Climate Change and National Security: Balancing the Costs and Benefits

June 10, 2020 • Publications
By Mark G. Stewart

If climate projections are correct, a changing climate has the potential to cause sea levels to rise, floods, more intense storms and hurricanes, droughts, and other climate extremes. Such climate change would affect every nation, and populations in developing countries would be hit hardest. In the worst case, it would lead to energy and food scarcity, increase the spread of disease, cause mass migration of “climate refugees,” and weaken fragile governments.

That is all alarming stuff. However, those effects are often predicated on worst‐​case (and unlikely) carbon dioxide (CO2) emission scenarios and climate projections to 2100 and beyond, and they ignore technological innovations and adaptive behaviors.

This chapter focuses on climate change as a potential national security threat to the United States.1 Taking the projections as reality, Admiral Samuel J. Locklear III, commander of U.S. Pacific Command, contends that a significant upheaval related to the warming planet would “cripple the security environment” and is “probably more likely than the other scenarios we all often talk about.”2 Others claim that “climate change is becoming one of America’s most critical national security issues of the 21st century”3 or that “climate change represents a serious threat to the security and prosperity of the United States.”4

An open letter signed by 38 U.S. national security experts in 2013 states that climate change “presents a serious threat to American national security interests,”5 and a 2007 report by a military advisory board concludes that “climate change is a threat multiplier for instability in some of the most volatile regions of the world, and it presents significant national security challenges for the United States.”6

Not surprisingly, the 2010 Quadrennial Defense Review by the U.S. Department of Defense concludes that “climate change and energy will play significant roles in the future security environment” and highlights several specific climate threats to national security:

  • Opening of new territorial waters in the Arctic;
  • Regional instability caused by food and energy insecurity, and associated increases in refugees;
  • Vulnerability of military installations to hurricanes, storms, floods, sea‐​level rise, and other climate change–induced hazards; and
  • Increased use of military resources for humanitarian and largescale natural disaster missions.7

This chapter assesses such concerns. It estimates that those threats, should they materialize, could conceivably cost the U.S. government up to $20 billion per year. However, that cost would increase federal government outlays by no more than 0.5 percent, requiring an adjustment that is not very significant.8 For example, climate and extreme weather threats to military installations within the United States can be readily handled by adaptation strategies, such as seawalls, improved infrastructure resilience, and—as a worst case—relocation of bases to less vulnerable locations. The opening of the Arctic to shipping would require new icebreakers to patrol sea‐​lanes and investment in new infrastructure to support Arctic operations. And future humanitarian missions might be better handled by civilian agencies, such as the United Nations, if properly resourced.

In addition, global warming has benefits that should be considered. For example, the anticipated opening of the Northwest Passage and other “trans‐​Arctic” waterways by 2030 would reduce shipping times between Europe and Asia by 50 percent while opening up the area to the exploitation of more than $1 trillion of hydrocarbon and mineral resources.9

The United States has met many threats to its security in the past century, including two world wars and engagements in many parts of the globe. If the direst predictions are proved correct, climate change will adversely affect many facets of life in the United States—“business as usual” may not be an option, and climate change will require a whole‐​of‐​government response that will surely present challenges to the United States and its allies. However, to call it a “security threat” is excessive. And to keep matters in perspective, few if any analysts believe that climate change constitutes an existential threat to the United States. The very existence of some small island nations could be threatened by rising sea levels, but the United States is a large country with significant resources and adaptive capacity. It has proved to be a highly resilient nation, and it is reasonable to expect that admirable national trait to continue.

Climate Change Impacts

The 2013 Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) concluded: “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased.”10 Less certain is the impact that rising temperatures will have on sea levels, rainfall, wind patterns, and other potentially damaging phenomena. An evaluation of the accuracy of climate‐​impact modeling is not the topic of this chapter; others can shed light on those important issues.11 Instead, the chapter will explore how climate change will affect U.S. national security assuming that worst‐​case scenarios actually take place.


Considerable literature exists on the impact of climate change; most of it dwells on the negatives, which all too often make up a litany of future catastrophes. We start with the IPCC’s Fourth Assessment Report released in 2007, a weighty tome that runs to nearly 3,000 pages, which is not surprising given that the three‐​volume report had more than 500 lead authors and 2,000 expert reviewers. For the sake of brevity, the following main anticipated climate changes by 2100 are relevant to the issue of U.S. national security:12

  • A temperature increase from 1990 levels of anywhere from 2 to 11 degrees Fahrenheit;
  • A sea‐​level rise of 8 to 24 inches or more;
  • More intense tropical cyclones and other severe wind events;
  • Increases in precipitation in high latitudes with decreases in Central America, southern Africa, and southern Europe;
  • Enhanced monsoon precipitation in much of Asia; and
  • A reduction in Arctic sea ice of 22 to 33 percent.

