DEALING WITH CLIMATE CHANGE: ADAPTATION AND GEOENGINEERING - The Climate Casino - page 151

and build irrigation systems. If heat waves become more frequent, then
people can install air conditioning. In some situations, adaptation might
reduce the impacts to virtually nothing. In other cases adaptation may
accomplish very little.
Adaptation is seldom costless, however. Farmers have to invest real
money when they install and operate irrigation systems to adapt to a
drier climate. You and I will have to put out cash to install and run air
conditioners. But, for the United States, at least, estimates suggest that
adaptation to modest climate change (say, an increase of 2-3°C) will off-
set most of the potential damage to humans and their enterprises. 1
In still other areas, including unmanaged or unmanageable sys-
tems such as ocean acidifi cation, sea-level rise, and threatened species
and ecosystems, the necessary adaptations are extremely costly or im-
possible. Let's take a fl ight of fancy for sea-level rise. Someone might
propose that we adapt by pumping the excess seawater on top of Ant-
arctica to prevent sea-level rise. Some calculations indicate that this
would require pumping 800,000,000,000,000,000 gallons per year and
would be astronomically expensive. 2 Similarly, we might try to store
the DNA of threatened species until new biotechnologies could regener-
ate them, but there is no guarantee that we will actually be able to per-
form this task. So if one takes unmanaged or unmanageable systems
into consideration, adaptation is at best an incomplete solution to the
vast changes that are likely to occur in the coming centuries.
Specialists here make two fundamental points about adaptation.
First, adaptation is local while prevention is global. We prevent climate
change by reducing global emissions and concentrations. It does no
good if you or I reduce our emissions while the rest of the world contin-
ues its energy business as usual. On the other hand, adaptation is local
because the costs and benefi ts accrue to the people who undertake the
adaptation. If a farmer changes crops or installs an irrigation system,
the farmer pays for the adaptation and the farmer also benefi ts from it.
If I move my sea-front cottage to higher ground to reduce the threat
from hurricanes, I pay and I benefi t. These examples are oversimplifi ed
because of realistic complications such as government subsidies, im-
pacts on neighbors, and market distortions, but these are complicating