What are the causes of Climate Change?

The greenhouse effect is a natural phenomenon.

It has kept the earth at around 15oC, suitable for life to thrive, for over 3 billion years. CO2 is the main greenhouse gas.

Natural causes – ‘Sun spots’

Approximately every 11 years, the sun experienced increased activity, releasing more radiation (Sun Spots)

Natural causes - Volcanoes

• Eruptions release vast amount of greenhouse gases into the upper atmosphere

• Can lead to cooling in the lower atmosphere

Mt Pinatubu

• Released 20 million tonnes of sulphur dioxide into the atmosphere

• Average temperatures dropped by 0.2-0.5°c for several years

Natural causes - Volcanoes – Mt Pinatubo, 1991

Humans have added more greenhouse gases to the atmosphere mainly by burning fossil fuels. This has added more CO2 to the atmosphere causing more warming (nearly 1oC in the last 100 years).

Human causes

Various human activities increase greenhouse gases.

•Burning fossil fuels (CO2)

•Cement manufacture (CO2)

•Deforestation (CO2)

•Rice production (methane)

•Digestion of grass by cattle (methane)

•Domestic sewage and landfill (methane)

•Industry (CFCs etc)

Human causes of climate change

By 2100: scientists predict …

Between 2 and 6oC rise in temperature!

What will be the effects of this the planet?

Top 10 BIGGEST effects of

global warming

1. Extinction of plants and animals

2. Destruction of ecosystems

3. More extreme heat waves

4. Sea level rise

5. Spread of disease

6. Drought

7. War

8. Shrinking glaciers

9. More storms and floods

10. Economic hardship

Task…

Draw a BIG mind map showing people:

The effects of climate change.(remember the domino effect…)

http://www.direct.gov.uk/en/Environmentandgreenerliving/Thewiderenvironment/Climatechange/DG_072929Next = Solutions … use Horizons p90-91.