The report then suggests with high or very high confidence that those changes to climate will cause the following:

  • A decline in water volumes stored in glaciers and snow cover, thus reducing summer and autumn flows in regions where more than one‐​sixth of the world’s population currently lives;
  • An increase in drought‐​affected areas and an increase in the frequency and intensity of extreme precipitation events, thereby augmenting flood risk that will have implications for sustainable development;
  • An increase in the number of people living in severely stressed river basins from 1.4–1.6 billion in 1995 to 4.3–6.9 billion in 2050 in the A2 (high) emissions scenario;13
  • A marginal increase in the number of people at risk of hunger;
  • Significant consequences on food and forestry production, and food insecurity from changes in the frequency and severity of extreme climate events, together with increases in the risks of fire, pests, and disease outbreak;
  • An increase in global food production as the global average temperature rises about 5 degrees Fahrenheit, with decreases likely above that level;
  • A likely increase of risks to coasts, affecting more than 100 million people yearly by the 2080s if there is no adaptation, an effect that will be exacerbated by increasing human‐​induced pressures on coastal areas, particularly where the stresses on natural low‐​lying coastal systems coincide with low human adaptive capacity or high exposure as in deltas, low‐​lying coastal urban areas, and lowlying atolls;
  • Rises in social‐​equity concerns in many areas, thus increasing pressures on government infrastructures and institutional capacities;
  • Additional risks from malaria for between 220 million and 400 million people, although projections are mixed; and
  • Significant increases in the number of people at risk of death from heat, depending on the place, the aging population, and the adaptation measures in place.

Speed of Change

It is important to note that those effects will not be sudden but will be gradual in their appearance. The observed increase in weather‐​related losses in the United States and elsewhere is more a function of increased exposure with more people moving to vulnerable coastal locations than of climate‐​change increases in wind speed or flood levels.14 For instance, although hurricane wind speeds are predicted to increase at worst by 10 percent in 50 years because of climate change, that increase represents a minuscule 0.2 percent per year.15 Contrast that to the population growth rate in Florida and other southern states, which is double that of the United States at large and is running above 2 percent per year.

That fact suggests that there will be ample time to adapt to a changing climate, which can be readily handled by adaptation strategies to help “climate‐​proof” vulnerable populations and infrastructure.

Economic Costs

The 2006 review by economist Nicholas Stern is considered by many to be the most comprehensive economic assessment of climate change to date—it is also highly pessimistic in its assumptions.16 The review predicts that if no action is taken against climate change, the costs of “inaction” would be equivalent to losing 5 to 20 percent of global gross domestic product (GDP) each year “now and forever,”17 and by 2200, the 95th percentile (upper bound) of losses per GDP per capita could reach 35.2 percent.18 Those are staggering losses, equivalent to worldwide losses of up to $25 trillion each year.

Those numbers, however, do not take into account wealth creation, human capital, and new improved technologies. Indur Goklany, science and technology policy analyst for the U.S. Department of the Interior, states that those other factors “often reduce the extent of the human health and environmental ‘bads’ associated with climate change more than temperature increases exacerbate them.”19 Goklany gives us a choice between two futures: (a) a warmest but richest A1FI (higher carbon) emission scenario20 since higher economic growth is usually associated with high use of fossil fuels, which are cheaper than most forms of renewable energies, and (b) the poorer A2 scenario,21 which reduces CO2 emissions by using more costly—albeit cleaner and renewable—energy sources. According to Goklany, hunger, coastal flooding, and malaria currently claim 4.4 million lives a year. Goklany then shows that in the absence of climate change, a richer world will reduce those mortalities by 2.3 million by 2085.22 Climate change will increase hunger, coastal flooding, and malaria mortalities by 237,000 by 2085—giving a net decrease of 2 million mortalities for the first emission scenario.23 Conversely, the second scenario would increase mortalities by nearly 2 million by 2085.

Clearly then, if people are wealthier in the future, their well‐​being will be higher, and “the argument that we should shift resources from dealing with the real and urgent problems confronting present generations to solving potential problems of tomorrow’s wealthier and better positioned generations is unpersuasive at best and verging on immoral at worst.”24 The litany of catastrophes that many in the climate‐​change community dwell on may prove to be unfounded if people are wealthier in the future.


