ESS11
Prof.
Jin-Yi Yu
Increase of CO2 Concentration
qThe atmospheric
concentration of carbon dioxide (CO2) has increased by 31% since 1750. The present CO2 concentration has not been exceeded during the
past 420,000 years and likely not
during the past 20 million years. The current rate of increase is unprecedented during at least the past 20,000
years.
qAbout three-quarters of the anthropogenic
emissions of CO2 to the
atmosphere during the
past 20 years is due to fossil fuel burning.
The rest is predominantly due to land-use change, especially deforestation.
qCurrently the ocean
and the land together are taking up about half of the
anthropogenic CO2 emissions.
On land, the uptake of anthropogenic
CO2 very likely exceeded the release of CO2 by deforestation during the 1990s.