Impacts of Climate Change and their mitigation Bill Menke October 6, 2005.
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Transcript of Impacts of Climate Change and their mitigation Bill Menke October 6, 2005.
Most of this material drawn fromIPCC REPORTS
I’ve saved a copy at my web site …
www.ldeo.columbia.edu/users/menke/data/ipcc/index.html
You should read the technical summaries … at least !
Note that global temperatureis predicted to increase by as
much as little as1 deg C
or as much as5 deg C
in the next centurywith most models in the
2-4 deg Crange
Hydrologic Cycle: Note land precipitation of 108,000 km3
And that 58% evaporates, with the rest, 46,000 km3,flowing in rivers. But only about 5000 km3 are usable foragriculture
Typical land, about 1 meter (40”) of precipitation, 42% (17”) is runoff
Now increase temperature 3 deg C (5.3 F),runoff decreases to 14.5”, a drop of 15 percent
3 deg C
Model that takes into account overall climate changes alsoPredicts regions (e.g. in red) where runoff is down by 15%
Food From WaterCaloric need: 2000 kCal per person per dayGrain: 4000 kCal per kg6 Billion People on earthWater needed to grow that grain: 1 m3 per kg
Putting it all together, agriculture requires
1100 km3 of water per yearas long as we’re all vegetarians