may cause higher or lower agricultural yields, glacier retreat, reduced summer streamflows, and contribute to biological extinctions. Although warming is expected to affect the number and magnitude of these events, it is difficult to connect particular events to global warming. Although most studies focus on the period up to 2100, warming (and sea level rise due to thermal expansion) is expected to continue past then, since CO2 has a long average atmospheric lifetime. The term 'global warming' is a specific case of the more general term 'climate change' (which can also refer to cooling, such as occurs during Ice ages). In principle, 'global warming' is neutral as to the causes, but in common usage, 'global warming' generally implies a human influence. However, the UNFCCC uses 'climate change' for human-caused change, and 'climate variability' for other changes. Some organizations use the term 'anthropogenic climate change' for human-induced changes. Global warming is already causing death and disease across the world through flooding, environmental destruction, heat waves and other extreme weather events, according to some scientists. The world's primary international agreement on combating climate change is the Kyoto Protocol. The Kyoto Protocol is an amendment to the United Nations Framework Convention on Climate Change (UNFCCC). Countries that ratify this protocol commit to reduce their emissions of carbon dioxide and five other greenhouse gases, or engage in emissions trading if they maintain or increase emissions of these gases. Although the combination of scientific consensus and economic incentives were enough to persuade the governments of more than 150 countries to ratify the Kyoto Protocol, there is a continuing debate about just how much greenhouse gas emissions warm the planet.