Geoscience Reference
In-Depth Information
At present, there have been no large-scale geoengineering experi-
ments on our globe (other than volcanoes themselves), so the estimates
of its impacts and side effects are based on computer modeling. The major
concern is that geoengineering is not really a perfect offset to the green-
house effect. The little particles or mirrors would reduce incoming
radiation while the greenhouse effect decreases outgoing radiation. The
two effects might lead to zero net warming, but they are very different
physically.
A useful analogy is turning on your home air conditioner during a
heat wave. Perhaps your house will be, on average, the same tempera-
ture as on a normal day, but some of the rooms might be colder and
others warmer, and you defi nitely will be spending a small fortune on
electricity.
So what are the net effects of combined CO
2
warming and “little
mirror” cooling? Here is a summary of current fi ndings: It will defi -
nitely not solve the problem of ocean acidifi cation because altering the
earth's energy balance has little impact on atmospheric CO
2
concentra-
tions. The results of climate modeling to date suggest that at the right
dosage, the planet could be cooled to present levels by injection of re-
fl ective particles into the atmosphere. However, modeling suggests
some important side effects. One effect that is predicted by fundamen-
tal physics and confi rmed by modeling is a general decrease in precipi-
tation. In other words, it does not seem possible to return to the current
temperature and precipitation patterns with CO
2
elevation and geoen-
gineering. One study found that using enhanced stratospheric aerosols
would modify the Asian and African summer monsoons.
4
Additionally, active climate management may create a whole new
set of political problems. In today's world, where everyone is guilty of
causing global warming, no one can be held responsible. However, if
certain countries engage in active climate management, then affected
parties can point the fi nger at them if some undesirable weather pattern
emerges. This means that any responsible geoengineering program will
need to be negotiated among countries, and it might require some kind
of compensation scheme if some regions are damaged.