In addition, climate change has clear benefits, and they should be taken into consideration. For example, reductions in cold‐​related deaths from climate change are projected to be greater than increases in heat‐​related deaths in the United Kingdom.25 Of course, the anticipated opening of trans‐​Arctic waterways will reduce shipping times between Europe and Asia, and melting sea ice may also allow for more rapid exploitation of scarce hydrocarbon and mineral resources in the Arctic.

Evaluating the Threats

With that information as background, this chapter will now assess the climate‐​change threats to U.S. national security as identified in the Quadrennial Defense Review assessment, and assumes that the changes predicted by the IPCC’s 2007 report take place.

Melting Sea Ice in the Arctic

The issue that frequently rises to the top of any discussion about climate change and U.S. national security is the melting of sea ice in the Arctic.26 For several decades now, the average surface air temperatures in the Arctic have increased at double the global average, which has caused noticeable reductions in summer sea ice.27 Thus, when a commercial ship, the super ice‐​class vessel MV Camilla Desgagnés, traveled through the Northwest Passage in 2008, the Canadian Coast Guard called it a “major first” because the area “has historically been impassable with thick ice.” Remarkably, the crew “didn’t see one cube of ice.”28 Such crossings are increasing in frequency, with 46 ships sailing the entire length of the Northern Sea Route from Europe to Asia in 2012.29

Christine Parthemore from the Center for a New American Security lists melting sea ice as “today’s biggest challenge.”30 Projections suggest that by 2050, the Northern Sea Route will have 125 days per year with less than 75 percent sea ice cover, which represents favorable conditions for navigation by ice‐​strengthened cargo ships,31 and Figure 8.1 shows how reduced summer sea ice by the middle of the century will most likely open up the Northwest Passage (through the Canadian archipelago) and Northern Sea Route (north of Russia) to shipping and to resource exploitation.

Figure 8.1: Minimum Extent of Sea Ice for Arctic Regions

Minimum Extent of Sea Ice for Arctic Regions

Source: Parry et al., Climate Change 2007: Impacts, Adaptation and Vulnerability, Con‐ tribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge: Cambridge University Press, 2008), vol. 2, Figure TS 16.

The thinning and retreat of Arctic sea ice present both threats to and opportunities for the United States.

The opening of shipping lanes in the Arctic, at least for parts of the year, would reduce the transit distance between Europe and Northeast Asia (China, Japan, South Korea, and Taiwan) by 4,000 nautical miles and would reduce shipping times by two weeks.32 That reduction will translate into significant savings, particularly to European and Asian nations—up to $80 billion annually for China, Japan, and South Korea.33 In addition, the U.S. Geological Survey estimated that the Arctic region holds about 30 percent of the world’s undiscovered gas and 13 percent of the world’s undiscovered oil—and the undiscovered gas is mainly concentrated in Russia.34 Opening that area to exploitation may produce more than $1 trillion of hydrocarbon and mineral resources.35

That assessment has led the five Arctic nations—Canada, Denmark, Norway, Russia, and the United States—to cement or expand their territorial claims to the Arctic. Canada claims sovereignty over much of the Northwest Passage, a claim disputed by the United States. Russia planted a titanium flag on the seabed of the North Pole in 2007. Canada, Denmark, and Russia have each filed claims to oil and mineral resources of the seabed in the Arctic Ocean under the United Nations Convention on the Law of the Sea (which has not been ratified by the United States).36 The White House and many analysts strongly recommend that the United States ratify that convention to give the United States a formal framework to help settle unresolved territorial sea and exclusive economic zone disputes.37

There are opportunities to be exploited in the Arctic, as well as risks to U.S. national security caused by the opening of a new frontier (Arctic) to potential adversaries. However, the United States, the “reluctant Arctic power,” has been slow off the mark.38 The U.S. Navy ceased operating icebreakers in 1966, and the U.S. Coast Guard (USCG) has shrunk to only two icebreakers39 (USCGC Polar Star and USCGC Healy), one of which had to be brought out of retirement in 2012. Those icebreakers are deployed in both polar regions. The primary mission of the USCG icebreaking “fleet” is to support the following missions:40

  • Conducting and supporting scientific research in the Arctic and Antarctic;
  • Defending U.S. sovereignty in the Arctic by helping to maintain a
  • U.S. presence in U.S. territorial waters in the region;
  • Defending other U.S. interests in polar regions, including economic interests in waters that are within the U.S. exclusive economic zone north of Alaska;
  • Monitoring sea traffic in the Arctic, including ships bound for the United States; and
  • Conducting other typical Coast Guard missions (such as search and rescue, law enforcement, and protection of marine resources) in Arctic waters, including U.S. territorial waters north of Alaska.

