by Peter Reuell
Harvard Staff Writer
February 19, 2013
File photo by
Kris Snibbe/Harvard Staff Photographer
Global climate change, extreme weather, and national security are
according to a study
co-authored by Harvard Professor Michael McElroy (pictured)
and D. James Baker, a
former administrator of the National Oceanic and Atmospheric
A Harvard researcher is pointing toward a new reason to worry about
the effects of climate change - national security.
A new report (Climate
Extremes - Recent Trends with Implications for National Security)
the Gilbert Butler Professor of Environmental Studies, and D.
James Baker, a former administrator of the National
Oceanic and Atmospheric Administration
global climate change
the next decade, the report concludes, climate change could have
wide-reaching effects on everything from food, water, and energy
supplies to critical infrastructure and economic security.
the last century, the trend has been toward urbanization - to
concentrate people in smaller areas,” McElroy said.
“We’ve built an infrastructure - whether it’s where we build our
homes or where we put our roads and bridges - that fits with
that trend. If the weather pattern suddenly changes in a serious
way, it could create very large problems. Bridges may be in the
wrong place, or sea walls may not be high enough.”
effects on critical infrastructure, however, only scratch the
surface of the security concerns.
On an international scale, the report points to recent events, such
as flooding in Pakistan and sustained drought in eastern Africa,
that may be tied to changing weather patterns.
United States responds to such disasters - whether by delivering
humanitarian aid or through technical support - could affect
recognizing the immediacy of these risks, the U.S. can enhance
its own security and help other countries do a better job of
preparing for and coping with near-term climate extremes,” Baker
report suggests that climate changes could even have long-reaching
It’s possible, McElroy said, that climate changes may have
contributed to the uprisings of the Arab Spring by causing a rise in
food prices, or that the extended drought in northern Mexico has
contributed to political instability and a rise in drug trafficking
in the region.
don’t have definitive answers, but our report raises these
questions, because what we are saying is that these conditions
are likely to be more normal than they were in the past,”
“There are also questions related to sea-level rise. The
conventional wisdom is that sea level is rising by a small
amount, but observations show it’s rising about twice as fast as
the models suggested. Could it actually go up by a large amount
in a short period? I don’t think you can rule that out.”
and Baker found that changes in weather patterns may already be
novel thing we did was to do an analysis of just how unusual the
recent weather has been, based on the longest historical
database we have,” McElroy said.
net conclusion is that weather is changing dramatically in
specific regions, and the nature of the change is that we’re
seeing more record high temperatures and many, many fewer
potential effects, McElroy said, are tied to changes in an
atmospheric circulation pattern called the Hadley circulation, in
which warm tropical air rises, resulting in tropical rains.
air moves to higher latitudes, it descends, causing the now-dry air
to heat up. Regions where the hot, dry air returns to the surface
are typically dominated by desert.
The problem, he said, is that evidence shows those arid regions are
observational data suggest that the Hadley circulation has
expanded by several degrees in latitude,” McElroy said.
“That’s a big deal, because if you shift where deserts are by
just a few degrees, you’re talking about moving the southwestern
desert into the grain-producing region of the country, or moving
the Sahara into southern Europe.”
report is the result of the authors’ involvement with Medea, a group
of scientists who support the U.S. government by examining
declassified national security data useful for scientific inquiry.
decades, the group has worked with officials in the United States
and Russia to declassify data on climatic conditions in the Arctic
and thousands of spy satellite images.
images have been used to study ancient settlement patterns in the
Middle East and changes in Arctic ice.
would be reluctant to say that our report is the last word on
short-term climate change,” McElroy said.
“Climate change is a moving target. We’ve done an honest, useful
assessment of the state of play today, but we will need more
information and more hard work to get it right. One of the
recommendations in our report is the need for a serious
investment in measurement and observation. It’s really important
to keep doing that, otherwise we’re going to be flying blind.”
“The bottom line is that our national security depends on our
ability to sustain and augment our scientific and technical
capacity to monitor unfolding events and forewarn of important
changes,” Baker said.
imminent increase in extreme events will affect water
availability, energy use, food distribution, and critical
infrastructure - all elements of both domestic and international
was conducted with funds provided by
the Central Intelligence Agency.
opinions, findings, conclusions, or recommendations expressed in
this material are those of the authors and do not necessarily
reflect the view of the CIA or the U.S. government.