Changes in ClimateEarth Science

Mr. Barry

Ice AgesIce Age: period of

extensive glacial coverage, producing long-term climatic changes

Average global temperatures decrease by 5˚ C

Last Ice Age ended 10,000 years ago, covered northern USA plus parts of Europe and Asia

Short-Term ChangesSeasons: short-term

periods of climatic change caused by regular variations in daylight, temperature, and weather patterns

These changes are a result of the amount of solar radiation a location receives

Cause by tilting of the Earth as it revolves around the Sun

Short-Term ChangesEl Nino: warm ocean

current that develops off the western coast of South America that causes short-term climatic changes felt worldwide

Extended periods of rain cause warmer temperatures leading to heavier than usual rainfall and flooding in some areas

Natural ChangesClimate changes are

natural and have been occurring for many years

Solar Activity: sunspot cycles can cause warmer and colder temperatures on Earth

Earth’s Orbit: the Earth’s orbit goes from circular to elliptical over the course of a 100,000 year cycle

Natural ChangesEarth’s Wobble: over a

period of 26,000 years Earth wobbles as it rotates. This will eventually lead to a change in Earth’s seasons

Volcanic Activity: large amounts of ash get caught in the atmosphere, blocking the Sun and causing cooler than normal conditions

The Greenhouse EffectGreenhouse Effect:

natural heating of Earth’s surface by certain atmospheric gases, which helps keep Earth warm enough to sustain life

This is necessary for life to survive on Earth

Greenhouse Effect & Global WarmingAn increase in the Greenhouse Effect could

lead to temperatures in excess of what we could survive (470+˚ C)

The balance of the gases that cause the Greenhouse Effect (mainly CO2) is vital to regulating Earth’s temperature

Adding to the amount of greenhouse gases in the atmosphere can cause the overall average temperature of the Earth to rise

Global WarmingGlobal Warming: rise in global

temperatures due to increases in atmospheric CO2

Deforestation: removal of trees lowers the amount of organisms using CO2 to live, thus increasing the amount in the atmosphere

Burning Fossil Fuels: burning of fossil fuels releases CO2 as a waste product