Figure 11.4 Atmospheric CO 2 , CH 4 , and N 2 O concentrations over the
last 2,000 years Increased ocean temperatures decrease the solubility of
gases in seawater (i.e., warmer water will release more CO 2 into the
atmosphere). Since oceans are one of the most important global carbon
sinks, absorbing a quarter of all atmospheric carbon dioxide emissions, the
oceans thereby over time become less effective in absorbing carbon dioxide
and other greenhouse gases as global temperatures increase. This results in
a dangerous positive feedback loop.
Greenhouse Gases by Source
Global greenhouse gas emissions can be broken down by the economic activities
that lead to their production.
■ AGRICULTURE—mostly comes from the management of agricultural soils
(e.g., deep plowing, livestock releasing methane gas, rice production,
slash and burn agricultural practices, and biomass burning).
■ COMMERCIAL AND RESIDENTIAL BUILDINGS—on-site energy generation and