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Points
Of Agreement |
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Main
Point of Contention |
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Prediction Of the Future Warming |
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Global climate change, including global warming,
are inevitable should the atmospheric concentration of greenhouse gases
rise continually. (They disagree about the timing and magnitude of the
warming). |
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The atmospheric concentration of greenhouse
gases is rising. |
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The debate about global warming is primarily
about the degree to which different feedbacks will influence the Earth’s
climate in the future. |
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Many of those feedbacks involve water in one
form or another. |
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Water Vapor Feedback - Positive |
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Snow/Ice Albedo Feedback - Positive |
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Longwave Radiation Feedback - Negative |
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Vegetation-Climate Feedback - Positive |
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Cloud Feedback - Uncertain |
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The global warming observed in the past 100
years can be a result of natural variability and anthropogenically induced. |
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Since our understanding of the natural
variability is limited, it is difficult for us to decide whether or not the
human-induced global warming already shows up. |
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The detection of the current anthropogenically
induced signal will be difficult until it is very large. |
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If the atmospheric level of greenhouse gases
continue to rise at the present rate, climate models predicts: |
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Very Probable |
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Global surface temperature will warm up 0.5-2°C
over the period 1990 to 2050. |
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Global sea level will rise by 5 to 40 cm by
2050. |
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Global precipitation will increase |
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Arctic land areas will experience wintertime
warming |
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Probable |
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Rainfall will increase over the high latitude of
the northern hemisphere, but will decrease in the midlatitude of northern
hemisphere continents. |
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Uncertain |
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We are not sure how climate will change in small
regions |
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We are not sure how the frequency of El Nino
will change |
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We are not sure how hurricane, flood, and
drought will respond to global warming |
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