Climates Atlas 18,19 Textbook p18

Five Main Factors in Climates Latitude Winds Landforms (Orographic) Human Activity (Anthropogenic) Oceans

Global Climates: An Uncertain Forecast (cont.) World Climate Regions Weather: short-term, day-to-day expression of atmospheric processes Climate: long-term, average conditions At least 30 years of daily weather data (temperatures and precipitation)

World Climate Regions Knowledge of climate regions helps us make inferences about human activities and settlement. For example: a desert climate hampers agriculture; while adequate rainfall, warm temperatures permit farming.

Global Climates: An Uncertain Forecast (cont.) Global Climate Change Causes of Global Climate Change Natural greenhouse effect makes the earth warm enough to support life.

Increases in CO2 and Temperature Global Warming Causes of Global Warming (cont.) Anthropogenic (human caused) pollutants increase the greenhouse effect. Increases in CO2 and Temperature The graphs go back 1000 years and show both CO2 and temperature to have been relatively stable until the recent industrial period when the burning of fossil fuels (coal and oil) began on a large scale.

Global Climates: An Uncertain Forecast (cont.) Global Warming The Four Major Greenhouse Gases Carbon Dioxide (CO2): makes up more than 50% of anthropogenic greenhouse gases; comes mainly from burning fossil fuels Chlorofluorocarbons (CFCs): about 25% of human-generated greenhouse gases; come mainly from aerosol sprays, refrigeration, & air conditioning Methane (CH4): about 15%; caused by burning of vegetation, by-products of cattle & sheep digestion, leaking natural gas pipelines, and refineries Nitrous oxide (N2O): 5%; caused by agricultural chemical fertilizers

Global Climates: An Uncertain Forecast (cont.) Effects of Global Warming Computer models and scientists are coming to agreement on effects Average global temperatures will increase 2 °- 4 °F by 2030, and could double by 2100. Same magnitude of cooling that caused the Ice Age 30k years ago Major shift in agricultural areas Wheat belt could become warmer and drier; lower grain yield Canada and Russia could become warmer Southern regions of the U.S. and Europe could become warmer and drier, requiring irrigation Rising sea levels as polar ice-caps melt, endangering low-lying islands around the world, and coastal areas

A Climates page 18

Tropical Wet Climate (Af) The largest areas of Af climate occur in the upper Amazon basin of South America, the northern Republic of Congo (Zaire), and the islands of East Indies (Indonesia).

The single most descriptive word, can be that this tropical wet climate is monotonous. It is a season less climate, with endless repetition of the same weather day after day after day. Daily temperature variations are slightly greater than annual ones.

Tropical Monsoonal Climate (Am) Am type: m = monsoon, is most extensive on the windward (west-facing) coasts of southeastern Asia (India, Myanmar, and Thailand).

Tropical Savanna Climate (Aw) Tourism climates The most extensive of the A climates, the tropical savanna (Aw) w = winter dry; generally lies both to the north and to the south of the Af and Am areas. It occurs broadly in South America and southern Asia. To a lesser extent in northern Australia, Central America, and the Caribbean islands.

The distinctive characteristic of the Aw climate is its clear-cut seasonal alternation of wet and dry periods.

The high-sun season is wet , with one to four months receiving at least 10 inches of rain. The low-sun season is dry and a time of drought, sometimes three or four rainless months (Pacific Mexico resort towns).

B Climates (Desert Climate) Dry climates occur in both lower and higher latitudes. Most of the world’s arid areas have an enormous daily temperature range (especially in subtropical deserts.) Most desert are found near 22-30 degrees N and S and on leeward sides of mountains. There are two types of deserts BW (true deserts) BS (Steppe) which are wetter with up to 10 inches of rain per year.

C Climates (Humid Midlatitude/Humid Subtropical) Most C climates lie just beyond 30 degree north and south (Subtropical). These areas do not suffer the climatic extremes or severity, but the winters can be cold, especially away from large water bodies that moderate temperatures. You will find fertile and productive soils

There are 3 types of C climates Humid Subtropical/Midlatitude (eastern side of continents) Marine West Coast (moist) Mediterranean (dry summers)

D Climates (Humid Continental) Humid Cold (snow climates) -30 to 110 degrees, great annual temperatures. Some of the worlds most productive soils are found in this area Large landmass, High Latitude

Orographic Rainfall (Rain Shadow) Page 20

Orographic (p20)