The Greenhouse Effect
SPM 3
Concentration of Carbon Dioxide and Methane Have
Risen Greatly Since Pre-Industrial Times
Carbon dioxide: 33% rise
BW 5
The MetOffice. Hadley Center for Climate Prediction and Research.
Methane: 100% rise
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” +)
BW 7
Karl et al. 1996
Changes in rainfall
with doubled CO2
160
140
40°N
40°S
Australian
land
points
120
100
Change in
frequency
(%)
80
60
40
20
0
–20
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 >25.6
Daily rainfall class (mm day–1)
Melting of alpine glaciers
Melting of alpine glaciers
1941 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
CO2 emissions per capita
29
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
Global, 1990-2100
World
OECD
US
Brazil
Japan
China
India
0.8%
1.1%
1.4%
1.5%
2.7%
3.2%
4.3%
5.5%
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
Proposal for 2100 energy use
• Renewables (solar, wind, hydro) 50%
• Biomass 30% (5x present use)
• Nuclear phased out
• Fossil fuels 18% (down from 80%)
CO2 emissions (1990 -2100)
Mtc
7,000
6,000
5,000
4,000
3,000
2,000
1,000
0
1980
2000
2020
2040
Year
2060
2080
2100
2120
Global energy websites
World 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/