Page 280 - James Rodger Fleming - Fixing the sky

1. Reduce its production.
2. Adapt to increasing carbon dioxide and changing climate.
3. Remove it from the atmosphere.
4. Modify climate, weather, and hydrology.

The first two options, practiced worldwide, with foresight and moderation, con-
stitute the “middle course.” “Mitigation” properly refers to a complex array of
initiatives involving primarily decarbonizing and increasing the efficiency of the
energy supply, afforestation and the prevention of further deforestation, and
other efforts aimed at reducing anthropogenic emissions and concentrations of
radiatively active trace gases. “Adaptation,” or climate resilience, involves collec-
tive means taken to avoid, cope with, or reduce the adverse impacts of climate
change, both on humans and on all living creatures and ecosystems. The first
climate migrants in prehistorical times were adapting to the onset of an ice age.
Ward’s categories of prevention and protection, from 1930, are close matches.
Some mitigation efforts, however, involving proposed carbon capture and
sequestration can indeed be massive in scale, such as ocean iron fertilization and
a worldwide array of Lackner towers, and deserve the same caveats as direct cli-
mate intervention schemes.
In a 2008 book, Gabrielle Walker and Sir David King surveyed the prob-
lems of global warming and some of the technological and political “solutions,”
or at least responses that might arise. They discussed the oft-cited “stabilization
wedges” of Princeton professors Stephen Pacala and Robert Socolow, which
offered the hopeful vision of stabilizing atmospheric carbon dioxide levels (but
101
not necessarily the climate system) using existing technologies. Pacala and
Socolow rightly emphasized efficiency first—in electricity generation, passenger
vehicle transport, shipping, and other end-use sectors—followed by new renew-
able energy sources and as-yet-unproven carbon capture and storage. Walker and
King wrote that stabilizing atmospheric carbon dioxide levels at 450 parts per
million would require implementing the following “wedges” immediately:

Double the fuel economy of two billion cars, halve the annual average distance
traveled by two billion cars, cut carbon emissions from buildings and appliances
by one-quarter, capture and store carbon dioxide from 800 gigawatts of coal
power plants and 1600 gigawatts of natural gas power plants, build two million
1-megawatt wind turbines (about 50 times more than exist today), stop all felling
of tropical forests and plant 740 million acres of new trees in the tropics, double
the current amount of nuclear power, quadruple the amount of natural gas used to
generate electricity . . . , increase the use of biofuels in vehicles to fifty times today’s

tHe Climate enGineerS | 263