Making Reparation: Offset Your Life - Stolen Future, Broken Present: The Human Significance of Climate Change - page 140

why we might resist abandoning it, and what steps we could best take
within the actual limits of our lives. Thinking through this single example
may provide us with a template for how we can confront other destruc-
tive practices. Since air travel eventually will lead to the question about
whether to rely on carbon offsets to compensate for our flights, we might
also take up whether those offsets could work more broadly, whether
they might be a useful strategy in response to all the harm we do. In short,
this chapter will atempt to outline one practical approach to the chief
ethical challenges of our time.
In most discussions of how we might shift to a new energy econ-
omy, the topic eventually turns to air travel. In nearly every other area
of greenhouse gas usage, we can imagine a transition to alternative ener-
gies and can begin to make reasonable steps in that direction. But not
with air travel. As David MacKay points out, “planes are already almost
as energy-efficient as they could possibly be.” 126 Yet flying by plane has
an enormous, negative impact on the atmosphere. George Monbiot, in a
representative and remarkably clear discussion of the subject, citing the
research of the (British) Royal Commission on Environmental Pollution,
writes that “the carbon emissions per passenger mile 'for a fully loaded
cruising airliner are comparable to a passenger car carrying three or four
people.'” So far so good. But as Monbiot goes on to point out, “while the
mean distance travelled by car in the United Kingdom is 9,200 miles per
year, in a plane we can beat that in one day.” Planes are such an efficient
form of travel—they enable us to cover such huge distances so quickly—
we forget how much energy is required to move us so far. If the carbon
footprint of a given air mile doesn't seem so great, taking the full distance
into account expands that footprint very quickly.
But this isn't the half of it. The impact of travelling in airplanes,
Monbiot continues, “is not confined to the carbon they produce.”
Airplanes emit many different particles that have varying effects. The
IPCC thus estimates that the overall impact “is a warming effect 2.7 times
that of the carbon dioxide alone,” due primarily to the mixing of vapor
from jet engines with the air in the troposphere, creating the vapor trails
we can see from far below. “This means that subsonic aircraft, if all their
seats are full, cause roughly the same total warming per passenger mile
as cars.” 127