In July 2011, the Coast Guard provided Congress a study on the USCG’s missions and capabilities for operations in high‐​latitude (i.e., polar) areas and recommended that the USCG needs, at a minimum, four heavy and two medium icebreakers—at a cost of $5 billion.41 That cost is less than 1 percent of U.S. defense outlays, and it could be funded by, for example, reducing the number of attack‐​class submarines from 46 to 44.42 Congress to date has approved funding for only one new icebreaker. Contrast that to the ice‐​breaking capabilities of Russia, which has four icebreakers with 13 more either under construction or planned. Canada has five icebreakers, and Denmark has four.43

U.S. military navigation and communication systems have been optimized for nonpolar regions, and GPS satellites have slightly degraded performance for high latitudes with errors of up to 250 feet.44 A low‐​cost solution seems to be augmenting (correcting) the GPS signal by transmitting corrections from either land‐​based beacons or high‐​latitude satellites. Communication systems would also need upgrading to deal with ionospheric disturbances and increased tempo of Arctic operations.45 The cost of new satellites dedicated for U.S. Arctic communications ranges from $320 million to $1 billion.46 Clearly, the total cost for enhanced Arctic communications and navigation for all U.S. military services is not excessive; it is something on the order of $500 million over a decade. The U.S. Air Force has aircraft with a wide range of capabilities that can operate in Arctic conditions with two air bases in Alaska and one in Greenland. The U.S. Army has active combat and infantry brigades in two locations in Alaska, and it also maintains a significant aviation presence there.47 Distances in the Arctic are immense, and existing support infrastructure is sparse. However, additional naval, air, and ground forces can likely be deployed without significant additions to existing shore‐​based infrastructure.48 Moreover, U.S. forces can use land‐​based infrastructure in Canada, Denmark, and Norway as part of the North Atlantic Treaty Organization. The United States currently spends about $350 million per year on military construction in Alaska.49 At worst, upgrading military bases in Alaska by as much as 50 percent would cost no more than $200 million per year.

The U.S. Navy has recognized that its “forces lack experience and procedures for the challenges of these northern environments,”50 but “unclassified national intelligence assessments suggest a low likelihood of significant conflict in the Arctic region in the foreseeable future,”51 and “relationships among the Arctic nations will remain generally stable and cooperative.”52 That evaluation probably explains the apparent lack of urgency in addressing shortcomings in Arctic defense planning.

Finally, the opening of the Arctic to shipping will allow more rapid naval deployments between the Atlantic and Pacific Oceans. That result will reduce reliance on Panama and its canal, a region not known for political stability, and will greatly assist operational planning for optimal placement of U.S. naval forces. The national security benefits of melting sea ice seem to justify the cost of taking advantage of them.

Regional Instability

It is argued that an increased likelihood of droughts, floods, famine, disease, loss of habitable land, damage to housing and infrastructure, and other large‐​scale natural and humanitarian disasters will place additional stress on communities and governments. If climate projections are accurate, that increased stress could be a “threat multiplier,” leading to “widespread political instability” and “failed states,” while fostering “the conditions for internal conflicts, extremism, and movement toward authoritarianism and radical ideologies.” It is maintained that the logical outcomes of those dire scenarios mean “the U.S. may be drawn more frequently into these situations … to help provide stability before conditions worsen and are exploited by extremists” and “the U.S. and Europe may experience mounting pressure to accept large numbers of immigrant and refugee populations.”53

Retired Admiral T. Joseph Lopez gloomily predicts that “climate change will provide the conditions that will extend the war on terror.”54 That prediction, of course, assumes business as usual with no efforts to mitigate CO2 emissions, to implement climate adaptation strategies, to develop new technologies, or to achieve improvements in wealth creation and human capital. It also assumes that terrorism thrives in “failed states.” Although that conclusion is true in some cases, a 2008 Congressional Research Service report finds the opposite also holds true: “Terrorists have been known to exploit safe havens in non‐​weak as well as weak states. The Political Instability Task Force, a research group commissioned by the Central Intelligence Agency, found in a 2003 report that terrorists operate in both ‘caves’ (i.e., failed states, where militant groups can exist with impunity) and ‘condos’ (i.e., states that have the infrastructure to support the international flow of illicit people, funds, and information).”55

