About global warming

DEFINITION OF GLOBAL WARMING

Global warming is understood to result from an overall, long-term increase in the retention of the sun’s heat around Earth due to blanketing by “greenhouse gases,” especially CO2 and methane. Emissions of CO2 have been rising at a speed unprecedented in human history, due to accelerating fossil fuel burning that began in the Industrial Revolution.

The effects of the resulting “climate change” are uneven and can even produce localized cooling (if warm currents change direction). The climate change may also initiate positive feedback in which the initial impact is further enhanced by its own effects, for example if melting ice reduces the reflective properties of white surfaces (the “albedo” effect) or if melting tundra releases frozen methane, leading to further warming. Debate continues about which manifestations are due to long-term climate change and which to normal climate variability.