Global Change 1. Global warminga. Today’s conditionsb. Greenhouse gasses“…delay the transfer of heat back into space, and re-radiation back to the lower atmosphere….”Carbon dioxide (CO2), Methane (CH4), Chlorofluorocarbons (CFC’s), Water vapor, etc.i. CO2 (Carbon dioxide)1. 64% responsible for global warming trend2. Since the industrial revolution (~1750s)3. Today, [CO2] is highest than in the last 420,000 yrs, and its growing rate is highest than in the last 20,000 yrs4. Global emissions of CO2a. Global emission in 2000 were 400% higher than in 1950. b. From 1980 to 1990 à1.5% c. From 1990 to 2000 à 0.6%d. In the US, since 1995 it arose 13%5.6.ii. CH4 (Methane)1. Responsible for 19% of total atmospheric warming2. Rate of 1% a yearà even higher than CO23. [CH4] are higher than in the last 420,000 yrs4. ~70% of CH4 emission come froma. Livestock farts and excrements b. Organic activity in flooded rice fieldsc. Burning of vegetation 5.2. Climate Modelsa. ~26 GCM around the worldb. Estimations for the next 100 yrs range from 1.3°C to 5.8°C (~2.2-10.4°F) temp increase3. Consequencesa. Food supplyi. Loss of 10% of soils’ humidityii. Greatest food securityà poor people, low-coast or in islandsb. Biospherei. Between 15-65% of forest à major species redistributionc. Diseasesi. Tropical diseases will migrate as well toward mid-latitudes (malaria, dengue, yellow fever, etc..d. Melting glacier & ice caps i. Loss of water resourcesà think of ecological, socio-economic, & cultural aspects4. Global
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