Moreover, after the costly enterprises in Iraq and Afghanistan, the United States and its allies will likely resist the temptation to get drawn into peacekeeping and stabilization missions to rescue “failed states.” As former secretaries of state Henry A. Kissinger and James A. Baker III attested in 2011: “We cannot be the world’s policeman. We cannot use military force to meet every humanitarian challenge that may arise.”56 Moreover, other foreign policy levers—such as financial aid for transformational development, civilian stabilization, and reconstruction assistance; the fragile states strategy of the U.S. Agency for International Development; and military, police, and counterterrorism assistance57—will typically produce better outcomes than direct military intervention.

There is additional concern about refugees. According to the UN High Commissioner for Refugees, in 2011 there were 15.2 million refugees, 26.4 million internally displaced persons, and 895,000 applications for asylum. Conflicts in Afghanistan, Iraq, and Syria have added to those figures. Sea‐​level rise in river deltas has the potential to displace tens of millions of inhabitants and might threaten the very existence of small island states. Maxine Burkett from the East–West Center in Honolulu estimates a total of 200 million to 250 million climate migrants by 2050, although some of those projections are based on “heroic extrapolations.”58 Moreover, Jon Barnett and Michael Webber from the University of Melbourne suggest “that social processes linked to poverty and marginality as well as the treatment of migrants may be more important determinants of the amount and consequences of migration than environmental change.”59

However, if intracountry and intercountry migration accelerates because of climate change, it would most likely happen in a gradual manner and not in any sudden exodus of refugees more commonly associated with war zones. The populations of small island states are by definition small—fewer than 3 million people reside in Pacific Islands, for example. More ethnic Pacific Islanders live abroad than reside in their home countries; therefore, “the greatest concentrations of Pacific Islanders” are “in cities such as Auckland, Sydney, Honolulu, and Los Angeles.”60 If all Pacific Islanders were to become “climate refugees” because of rising sea levels over the next 30 to 50 years, and if they were all to be resettled in the United States, Australia, and New Zealand, those countries would need to lift their existing immigration levels by only 5 to 8 percent.61

Migration, whether voluntary or forced, is a perennial feature of life. The International Organization for Migration estimates that the total number of migrants is about 1 billion worldwide today.62 Australia, Canada, and the United States accepted nearly 70 million migrants in the 20th century, and today they welcome nearly 1.5 million new migrants each year.63 Europe accepted 1.7 million migrants in 2011. Immigration to the 34 member countries of the Organisation for Economic Co‐​operation and Development (OECD) totaled 5.3 million in 2011.64 Although climate change may provide a tipping point for mass migration, it is unlikely to occur. Movement of people across borders happens regularly on a large scale. Assuming Burkett’s upper figure of 250 million climate migrants over the next 40 to 50 years, and further assuming that they were all to be resettled in just the OECD member countries, then 5 million additional migrants per year could be accommodated by Australia, Canada, Europe, the United States, and other OECD member countries by doubling their existing migrant quotas. That might not be politically palatable to some, but it is not an insurmountable problem.

Moreover, issues of food and energy security, as well as mass migration, can be ameliorated by funding climate adaptation measures in the developing world. Adaptation measures to reduce the vulnerability of infrastructure, coastal zones, agriculture, forestry, fisheries, and human health to climate‐​change hazards would include (a) flood‐​control dikes and levees, (b) dams, (c) cyclone shelters, (d) storm‐​and‐​flood‐​resistant housing, (e) improved communications infrastructure, (f) resettlement of populations to lower‐​risk zones, and (g) improved health care.

In 2010, the World Bank estimated the cost to the developing world of adapting to a world that is warmer by approximately four degrees Fahrenheit by 2050 at about $75 billion per year.65 That figure represents less than 0.2 percent of world GDP and 55 percent of official development assistance from OECD countries.66 U.S. foreign aid was approximately $30 billion in 2011, or 23 percent of aid provided by OECD member countries. If the 55 percent increase in foreign aid is shared equally by all developed nations, the U.S. foreign aid contribution would need to increase by roughly $16.5 billion per year, and aid from the rest of the developed world would increase by $58.5 billion per year. Increasing foreign aid may be an overly optimistic solution given the “sorry track record” of foreign aid where governance is poor,67 but investing in targeted adaptation measures may have a better chance of success.

