Geoscience Reference
In-Depth Information
defi nitely cannot reduce our carbon emissions to zero by reduc-
ing our consumption by fi fty or ninety percent.
• Reduce the carbon intensity of production of goods and services.
This would involve changing the
how
rather than the
what
of pro-
duction processes. For example, we might substitute natural gas
for coal in electricity generation, which would reduce CO
2
emis-
sions by about half. Or we might go even further and use zero-
carbon wind generation. Studies indicate that the real gold is likely
to be found here—in changing production technologies and pro-
cesses, particularly when we develop low-carbon technologies.
And maybe some miraculous, unheard-of technology will be dis-
covered that will produce our energy not only without carbon but
also less expensively than current fuels.
• Remove carbon from the atmosphere. A fi nal approach is post-
combustion CO
2
removal. There are several strategies here, but
most look expensive and massive in scale, as will be discussed later.
I do not discuss the details of these approaches. They have been ana-
lyzed by experts on many occasions, and readers can look to those for
the balance of this chapter: a short-run example of fuel switching; a sec-
ond example of postcombustion removal; and then some futuristic ex-
amples. The fi nal section discusses the way that potential technological
breakthroughs enter the analysis in the context of the Climate Casino.
Natural gas is the cleanest of the fossil fuels, emitting about half as
much CO
2
per kilowatt hour (kWh) as coal when burned for electricity
generation. Shifting a greater fraction of electricity to natural gas is an
important way of reducing CO
2
emissions. According to expert reports
(see Table 14), new natural gas combined-cycle power plants produce
electricity less expensively than new coal plants. For example, the total
cost of electricity from a new conventional coal plant is estimated to be
about 9.5 cents per kWh, while the total cost from a natural gas station
is estimated to be 6.6 cents per kWh. At the same time, the CO
2
emis-
sions per kilowatt hour from a coal plant are approximately double
those from a natural gas plant.
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