Greenhouse Gases
Original Source:
In 1958 John David Keeling began monitoring CO2 concentrations at the US
Weather Bureau observatory on Mauna Loa, Hawaii. This now-famous
“Keeling Curve” shows his data from that starting data (315 ppm) to the present
date (387 ppm), as well as, the annual cyclical variation of CO2 concentrations due
to seasonal photosynthesis (CO2 sink) and decomposition (CO2 source).
Global Carbon Emissions 2004
How much CO2 is too much? Climate experts are now evaluating certain
planetary system to determine if “tipping points” have been reached .