Mitigating CO2 emissions and investing in research and development (R&D) of new technologies for emission reduction and carbon sequestration are another option to ameliorate the effects of climate change. One study suggests that a global investment of $18 billion per year in “R&D and mitigation” could halve “business as usual” CO2 emissions by 2100, reducing the impact of climate change by at least 60 percent.68 If that is true and if the burden of that investment were shared by OECD member countries in proportion to their GDP, the U.S. contribution would be around $5 billion per year, equivalent to a tax of only $1 per ton of CO2.69

Modest and sustained investments in R&D, CO2 mitigation, and adaptation will lessen the worst impacts of climate change and would therefore reduce the posited likelihood of regional instability. Under the worst assumption, an increase in foreign aid of $16.5 billion per year (assuming it is used properly) would offset many predicted climate impacts, and thus it would mitigate food and energy insecurities, as well as those associated with increases in refugees.

Vulnerability of Military Installations

More than 200 military bases are in the United States, and the military maintains and operates hundreds of other facilities abroad.70 Many of them will be vulnerable to climate change. One hurricane caused so much damage to Homestead Air Force Base in Florida that it never reopened, and another closed Naval Air Station Pensacola for a whole year.71 Any need to climate‐​proof key military installations, particularly those in more vulnerable coastal locations, can be readily handled by adaptation strategies, such as seawalls, improved infrastructure resilience, and—as a worst case—relocation of bases to less vulnerable locations. Moreover, the time frame for climate change to have an effect would be long—50 to 100 years—and the relocation of military installations is already a constant feature of U.S. defense planning as postures, technology, and budgets change.72

The cost to climate‐​proof infrastructure is surprisingly low in many cases. Designing new buildings to be 50–80 percent less vulnerable to hurricanes costs only an additional 1–3 percent of the building cost.73 The World Bank arrives at a similar value: “The cost of adapting to climate change, given the baseline level of infrastructure provision, is no more than 1–2 percent of the total cost of providing that infrastructure.”74 Retrofitting existing buildings is more expensive, on the order of 15–50 percent of the building cost.75 Over the next 50 to 100 years, most existing infrastructures will reach the end of their service life and will need to be replaced as a matter of course. Hence, climate proofing will tend to occur more for new infrastructure. That scenario, assuming a high 10 percent cost impost to improve resilience to future climates, would add about $1 billion annually to the current military construction budget of approximately $12 billion.76

There is also much scope for relocation of military assets and personnel between bases in the nearand long‐​term time horizons. Earthquakes and tsunamis strike without warning, often with devastating effect. Fortunately, hurricanes, storms, floods, and sea‐​level rise do not occur without warning, which significantly reduces loss of life and economic losses. A warning of a day or two will allow aircraft, vehicles, ships, and personnel to be deployed to safer locations. There is no doubt that such deployment will affect operational efficiencies, but those types of natural disasters will be localized geographically, and any loss of operational capability could be made up by other regions taking up the slack.

Moreover, predicting the needs of the U.S. military for the next century is as speculative as predicting 20th‐​century U.S. military bases and deployments in 1914. Two world wars, the Korean War, the Vietnam War, a Cold War, and the “war on terror”—not to mention technological advancements—have all dramatically altered the deployment and composition of the U.S. military. The enormous growth of the military use of drones and unmanned aircraft will change the nature of U.S. Air Force operations.77 Air force bases in the future will look very different from the ones today.

The Department of Defense is also tackling the issue of energy efficiency by increasing its use of renewable fuels and reducing energy demand. As the 2010 Quadrennial Defense Review puts it rather bluntly, “Energy efficiency can serve as a force multiplier, because it increases the range and endurance of forces in the field and can reduce the number of combat forces diverted to protect energy supply lines, which are vulnerable to both asymmetric and conventional attacks and disruptions.”78 The U.S. military is already using biofuels, solar and wind energy, and hybrid and electric vehicles to cut fossil fuel usage. If “energy alarmists” are to be believed,79 that practice will help reduce dependence on foreign fuels and will make the United States less vulnerable to hostile regimes. A feature of the military is its ability to quickly adapt to changing circumstances and technological advances. Unlike its political masters, the time horizon for military planning extends well beyond the next election—often by several decades. The military is much more strategic in its decisionmaking; it constantly deals with threat uncertainties, is quick to try new technologies, and is more multidisciplinary than many other branches of the U.S. government. For instance, the military advisory board for the CNA Corporation’s 2007 report “National Security and the Threat of Climate Change” included admirals and generals with degrees in nuclear, civil, and mechanical engineering; international relations; management; history; political science; and economics. If climate hazards do pose a challenge to U.S. military installations or operations, the U.S. military is best placed to decide when and how to react or adapt.

