Astronomy 100
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Astro 100 |
Lecture 5
Global Warming
Outline
- Global Warming
Global Warming
- Global warming refers to the increase in the average temperature of the
Earth's near-surface air and oceans in recent decades and its projected
continuation.
- The global average air temperature near the Earth's surface rose
0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the last 100 years.
- The Intergovernmental Panel on Climate Change (IPCC) concludes that
most of the observed increase in globally averaged temperatures since the
mid-20th century is very likely due to the observed increase
in manmade greenhouse gas concentrations via the greenhouse effect.
- Climate models referenced by the IPCC project that global surface
temperatures are likely to increase by 1.1 to 6.4 °C (2.0 to 11.5 °F)
between 1990 and 2100.
- An increase in global temperatures is expected to cause other changes,
including sea level rise, increased intensity of extreme weather events, and
changes in the amount and pattern of precipitation.
- Other effects of global warming include changes in agricultural yields,
glacier retreat, species extinctions and increases in the ranges of disease
vectors.
- Although most studies focus on the period up to 2100, warming and sea
level rise are expected to continue for more than a millennium even if
greenhouse gas levels are stabilized.
- These basic conclusions have been endorsed by at least 30 scientific
societies and academies of science, including all of the national academies of
science of the major industrialized countries.
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Astro 100 |
Last updated: February 11, 2008 Neal Katz