Global Warming

Global warming is the long-term increase in the average temperature of the Earth's surface and oceans observed over recent generations. It is the most prominent aspect of broader climate change. The principal cause is the strengthening of the greenhouse effect: gases in the atmosphere trap heat that the Earth would otherwise radiate to space, and human activities have raised the concentration of these gases substantially, so the planet retains more heat than before.

The main source of the additional greenhouse gases is the burning of fossil fuels, which releases carbon dioxide, along with other gases from agriculture, industry, and changes in land use. As emissions accumulate in the atmosphere, the climate system gradually adjusts to the extra trapped energy. Because the oceans and atmosphere store and move heat over long periods, the warming unfolds over decades rather than instantly, and its effects extend well beyond temperature alone.

The impacts of global warming include rising sea levels, the retreat of glaciers and ice, shifts in weather patterns, and stress on ecosystems and the species within them. Concern over these effects has prompted international cooperation, including the Kyoto Protocol, an agreement under which participating countries committed to limiting their greenhouse gas emissions. Scientists monitor the climate system and compile emissions inventories to understand the changes, while efforts to limit warming focus on reducing the burning of fossil fuels and curbing other sources of pollution.

Frequently asked questions

What causes global warming?

It is caused mainly by rising levels of greenhouse gases, especially carbon dioxide from burning fossil fuels, which trap more of the Earth's heat in the atmosphere.

What was the Kyoto Protocol?

The Kyoto Protocol was an international agreement under which participating countries committed to limiting their emissions of greenhouse gases.

What are some impacts of global warming?

Impacts include rising sea levels, melting ice and glaciers, changing weather patterns, and added stress on ecosystems and the species that live in them.