The Greenhouse Effect

SPM 3

Concentration of Carbon Dioxide and Methane Have Risen Greatly Since Pre-Industrial Times Carbon dioxide: 33% riseMethane: 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 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 BW 7

Changes in rainfall with doubled CO 2 >25.6 Daily rainfall class (mm day –1 ) – Change in frequency (%) 40°N40°S Australian land points

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 CO 2 emissions, change economy World-wide shift to non-fossil energy Increased energy efficiency

29 CO 2 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

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%)

Mtc 0 1,000 2,000 3,000 4,000 5,000 6,000 7, CO2 emissions ( ) Year

Global energy websites World Resources Institute World Energy Council World Energy Assessment UN Development Program