NATS 1840 Lecture 22 – Global Warming
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Global warming and human impact on the environment
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Public debates, traditional liberal/conservative lines
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By 1980's scientific evidence for global warming strong, specifics hard to predict
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Global climate predictions, complex computer models
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Intergovernmental panel on climate change (ipcc), policy advice on global warming
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IPCC consensus on some of the most significant claims
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IPCC included input from political representatives
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Global warming as a political and environmental issue
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1990 IPCC report recommendations: efficiency, subsidies, reforestation, carbon sequestration
and new fuels
Resistance to Claims of Global Warming
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Fossil fuel industry lobbyists, questioned validity of global warming, costs of fighting it:
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Natural versus artificial temperature variations
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Computer models: varying predictions, sensitivity to input values, lack of specific
predictions
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Critiques of global warming did not appear in reputable scientific journals
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Media portrayed scientific controversy as widespread
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Lobbying in the US led to us government rejection of ipcc concerns
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Agreement on the general trend of warming, even if the details varied
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1991 explosion of mt. Pinatubo in the Philippines, sulphur dioxide (aerosol), global cooling,
prediction
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Computer models, data and accuracy
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1995 IPCC report: global temperatures rising, significant portion of this rise could be attributed
to human activities
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1997 kyoto meeting, reduction targets, fairness to late industrializers, economic costs
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Computer models and new data (e.g. water vapor, oceanographic temperatures, changes in
plant life), complexity
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If computer models are incorrect, things could be worse than we expect
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Regional predictions, long-term problem, short-term media and political interest
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Established interests versus younger generation
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Science is complex, uncertain and negotiated amongst professionals