Upp í vindinn - 01.05.2016, Blaðsíða 14

Nuclear Energy,
Climate Change
and Air Pollution
In recent years there has been greatly
increased worldwide awareness of
the urgency of the human-caused
global climate change and air
pollution crises. Premature deaths
frorn global outdoor air pollution, for
example, are assessed to be of the
order of 3 million annually, with the
majority occurring in South
and East Asia.1
Fossil fuel use is the overwhelming
cause of both climate change and
air pollution2, and mitigation efforts
for both of these problems should be
undertaken concurrently in order to
maximize effectiveness. Fortunately,
such efforts can be accomplished
largely with currently available clean
(i.e. non-fossil) energy sources like
nuclear power and renewables (solar,
wind, geothermal, hydropower,
etc), along with energy efficiency
improvements. However, various
barriers to achieving these goals
persist, including lack of meaningful
action by govemments and, in some
cases, major misconceptions among
the public.
Many governments and
environmental groups/individuals
consider renewables to be virtually
problem-free, while nuclear is
considered intractably problematic.
Both of these views contravene
the conclusions of comprehensive,
scientific assessments, such as
those recently conducted by the
Intergovernmental Panel on Climate
Change (IPCC) and the Global
Energy Assessment3. These analyses
and many others indicate very clearly
that there are no perfect energy
sources, and that all clean energy
sources (including nuclear) will
need to be massively and rapidly
expanded in order to achieve climate
and air pollution mitigation targets.
Thus, the long-standing tendency
to disproportionately focus on the
drawbacks of nuclear power is highly
counterproductive.
Several recent scientific studies have
tried to counteract this tendency
by taking an objective, big-picture
approach. For instance, in March
2013 I published a peer-reviewed
scientific paper4 in a major journal
(co-authored by world-renowned
climate scientist Jim Hansen) that
examined one basic question: If
nuclear power never existed, what
would the human health and climatic
implications have been?
Pushker A. Kharecha, PhD
Climate Scientist
Columbia Earth Institute and NASA
Goddard Institute for Space Studies
We addressed this question
by first realizing that, for both
technological and econonric
reasons, the replacement energy
source would have been almost
entirely coal, along with a small
contribution from natural gas. We
then analyzed historical (1971-
2009) and projected (2010-2050)
nuclear energy production data
for global and regional/national
scales. We found that over the
last 40 years, nuclear energy use
prevented an average of about 2
million air pollution-related deaths
globally due to its displacement
of fossil fuel use (Figure la).
This is many thousands of times
higher than the number of deaths
it caused. Furthermore, we found
that nuclear power has prevented
over 60 gigatonnes of global carbon
dioxide emissions (Figure 2a) -
equivalent to the emissions from the
past 30+ years of U.S. coal burning,
or the emissions from hundreds of
large coal-fired power plants. Our
analysis also shows that over the next
few decades there would be even
greater prevented human health and
environmental impacts from global
expansion of nuclear energy if it
displaces future fossil fuel use - on