Climate Change and Human Impact

Many natural processes cause climate change

• Volcanic eruptions – volcanic ash and dust in the atmosphere reflect solar energy and can lower temperatures

• These are short-term changes

• Ocean circulation – changes in ocean circulation cause short-term changes in precipitation (El Niño and La Niña)

• Solar activity – sunspots have been connected to warm periods in Europe and North America

• Earth motions – Plate movements and changes in the Earth’s tilt and orbit cause large climate changes

• changes are long-term

How do humans impact the environment?

• Humans have a large impact on the environment and the organisms we share it with.

• This is due to our–Increasing population size.–Increasing use of both renewable

and non-renewable resources.

The Carbon Cycle• Cycling of carbon through the environment

mainly in the form of CO2 and carbohydrates.

What processes remove carbon dioxide from the atmosphere?

• Photosynthesis by land and aquatic autotrophs

• Precipitation onto land & ocean

What processes release carbon dioxide into the atmosphere?

• Cellular respiration by all organisms• Decomposition of organisms• Volcanic activity• Human activities

What stores carbon dioxide?

• Limestone (calcium carbonate) rock• Decomposition of organisms and

their conversion into fossil fuels• Diffusion of carbon into the ocean

The Carbon Cycle

http://www.windows.ucar.edu/earth/climate/images/carboncycle.jpg

Human Activity and the Carbon Cycle

• Human activity causes the release of CO2 at a much faster rate than it is absorbed.

• This is due to:–Clear-cutting and burning forests for

housing and farming–Burning fossil fuels

• These activities have resulted in a global climate change .

What is the Greenhouse Effect?• Works like a car in the summer. Sun

passes through, hits a surface and changes to heat. Heat is trapped.

What is the Greenhouse Effect?

• The greenhouse effect is the natural warming of Earth due to certain gases in the atmosphere trapping out-going heat energy.

• Greenhouse gases - water vapor, carbon dioxide, & methane

Global Warming

http://www.darlington.gov.uk/NR/rdonlyres/2091F156-0B6A-456B-B5FA-24579F372F36/0/greenhouseeffect.jpg

So then what is Global Warming?

• The Greenhouse Effect and Global Warming are NOT the same thing!!!

• Global Warming is the increase in the average measured temperature of the Earth's near-surface air and oceans.

• Global Warming affects the Greenhouse Effect.– Greenhouse Effect = GOOD– Global Warming = BAD

What are the Possible Effects of Global Warming?

http://www.greatdreams.com/flood/flood-antigo-2004b.jpg

http://www.michigan.gov/images/mosquito_65147_7.jpghttp://www.nytimes.com/2007/07/04/us/04drought.html?_r=1&oref=slogin

These include:• Flooding of coastal areas.• Increased spreading of disease.

• Drought across inland areas.