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 man-made 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.

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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.

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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. Societal Risks2. Facilities / Infrastructure Impacts3. Weapons Systems / Sensors / Warfighter Impacts4. 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 non-DoD 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