Environmental Engineering Reference
In-Depth Information
Technical Note
.
: Carbon Dioxide Equivalents
Different greenhouse gases have stronger or sometimes
weaker effects on global warming than CO
. The modelers
work in terms of CO
equivalents or CO
e. For example,
CH
(natural gas or methane) is
times stronger as a
greenhouse gas than CO
. If I emitted
tonnes of CO
and
tonnes of natural gas, the CO
e of the combination is
the same as adding the emission of
tonnes of CO
(the
CO
equivalent of
tonnes of CH
)
to the original
. There are other gases that are even
stronger than natural gas. Carbon tetra
tonnes of CO
uoride, used in
microelectronics fabrication, is
times as strong a green-
house gas as CO
. Fortunately, we emit very little of it.
Table
IPCC Summary for
Policymakers. It gives the annual emission of the main
greenhouse gases in gigatonnes (billions of metric tonnes)
of CO
.
shows data from the
equivalents (CO
e).
Table
of the main greenhouse
gases in gigatonnes of CO
equivalent, removal time, and
percentage of each in the total
.
Global emissions in
CO
equivalent
(Gt)
Removal
time (years)
Percentage
of total
Gas
CO
(fossil fuel)
.
>
CO
(other
industrial)
.
>
CO
(agriculture)
.
>
CH
(agriculture
and industry)
.
N
O (agriculture)
.
Fluorine gases
.
Total
