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

FIGURE 19-2 Future population

Projected carbon emissions:% increase = % increase in population x % change in emissions per person

x changes in efficiency of carbon use

Emission per personEfficiency 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 re-distribute 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 centuryCO2 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 concentration3. 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)

FIGURE 19-17 Larger temperature increases at high latitudes

The impacts of future increases of Greenhouse gases on humans

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