Impacts of Global Climate Change on USAF Operations
Summary
Background and Tasking
The US Air Force has been tasked by congress to address the potential impacts of climate
change on US military operations in the quadrennial defense review (AF/QDR). AF/QDR in turn
has requested assistance from the Naval Postgraduate School (NPS) in both defining and
describing global warming in general, and then identifying likely major impacts of global
warming on US military operations. In July of 2009, NPS delivered a power point presentation
[1] that provided working definitions of climate change related terms, gave a brief description
of the science behind global warming, linked global warming and climate change, and identified
regions particularly sensitive to climate change, and identified four major categories of how
climate change is impacting and will impact USAF operations.
Summary
Studies have been completed recently that discuss the national security implications of climate
change [2 -4]. Additionally, other documents exist that discuss in great detail the future effects
of global warming / climate change on the planet, with the Intergovernmental Panel on Climate
Change (IPCC) 2007 [5 and 6] being the most exhaustive, comprehensive yet even-handed
document available. It is not our intent to summarize references such as these or duplicate
their efforts. Rather, the goal for this document is threefold:
1. It provides a handful of working definitions associated with climate change and
attempts to debunk the myth that the climate change observed particularly since the
1950’s, is due to natural causes and is not due to the generation of greenhouse gasses
by mankind.
2. It identifies a sampling of DoD and Air Force specific challenges that are a result of
climate change.
3. It highlights reputable but underutilized resources, for assessing the impacts of climate
change.
Department of Defense Impacts
Climate Change: Fact or Fiction?
While there are plenty who deny the existence of global warming (the initial forcing mechanism
behind the many facets called climate change), or, more commonly refuse to accept that
climate change is due principally to man-made causes (also known as anthropogenic forcing),
there is little doubt that climate change is real, and its manifestations appear to be accelerating.
Likewise, the science behind the assertion that climate change is due predominantly to manmade causes is valid [7], with anthropogenic forcing being the only plausible explanation for the
observed climate change that withstands scrutiny. Scientists for decades have warned that
continued unabated emission of greenhouse gasses would ultimately lead to a warmer planet.
Climate data collected (especially since the 1950’s) demonstrates that this warning was correct,
and validates the assertion that greenhouse gas emission could indeed impact the planet’s
climate.
For the purposes of this paper we make use of the following definitions:
Global Warming:
A pronounced, measurable, statistically significant increase in the global average surface
temperature of Earth over time.
We find that this warming trend is significant at over a 99.9% confidence level. Figure 1 shows
the change in global averaged surface temperature over time. While there is debate over the
causes of the observed trend (e.g., natural temperature cycles, sunspot activity, increased
urbanization in vicinity of observation stations, human emissions of CO2 and other greenhouse
gasses, etc.), there is no question that the warming trend is real. The term global warming
over-simplifies a complex set of processes, but it is an accurate description of a key element
and initiating factor for a wide range of recent and projected changes in Earth’s climate.
Figure 1. Change in the average surface temperature of the earth over time
Climate Change:
A pronounced, measurable, statistically significant change in Earth’s average conditions
The term climate change describes the combined set of changes due to natural and human
factors. Thus, the term includes global temperature change as well as changes in winds,
evaporation, humidity, cloudiness, precipitation, tropical cyclones, ice coverage, ocean
currents, sea level, glacial melt rates and other climate system variables. These climate
changes: (a) are not spatially uniform but vary with location; and (b) are not temporally uniform
but vary with time. For example, there are some regions of the planet were the net result of
climate change actually is a pronounced cooling!
Earth’s climate has never been fixed or constant. There are numerous natural oscillations and
other variations in the climate system that have led to large and small climate changes
throughout Earth’s existence. The processes that cause climate change are complex and involve
myriad interconnections and feedback systems in Earth’s climate system. This constant change
in, and the complexity of the climate system make the analysis and prediction of climate change
very challenging. This issue is further complicated by the relative lack of quality data (much not
available until the satellite age) when compared to the time scales of climate. Therefore
models depicting climate change, and the predictions made based on these models are subject
to (sometimes substantial) error. This does not mean that climate change is not real, it just
reflects the fantastic difficulty in modeling this uncharted territory.