And given an annual budget of more than half a trillion dollars, it has a considerable pool of resources to shift around as priorities change.

Diversion of Military Resources to Humanitarian Missions

The military is often the only government entity with the ability to respond first to natural and humanitarian disasters. It has a ready workforce and equipment under a centralized command, and its logistical prowess can help stabilize shelter, food, communications, and other lifelines of support to victims.

The U.S. Navy has capabilities that make it likely to be the first on the scene in a substantive manner. Hospital ships, U.S. Marine expeditionary units, maritime prepositioning ships, naval mobile construction battalions, and the U.S. Coast Guard all have important natural disaster and humanitarian relief capabilities, including their ability to provide command‐​and‐​control headquarters until shore‐​based forces arrive.80 The aircraft carrier USS Carl Vinson operated as a sea base for helicopters that were moving personnel and supplies into the earthquake disaster area in Haiti in 2010. Added to that were two amphibiousready groups, U.S. Marine expeditionary units, and the hospital ship USNS Comfort.81 More than 70,000 soldiers, including 22,000 active‐​duty troops and 50,000 members of the National Guard, were mobilized in the aftermath of Hurricane Katrina.82 In the weeks following the 2011 tsunami in Japan, the U.S. military sent 20,000 troops, 140 aircraft, and at least 20 ships in support of Operation Tomodachi, but those deployments lasted less than one month.83 Such operations clearly have an effect on military readiness, and as General Paul J. Kern (retired, U.S. Army) from U.S. Southern Command notes, “A major weather event becomes a distraction from your ability to focus on and execute your military mission.”84

The U.S. Navy’s hospital ships are one of the best examples of navy “soft power,” and their secondary mission is “to provide mobile surgical hospital service and acute medical care in disaster or humanitarian relief.”85 They have played significant roles in humanitarian missions in Haiti and the Pacific. The U.S. Navy’s two current hospital ships, the USNS Mercy and USNS Comfort, each contain 12 fully equipped operating rooms, a 1,000-bed hospital facility, digital radiological services, a medical laboratory, a pharmacy, an optometry lab, an intensive care ward, dental services, a CT scanner, and two oxygen‐​producing plants. Each ship is equipped with a helicopter deck capable of landing large military helicopters. Because of their unique capabilities, a 2011 National Research Council report concludes, “The Navy needs to maintain this capability beyond the life of its current two‐​ship hospital fleet.”86 The cost of two new hospital ships is ap proximately $2 billion.87

Natural disasters and humanitarian missions both at home and abroad may hinder the rapid deployment of forces in times of conflict or war. However, the probability of a natural disaster is low, as is a military threat to U.S. national security, and the chances of both occurring simultaneously and in the same region are extremely remote. Although disasters in Haiti and Japan each tied up an aircraft carrier and its battle group for a week or so, the United States had several other carrier strike groups to call on if needed, as well as more than 500,000 soldiers and more than 5,000 aircraft —in other words, the United States was hardly vulnerable to attack during that period. The United States also has an extensive network of military alliances that reach across the globe—and those allies may be called on to assist with natural disaster and humanitarian missions, or to react to military threats against the United States. Many would argue that using the U.S. military to assist with humanitarian disasters has much merit, at least in peacetime. It can foster immense goodwill from the recipient nation and can even open the door to fragile diplomatic relations. It also generally leads to good public relations for the military, and the public is pleased to see the military “doing something.” However, given the increasing reluctance to send soldiers to hostile areas as discussed earlier, many humanitarian missions may in the future be better handled by civilian agencies such as the United Nations, Médecins Sans Frontières (Doctors Without Borders) or other nongovernmental organizations (NGOs). They would need additional resources to do so, however. The UN’s regular budget is on the order of $5 billion, of which the U.S. contribution is assessed as 22 percent, or roughly $1 billion. Added to that is nearly $2 billion for the UN peacekeeping budget, plus additional billions to other organizations in the UN system each year.88 With an annual budget of approximately $1.4 billion, Médecins Sans Frontières has 32,000 field staff members who are in 71 countries, who react mainly to conflict and refugee response, and who treat up to 8 million people each year.89 If the United States and other countries were to double the budgets of the United Nations and Médecins Sans Frontières, then—assuming the increased funds were used effectively—some of the pressures faced by the U.S. military when dealing with natural and humanitarian disasters would be alleviated. A modest U.S. investment of $1 billion or so each year is all that would be needed.

