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Chap. 19: Climate Change in the next 100 to 1000 yrs
Natural Variations in Climate
FIGURE 19-1 Greenhouse and natural changes
Future Human Impacts on Climate
Projected carbon emissions:
% increase = % increase in population x % change in emissions per person
x changes in efficiency of carbon use
FIGURE 19-2 Future population
Emission per person
Efficiency of use: oil, gas, coal (anthracite coal, bituminous coal)
new technology and affordability
FIGURE 19-3 Projected carbon emissions
Projected CO2 concentrations in the atmosphere
How the climate
system will redistribute the pulse of
excess CO2 among its
carbon reservoirs?
½ of the total carbon
emission enter the
ocean and the
biosphere?
FIGURE 19-4 The fate of the human CO2 pulse
Decline of CO2 concentration lags peak of emisison by a century
CO2 concentration above the pre-industrial level 1000yrs later
FIGURE 19-5 Projected CO2 concentrations
Other human effects on the atmosphere
BOX 19-1 Methane clathrate feedback (a frozen form, CH4 mixture with slushy ice)
Future Climate Change Caused by increased CO2
1. Excess CO2 emission; 2. Excess CO2 concentration
3. Earth sensitivity to higher CO2 concentration
FIGURE 19-6 Projected temperature increases
Partial analogs from Earth’s history
FIGURE 19-7 CO2: past and future
FIGURE 19-8 Temp: past and future
FIGURE 19-9 A 2xCO2 world The 2xCO2 world likely to exist by the year 2100
will in many ways be similar to the world that existed 5 to 10 million yrs ago
FIGURE 19-10 Melting permafrost
FIGURE 19-11 The Greenland ice sheet
FIGURE 19-12 The Antarctic ice sheet
FIGURE 19-13 Vulnerable ice shelves?
FIGURE 19-14 A 4xCO2 world
The 4xCO2 world that may come into existence between
2200 and 2300 would be slowly moving toward conditions that existed 50 or more million yrs ago,
when little or no glacial or sea ice was present on Earth, and forests grew in the higher latitude of
the Artic.
Greenhouse surprises?
Melting of Greenland ice
Stop formation of deep water
Colder Europe (5oC or more)
Slow or stop the rate of uptake of CO2 in N.
Atlantic
Extra CO2 remain in the atmosphere
Others ?
Monitoring Greenhouse Warming: the next few decades
FIGURE 19-15 Future changes in ice volume
FIGURE 19-16 Future changes in subsurface ocean temperature Measuring
increases in the height of the ocean caused by thermal expansion and
increases in the velocity of sound moving through subsurface ocean layers (A
SOund Fixing And Ranging Channel located at a depth near 1 km is particularly
favorable)
The impacts of future increases of Greenhouse
gases on humans
FIGURE 19-17 Larger temperature increases at high latitudes
FIGURE 19-18 Changes in length of seasons
Value Judgments
Changes in regional temp.
Changes in water for civil usage, agriculture
Rise of sea level
Epilogue