Greenhouse gasses:
Gasses such as water vapor and CO2 which limit the loss of heat energy (via radiation) of the
earth to space. Greenhouse gasses exist naturally, but the concentration of certain gasses such
as CO2 have increased dramatically with the burning of fossil fuels. This change in atmospheric
greenhouse gas concentrations has only become truly significant since the 1950’s and is due to
two primary causes: the increased industrialization that is leading to increased net greenhouse
gas generation per human, and an explosion in the earth’s population. Currently, both gas
generation per human and population are growing unabated, as is greenhouse gas emission.
Anthropogenic forcing:
Human-induced processes that contribute to global warming and other changes in
Earth’s climate
Anthropogenic forcing includes the enhancement of the greenhouse effect caused by human
emissions of CO2 (see Figure 2) and other greenhouse gasses that then lead to an increase in
Earth’s temperature. The emission of greenhouse gasses into the atmosphere is in large part a
result of the use of carbon-based fuels for transportation, power generation, heating and
cooling, manufacturing, food production, etc. Deforestation also leads to increased emissions
and reduction of natural greenhouse gas removal. These effects clearly have the potential to
lead to increased temperatures. Human emissions of CO2 have led to a large, easily measurable
increase in atmospheric CO2 concentrations. As mentioned previously, these emissions of CO2
are continueing to increase due in large part to continued industrialization and population
growth.
CO2_Concentration _(PPM)
380
360
340
320
300
1950
1960
1970
1980
Year
1990
2000
2010
Figure 2. Change in atmospheric CO2 concentration over time (from NOAA’s Earth System
Research Laboratory)
While keeping in mind that statistical relationships do not prove causality, there is a clear,
strong positive relationship between CO2 concentration and global average surface
temperature, at over a 99.9% confidence level (Figure 3). Moreover, atmospheric CO2 has a
long residence time (hundreds of years). So even if the increase in CO2 emissions were to stop,
it would take many decades for CO2 concentrations, and Earth’s temperature, to return to their
prior levels.
0.6
Temp Anomaly, Deg F
0.4
0.2
0.0
-0.2
300
320
340
CO2_(PPM)
360
380
Figure 3. Change in the average surface temperature of the earth plotted against atmospheric
CO2 concentration. Note the strong positive nature of the relationship.
DoD and Air Force Challenges due to Climate Change
Given that atmospheric greenhouse gasses are increasing, and at a greater than linear rate, and
that greenhouse gasses lead to increased global temperatures, the forcing mechanism for
climate change, we conclude that there will be impacts on the DoD in general and specifically
for the USAF, and we categorize these impacts into four broad categories:
1.
2.
3.
4.
Societal Risks
Facilities / Infrastructure Impacts
Weapons Systems / Sensors / Warfighter Impacts
Operational Tempo / DoD Wide Impacts
It must be understood that the impacts discussed below are not an all encompassing definitive
list of climate change imposed challenges. Rather they are intended to be examples that
demonstrate the breadth and scope of the challenges that climate change is presenting and will
continue to present to the DoD and the USAF. Each of the services will need to re-examine the
fundamental assumptions that were made regarding climate and the environment with respect
to procurement, maintenance, roles, missions, strategies, tactics and procedures, installation
maintenance and viability, budgeting and manpower, or risk discovering after the fact that
capability gaps exist because the environment has changed.
Societal Risks
The stresses on society due to global warming are numerous. Peak summer temperatures are
expected to climb, as is the severity of summer heat waves. But in addition to higher
temperatures, other expected societal stressors would include increased severity and
occurrence of drought, reduced crop yields, rising sea levels and corresponding increased risk
for coastal flooding, increased severity in storms and tropical cyclones, lessened availability of
drinking water, and increased migration caused by all of these stressors [2]. These stressors will
increase regional volatility, adding to the burden on US Forces as they try to foster and
maintain regional stability. Not all stressors will occur evenly across the globe, and the ability
of different nations to cope with these stressors will vary greatly. CNA, 2009 [2] discusses state
stability in light of these stressors in great detail.
