“GAME OVER” - The Power Surge: Energy, Opportunity, and the Battle for America's Future - page 86

production is more to be celebrated or feared. h e questions that need
to be answered in order to make that sort of judgment are dif erent.
Two come down to a mix of climate science and moral judgment: How
sensitive is the earth's climate to rising greenhouse gas concentrations?
How bad will the consequences that result from global warming be?
(h is second question has a big moral component: How much should
we care about bad consequences that will occur outside the United
States or to future generations?) Another two lie more in the realm
of economics and politics. How much will developing U.S. oil and
gas contribute directly to global greenhouse gas emissions? Moreover,
human-caused climate change is a product of emissions from around
the world, not just the United States. Given that, what does higher U.S.
oil and gas production really mean for emissions and climate change
writ large?
Much of the debate over how touchy the earth's thermostat is
revolves around a number known as climate sensitivity. h is is typi-
cally expressed as the amount of warming we should expect to see if
atmospheric concentrations of greenhouse gases were to double from
their preindustrial levels. It is widely agreed that the direct impact is
relatively small, but big questions arise when you start looking at more
complex dynamics, particularly those that unfold over longer periods
of time. A big part of the debate focuses on what happens to clouds:
as temperatures rise because of higher greenhouse gas concentrations,
clouds start to behave dif erently; depending on whom you ask, this
could suppress warming slightly (these days a minority position) or
enhance it moderately (the dominant view). Another area of contention
revolves around what will happen to Arctic ice. As the planet warms, ice
melts, and white slabs make way for dark blue seas. Dark colors absorb
much more energy from the sun than white ones do (something that
anyone who has gone outside on a hot day wearing black knows). h e
Arctic seas, now much darker than before, trap more heat, leading to
more warming. Feedbacks such as this one, which can play out over
many years, can boost climate sensitivity well beyond what short-term
dynamics would do.
With so many moving pieces, it should be no surprise that estimates
of climate sensitivity are all over the map. h e most authoritative survey