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Global Climate SystemsI. Earth’s Climate

A. Past ClimateB. Present Climate and Classification

1. Climate components2. Classification 3. Köppen Climate Classification4. El Nino

III. Global Climate ChangeA. Global Warming

I. Earth’s Climate

Climate is weather over timeClimatology is the study of climateClimatic regions are areas with weather statistics that are similar over time

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Past Climate

How do we know about past climatic patterns?Glacial Ice DepositsBiological Marine SedimentsInorganic Marine Sediments Geological Proxy DataBiological Proxy Data

Past ClimateIce 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).

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Past ClimateWhy did the Ice Age occur?

• changing continental positions • reduction of CO2 in the atmosphere • changes in the Earth's orbit every 95,800 years

(Milankovitch Orbital Theory of Glaciation)

Past Climate

Columbian Mammoth

Dire Wolf

Saber Toothed Cats

Harlan’s Ground Sloth

American Lion

Short Faced Bear

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Earth’s Present ClimateClimate Components

Climate Components: InsolationTemperaturePressureAir MassesPrecipitation

Earth’s Present ClimateA. Climate Components

Precipitation

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Earth’s Present Climate A. Climate Components

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.

Earth’s Present Climate 2. Classification of Climatic Regions

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Earth’s Present Climate3. Köppen Climate Classification System

Weather data used to create the Köppen Climate Maps:Average monthly temperaturesAverage monthly precipitationTotal annual precipitation

Earth’s Present Climate3. Köppen Climate Classification System

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Earth’s Present Climate 3. Köppen Climate Classification System

Tropical Climates (A) – equatorial regions, humid, warm

Earth’s Present Climate 3. Köppen Climate Classification System

Dry Arid and Semiarid Climates (B) - deserts and steppes; arid and semiarid regions

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Earth’s Present Climate 3. Köppen Climate Classification System

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

Earth’s Present Climate3. Köppen Climate Classification System

Mediterranean Climates (Cs)

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Earth’s Present Climate 3. Köppen Climate Classification System

Microthermal Climates (D) – humid continental, subarctic regions

Earth’s Present Climate 3. Köppen Climate Classification System

Polar Climates (E) - polar regions

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Earth’s Present Climate 3. Köppen Climate Classification System

Highland Climates (H) – Found in areas with moderate to high temps., but temperatures here are low due to elevation.

Earth’s Present Climate 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.

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Earth’s Present Climate4. El Nino Southern Oscillation (ENSO)

Earth’s Present Climate4. El Nino Southern Oscillation (ENSO)

Gobal Climatological Effects of El Niňo

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Global Climate ChangeA.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 ChangeA. Global Warming

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Global Climate ChangeA. Global Warming

Radiatively active gases that influence global warming:

Carbon dioxide (CO2)Methane (CH4)Nitrous oxide (N20)Chloroflourocarbons (CFCs)Water vapor

Global Climate ChangeA. Global Warming

Impact of Global Warming:World food supply changesNatural ecosystems changesMelting glaciersIncrease in sea level

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Global Climate ChangeA. Global Warming

Figure 10.32

Antarctic Ice Disintegration

Global Climate ChangeA. Global Warming

Political Actions:Development of the Kyoto Protocol in 1997.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.