2. Average temperature changes Earths temperature increased by 1.5ºF during the 20 th century-Projections for warming suggest a global increase of 2.5ºF - 10.4ºF by 2100 10 warmest years of the last century all occurred with the last 15 years 2001, 2002 and 2003 were three of the hottest years ever recorded How can we know past climate? Data from Dome C, Antarctica, ice core -Estimates of Temp. from hydrogen isotopes -Measurements of greenhouse gases (CO 2 ) -Estimates of Temp. from oxygen-18 (fossil marine shells) -Fossils (Plants, animals) How do we know what to expect?

3. Predicted Changes: ~Temperature & Precipitation increase ~Melting glaciers -Rise in sea level -10-20 cm in 20th century ~Coastal Areas -Amplified storm surges -Damaged coastal infrastructure (roads, etc.) -Salination of fresh-water -Population displacement -Beach erosion -Ecosystem Loss ~Forests -tropical, temperate, & boreal, -Change in forest composition -forest productivity ~Biodiversity (i.e. Coral reefs) -Loss of habitat and species ~Agriculture -Food shortages -Crop failures -Irrigation demands ~Water -Water quality -Competition for water resources ~Weather extremes -Storms -Floods -Drought -Hurricanes

4. Health effects ~Extreme weather related -floods, storms, tornados ~Air pollution related health effects -aggravated asthma, bronchitis, emphysema, lung and heart diseases, and respiratory allergies ~Diseases: -Mosquitoes that spread malaria, yellow fever, dengue, etc. could live in USA. ~Temperature related illness and death -heat waves: heat stroke, heat exhaustion, Predicted Changes cont.: