Human Impact on Ecosystems: Recent Climate

Change

Question:• The terms “Global

Warming” and “Global Climate Change” are used interchangeably in the media. Why are they not the same thing?

Global Warming:•The rise in Earth’s average global temperatures over the last hundred years.

Global Climate Change:

•The changes in climate and environmental conditions due to the rise in average global temperatures.

In 2007, the Intergovernmental Panel on Climate Change studied

years worth of data and concluded:

•Most of the temperature change was due to human activities

Question:•How do humans directly contribute to global warming and so to global climate change?

• Increasing release of greenhouse gases due to: –Burning of fossil fuels –Deforestation –Cattle production

Burning Fossil Fuels:•Oil, coal and natural gas•Used to:–Generate electricity–Heat homes–Run automobiles

Burning Fossil Fuels:•Produces greenhouse gases

which trap heat in the atmosphere:–CO2

–Methane (CH4)–Water vapor

Deforestation:• The cutting and burning of

forests to clear land for agriculture and development• Burning trees produces CO2

• Living trees remove CO2 from the atmosphere

Deforestation:• Food and Agriculture

Organization of the United Nations:–25% of CO2 released is the result of deforestation

Cattle Production:• Cattle produce or are the reason for the

production of 9% of greenhouse gases• More that automobiles.–Deforestation–What they are fed releases huge amounts

of gases. – So does manure.–30% of all arable (crop-growing) land is

used to grow feed for cattle

Aerosols:• Tiny liquid or solid particles in the

atmosphere–Reflect sunlight back into space–May cool climate in some areas.–Contributes to imbalances that

impact climate•Droughts, floods and weather

extremes

Environmental Impacts of rise in

average global temperatures:

Question:• Students often consider us

here in Colorado safe from the affects of rising sea levels. What would be the social and political impact on us as populations moved inland toward us?

Warming of Oceans:•Rising sea levels•More frequent

occurrences of El Niño and La Nina •More water in atmosphere

Warming of Oceans:•More energy in water and

atmosphere means more major storms•Hurricanes at sea•Thunderstorms on land•Blizzards

Warming of Oceans:•Changes in migration patterns of fish and birds•This is why Polar bears are beginning to starve.

Other Human Impacts on Ecosystems:

Question:•What other impacts do

humans have on their environment and how can groups and individuals make changes to lessen these impacts?

Resource Depletion:•Overuse of non-renewable resources•Fossil fuels and water

Resource Depletion:• Example: Oglalla Aquifer• Under the Great Plains• Used for irrigating farmland• Would have been gone by 2000

if efforts were not made to use water-saving irrigation methods.

Pollution:•Harmful or poisonous substances introduced into the environment

Examples:• Chlorofluorocarbons (CFC’s) used as

coolants in old refrigerators and air conditioners

• Damages the ozone layer, which protects the surface of Earth from harmful UV light.

• Use is now restricted world-wide, and ozone layer is increasing

Fossil Fuels:• Produces H2S and other acids when

burned–Creates acid rain–Dissolves metals, rock and concrete–Kills crops and trees

• Power plants and cars now have emissions controls as per the Clean Air Act of 1970

Ways to reduce our impact:•Reduce use of fossil fuels

–Nuclear energy–Wind and solar power–Hybrid and electric vehicles

Ways to reduce our impact:• Build more energy efficient

housing•Geothermal heat for homes

• Plant trees• Conserve energy and recycle

Food For Thought:•Nuclear energy can be dangerous•Chernobyl•Fukushima

Food For Thought:•Batteries, for computers

and cell phones, as well as electric cars use dangerous heavy metals which can increase pollution

Food For Thought:•So do the new energy efficient light bulbs

Video: Iron Eyes Cody (who was

really full-blooded Italian)