Global Climate Systems

Transcription

1 Global Climate Systems I. Earth s Climate A. Past Climate B. Present Climate and Classification 1. Climate components 2. Classification 3. Köppen Climate Classification 4. El Nino III. Global Climate Change A. Global Warming I. Earth s Climate Climate is weather over time Climatology is the study of climate Climatic regions are areas with weather statistics that are similar over time 1

2 Past Climate How do we know about past climatic patterns? Glacial Ice Deposits Biological Marine Sediments Inorganic Marine Sediments Geological Proxy Data Biological Proxy Data Past Climate Ice ages are intervals of time when large areas of the surface of the globe are covered with ice sheets (large continental glaciers). Most recent Ice Age occurred during the Pleistocene (2,000,000 to 14,000 years ago). 2

3 Past Climate Why did the Ice Age occur? changing continental positions reduction of CO 2 in the atmosphere changes in the Earth's orbit every 95,800 years (Milankovitch Orbital Theory of Glaciation) Past Climate Columbian Mammoth Short Faced Bear Dire Wolf Harlan s Ground Sloth Saber Toothed Cats American Lion 3

4 Climate Components Climate Components: Insolation Temperature Pressure Air Masses Precipitation A. Climate Components Precipitation 4

5 A. Climate Components 2. Classification of Climatic Regions Types of Climate Classification: Genetic classification: Classification based on causative factors (things like air masses and global circulation) Empirical classification: Classification based on temperature and precipitation data. 5

6 Weather data used to create the Köppen Climate Maps: Average monthly temperatures Average monthly precipitation Total annual precipitation 6

7 Tropical Climates (A) equatorial regions, humid, warm Dry Arid and Semiarid Climates (B) - deserts and steppes; arid and semiarid regions 7

8 Mesothermal Climates (C) humid subtropical, Mediterranean, and marine west coast regions Mediterranean Climates (Cs) 8

9 Microthermal Climates (D) humid continental, subarctic regions Polar Climates (E) - polar regions 9

10 Highland Climates (H) Found in areas with moderate to high temps., but temperatures here are low due to elevation. 4. El Nino Southern Oscillation (ENSO) Occurs when in air pressure over the Pacific changes causing the trade winds to change direction. Water intensification and thunderstorms are in turn brought to the west coast of continents. Occurs every 3-5 years. 10

11 4. El Nino Southern Oscillation (ENSO) 4. El Nino Southern Oscillation (ENSO) Gobal Climatological Effects of El Niňo 11

12 Global Climate Change A.Global Warming Refers to short-term increases in global temperatures caused by human actions. Forced fluctuations in climate change are due to human activities. Unforced fluctuations are natural changes in global climate. IPCC states that global warming can be attributed to human activities (forced fluctuations). Global Climate Change A. Global Warming 12

13 Global Climate Change A. Global Warming Radiatively active gases that influence global warming: Carbon dioxide (CO 2 ) Methane (CH 4 ) Nitrous oxide (N 2 0) Chloroflourocarbons (CFCs) Water vapor Global Climate Change A. Global Warming Impact of Global Warming: World food supply changes Natural ecosystems changes Melting glaciers Increase in sea level 13

14 Global Climate Change A. Global Warming Antarctic Ice Disintegration Figure Global Climate Change A. Global Warming Political Actions: Development of the Kyoto Protocol in Forces more developed countries to reduce greenhouse gas emissions collectively by 5.3% United States goal of 7.0% will not be met because President Bush has abandoned the Kyoto Protocol under concerns for the economic cost of the emissions reduction. 14