Changing CO2 concentrations
¥CO2 concentrations have varied naturally by a factor of 2 over the past few hundred thousand
years
¥Fossil fuel burning since the industrial
revolution has created a
sharp increase in CO2 concentrations
¥CO2 concentrations are now higher than at any time in past few hundred thousand years
¥And concentrations are increasing faster
with time
Last 4 Ice Age cycles:
400,000 years
See http://epa.gov/climatechange/science/recentac.html
Man made
You are here
