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 What's
known for certain?
We know:
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that gases like carbon dioxide and methane
are greenhouse gases
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that we are increasing the amount of these gases into the atmosphere
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that much of this is due to burning fossil fuels
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that the CO2 in the atmosphere has increased
This graph shows
changes in the concentration (parts per million) of carbon dioxide
in the atmosphere over time. Carbon dioxide has built up rapidly
in the atmosphere since the beginning of the Industrial Revolution.
Levels are now more than 40 percent higher than they were in 1700.
What are the early warning signs ?
We know:
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that the Earth has warmed up
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there has been a warming of 0.50C ( 10F) in the
last 100 years
Warning signs include:
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heat waves
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sea level rising
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glaciers melting
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coastal flooding
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Arctic and Antarctic warming
What are we uncertain about ?
We do not know:
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