Facilities / Infrastructure Impacts
The DoD will face increased threats to its facilities and infrastructure. The DoD and the USAF
have numerous coastal or island bases, and these will face an increased risk of coastal flooding
and damage due to stronger storm surges and raised sea levels. Figure 4 shows Pacific Basin
USAF installations, and it is clear that as sea levels continue to rise, some of these installations
will no longer be viable, at least not without significant investment to make them more resilient
to damage from sea water intrusion. Already anecdotal evidence shows that Kwajalein has
experienced “washover” from seas as rising sea levels take their toll. Increased risk of severe
tropical cyclones also increases the likelihood that DoD infrastructure / facilities will be
damaged. Additionally there are more subtle yet important impacts, as climate change
continues, heating, cooling, and hydrating requirements will all deviate more and more from
their previous long term averages, meaning costs (such as for cooling) will deviate from
“normal”, and systems, once built to handle a specified worst case scenario, may wind up not
being sufficient for the demands imposed by a changing climate. Moreover, as the nation
begins to turn to alternative fuels / energy sources as a coping mechanism to mitigate climate
change, facilities too will have to change to be able to handle, deliver, use or generate the new
fuels.
Figure 4. USAF ases and locations.
Weapons Systems / Sensors / Warfighter Impacts
The impacts of climate change on weapons systems / sensors / and the warfighter are both
numerous and varied. For example, research conducted by NPS indicates that Iraq (and other
parts of the Middle East) are experiencing both reduced winter and spring precipitation, and
increased spring winds, resulting in increased dust storm activity. This increased dust storm
activity, particularly in a region vital to US national security interests, has serious negative
repercussions both on personnel and on equipment. Increased temperatures in general are
hard on machinery, and may render installed cooling systems inadequate. Likewise, fatigue
becomes a greater issue for the soldier as temperatures increase. Even things such as low
observable materials are negatively impacted by the increased humidity, precipitation and
airborne particulates that accompany climate change. Sensors, likewise, are impacted by
climate change as increased temperatures, humidities and atmospheric particulates all impact
performance and maximum sensor ranges. Increased sensor assets may be required to survey
the given area over a given tome because of reduced sensor ranges or resolutions.
Operational Tempo / DoD Wide Impacts
In a climate changing world, US military operations will only increase. There will be greater
demands placed on DoD to respond to climate change based humanitarian crises. Missions to
foster regional stability will become needed even more as tensions rise in regions poorly
equipped to cope with the stresses imposed by climate change. New missions will be
introduced such as patrolling / protecting the arctic and its natural resources as sea ice extent
continues to decline (see Figure 5).
Figure 5. Arctic sea ice coverage now and future [6]. Arctic shipping and resource exploration
and development will result in new missions for the DoD.
Additionally, there will be additional demands on the DoD budget as the US shifts to (initially at
least) more expensive alternative fuels. There will be the burden of external (political or
finacial) pressure on the DoD to reduce the size of its carbon footprint. While efforts such as
efficiency initiatives, or installation of alternative energy productions sites are laudable, they
detract from the primary DoD mission. Finally, climate change may force the early retirement
of platforms or systems incapable of operation in a changing climate or too dependent on
traditional fuels. This will all come at a time where there will be increased demands on the
federal budget. The federal budget, already in record deficit territory will be tapped for nonDoD purposes to deal with climate change. Natural disasters at home, such as severe hurricane
landfalls, or severe drought in the continental south west, driven by climate change, will require
federal dollars for recovery and / or mitigation.
Prediction of Near Present and Future Impacts: The Challenge and
Resources
For Air Force or DoD leadership, References 2 through 6 are a great first step in understanding
the breadth and scope of climate change presently and as it will be in the future. However,
there are many other climate change analysis resources that have remained surprisingly
untapped. While the IPCC, 2007 documents are a great source of information on a variety of
different impacts over varying conditions and time periods, there are concerns. It is difficult to
know how good the analyses are, how accurate the models used are, and whether results are
skewed by the personalities, beliefs, or politics of the scientists involved. Moreover, as models
and simulations are never perfect, and are only as good as the data and assumptions used to
make those models, examining climate change analyses from multiple independent sources
increases the likelihood that leadership is fully apprised of future impacts and what the
magnitudes, variances, and confidences are for those projected impacts. While it is frustrating
that climate change predictions and the models they are based on suffer from error, better
quality, higher resolution data sets, better computational tools, and better understanding of
the complexities of how the earth’s climate works is improving the accuracy and usefulness of
forecasts.
