The Greenhouse Effect

SPM 3

Concentration of Carbon Dioxide and Methane Have Risen Greatly Since Pre-Industrial Times

Carbon dioxide: 33% rise Methane: 100% rise

The MetOffice. Hadley Center for Climate Prediction and Research.

BW 5

Variations of the Earth’s surface temperature for the past 140 years

SPM 1a

Variations of the Earth’s surface temperature for the past 1,000 years

SPM 1b

Certainties

• Existence of natural greenhouse effect

• Greenhouse gases increasing

• Temperature increasing – 1998 the hottest in at least 1000 years.

• Sea levels rising – 4 -10” over century

Uncertainties

• Timing of atmospheric warming, glaciers

• The effects of increased cloudiness

• Uneven health and ecological impacts

• Unanticipated events

Effects of global warming

People at Risk from a 44 cm sea-level rise by 2080

Assuming 1990s Level of Flood Protection

Source: R. Nicholls, Middlesex University in the U.K. Meteorological Office. 1997. Climate Change and Its Impacts: A Global Perspective.

Sea-level transgression scenarios for Bangladesh

Adapted from Milliman et al. (1989).

Forest fires in drying forests

Percent of USA with above normal proportion of total annual precipitation from -day extreme events (2” +)

Karl et al. 1996

BW 7

Changes in rainfall with doubled CO2

>25.6

Daily rainfall class (mm day–1)

0.2-0.4 0.4-0.8 0.8-1.6 1.6-3.2 3.2-6.4 6.4-12.8 12.8-25.6

160

140

120

80

60

40

20

0

–20

100

Change infrequency

(%)

40°N 40°SAustralianlandpoints

Melting of alpine glaciers

Melting of alpine glaciers1941 and 2004

Melting of ice caps

Melting of sea ice,

permafrost

Other impacts

• Tropical diseases, insects move north

• Loss of agricultural land

• End of ecosystems that cannot shift

Future goals?

• Reduce CO2 emissions, change economy

• World-wide shift to non-fossil energy

• Increased energy efficiency

29

CO2 emissions per capita

1997 Kyoto Protocol

• Cut gases to under 1990 levels by 2012

• China, India exempted for present

• Europeans met most goals

• U.S. would have to cut energy use 40%;

Bush withdrew 2001

Energy growth rates

5.5%

4.3%

3.2%

2.7%

1.5%

1.4%

1.1%

0.8%

India

China

Japan

Brazil

US

OECD

World

Global, 1990-2100

Conservation• Homes

– insulation, less heat, efficient appliances

• Vehicles – Drive less, higher mpg

• Industry– Less waste, renewable and efficient energy

• Land use– More tress (carbon sinks), no sprawl

0

5,000

10,000

15,000

20,000

25,000

1990 2020 2050 2100

SolarHydroBiomassNuclearN. GasCoalOil

Proposal for 2100 energy use

• Renewables (solar, wind, hydro) 50%

• Biomass 30% (5x present use)

• Nuclear phased out

• Fossil fuels 18% (down from 80%)

Mtc

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

1980 2000 2020 2040 2060 2080 2100 2120

CO2 emissions (1990 -2100)

Year

Global energy websitesWorld Resources Institute

www.wri.org

World Energy Council

www.worldenergy.org/

World Energy Assessment

www.undp.org/seed/eap/activities/wea/

UN Development Program

www.undp.org/seed/eap/