However, at the same time the US government has significant resources at its disposal for
quantifying, understanding and predicting the impacts of climate change. The National
Oceanic and Atmospheric Administration (NOAA), found at http://www.noaa.gov/ has world
class and state of the art data sets, scientists, computational capabilities, resources, models and
prediction tools that would allow for prediction and analysis of climate change concerns, either
in broad generalities or on a specific case by case basis. Under the auspices of NOAA are also
the Climate Prediction Center (CPC), found at http://www.cpc.noaa.gov/, the Climate
Diagnostic Center (CDC), found at: http://www.esrl.noaa.gov/psd/, and the National Centers for
Environmental Prediction (NCEP), found at http://www.ncep.noaa.gov/. Besides having the
necessary expertise and tools needed to conduct analyses for the DoD, these organizations,
being agencies of the federal government would be better suited than any others to do
sensitive research for the DoD.
Other organizations that are fully capable of cutting edge research on behalf of the DoD to
address specific climate change impacts would include the National Hurricane Center (NHC)
found at: http://www.nhc.noaa.gov/, and with its meteorology department, expert faculty,
computational capabilities, cross departmental opportunities and pool of graduate students,
the Naval Postgraduate School is also a research tool capable of assisting the USAF in assessing
climate change risks. In fact NPS is already engaged in significant research and prediction
efforts designed to take the effects of climate change into account.
Recommendations
While this document was intended to provide a high level look at climate change and its
present and future impacts on the USAF, the next steps need to be very specific.
1. Leadership needs to understand that climate change is legitimate, and will be
substantial. Greenhouse gas removal from the atmosphere is a long term process
(decades to centuries) and the planet’s consumption of fossil fuels continues unabated.
Even with the best of intentions willpower, and government leadership, the planet will
being dealing with significant impacts due to global warming for generations. Climate
change will become far more significant before it gets better.
2. Climate change needs to be addressed proactively instead of reactively. For example,
investigate now the viability of coastal or island bases. It is far better to relocate or
harden in a controlled fashion than have a necessary base be eliminated in 20 years
because tropical cyclones and sea level rise finally caught up to it. Likewise, it is
essential to ensure that requirements documents, when specifying environmental
conditions, address what the environment likely will be when the system is in service, as
opposed to what the climate was in the past.
3. Take advantage of the many resources of the federal government. NOAA and its various
sub organizations are scarcely even mentioned in References 2-4, yet are capable of
doing perhaps even better work than IPCC 2007, and certainly can tailor products to
specific DoD and USAF needs. Likewise NPS and the US National Laboratories can
conduct excellent research for individual DoD or service concerns, and should be
utilized.
References
[1.] Naval Postgraduate School, Impacts of Global Climate Change on USAF Operations:
Project Update Report, T. Murphree and D. Meyer, 1 July 2009.
[2.] CNA, National Security and the Threat of Climate Change, Washington D.C.,
November 2007.
[3.] CNA, Global Climate Chang and State Security, Washington D.C., November 2007.
[4.] Dr. Thomas Fingar, National Intelligence Assessment on the National Security
Implications of Global Climate Change to 2030, Testimony before the House Permanent
Select Committee on Energy Independence and Global Warming, 25 June 2008.
[5.] IPCC, Climate Change 2007: The Physical Science Basis. Contribution of Working
Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate
Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor
and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New
York, NY, USA, 2007
[6.] IPCC, Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of
Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on
Climate Change [M.L. Parry,O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E.
Hanson, Eds.]. Cambridge University Press, Cambridge, United Kingdom, 2007
[7.] Introduction to Heat Transfer, Second Ed., F. Incropera and D. DeWitt, John Wiley and
Sons, New York, Chichester, Brisbane, Toronto, Singapore, 1990
Additional information can be obtained from:
National Intelligence Assessment 2008-01 National Security Implications of Global Climate
Change to 2030 (U), 2008