Balancing Costs and Benefits

Table 8.1 tallies the yearly costs associated with ameliorating climate change threats to U.S. national security that might arise and that have been identified in the Defense Department’s Quadrennial Defense Review. The total cost of doing everything—nearly $20 billion—would increase federal government outlays by a very modest 0.5 percent.90 And that assumes, of course, the worst‐​case scenario for climate change. Costs will be substantially lower if the dire predictions of climate change prove to be overblown. The big ticket item is $16.5 billion to provide adaptive strategies to countries in the developing world on the assumption that they will be unable to fund such adaptation on their own. That assumption ignores the evidence from Indur Goklany and others that a wealthier society is better able to cope with climate change, and efforts should be directed to reducing present‐​day vulnerabilities to climate hazards. Clearly, much of the $16.5 billion will not be needed if developing countries increase their wealth, because they will be better able to cope with a changing climate on their own. Any regional instability resulting from climate change will thus be less of a problem than many predict.

The benefits of climate change are harder to tally. As noted, the opening of the Arctic to shipping will mostly benefit trade between Europe and Northeast Asia, and any negative economic impact on the United States will be minimal. Melting sea ice could open additional offshore oil and gas deposits, thereby helping secure America’s energy future, although the environmental effects of such activities may raise additional challenges. On the downside, permafrost thaw could undermine existing roads, buildings, and infrastructure, and when combined with more severe storms and wave actions, offshore drilling may be uneconomic in those circumstances. Any benefits of more accessible resources may be negated by increased damage to Arctic infrastructure.

This chapter has assumed worst‐​case scenarios that dramatically inflate the impact of climate change. Under those scenarios, climate change would appear to pose more negatives than positives for U.S. national security. However, even under the worst‐​case scenarios, climate‐​change threats to U.S. national security are modest and manageable, requiring annual additional costs of no more than $20 billion. Americans may have many reasons to feel insecure, but climate change is not one of them.

About the Author

Mark G. Stewart is Professor of Civil Engineering and Director of the Centre for Infrastructure Performance and Reliability at The University of Newcastle in Australia.


1 Concerns about climate change and national security are not limited to the United States. A 2013 report “Heavy Weather: Climate and the Australian Defence Force” by the Australian Strategic Policy Institute concluded that “the ADF [Australian Defence Force] will always need to have hard‐​edged war‐​fighting capabilities, but it will also have to recognise the increasing requirement for capacity building,” and it’s “about the ADF being well placed to deal with the potential disruptive forces of climate change.” British Rear Admiral Neil Morisetti is quoted by the Guardian (July 1, 2013) as saying, “Climate change posed as grave a threat to the UK’s security and economic resilience as terrorism and cyber attacks” and was “one of the greatest risks we face in the 21st century” because “by virtue of our interdependencies around the world, it will affect all of us.”

2 Bryan Bender, “Chief of US Pacific Forces Calls Climate Biggest Worry,” Boston Globe, March 9, 2013.

3 Stephen Cheney, “Climate Change Threatens America’s National Security,” Take Part, June 6, 2013, http://​www​.takepart​.com/​a​r​t​i​c​l​e​/​2​0​1​3​/​0​6​/​1​0​/​c​l​i​m​a​t​e​-​c​h​a​n​g​e​-​n​a​t​i​o​n​a​l​-secu….

4 Joshua W. Busby, “Climate Change and National Security: An Agenda for Action,” CSR no. 32, Council on Foreign Relations, November 2007, p. v.

5 Kylie Schultz, “Experts Say Climate Change Is a Threat to National Security,” The International, April 3, 2013.

6 “National Security and the Threat of Climate Change,” CNA Corporation, 2007, p. 1.

7 “Quadrennial Defense Review Report,” Department of Defense, February 2010, pp. xv, 84–87.

8 Fiscal year 2013 federal government outlays of $3,685 billion.

9 Christopher Mann, “The Arctic Circle: Development and Risk,” paper presented at the “Unfrozen Treasures: National Security, Climate Change, and the Arctic Frontier” conference held at the National War College, Washington, May 13–14, 2008.

10 Thomas F. Stocker et al., eds., Climate Change 2013: The Physical Science Basis, Working Group I Contribution to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Summary for Policymakers (Geneva: IPCC, 2013), p. 2.

11 See, for example, Indur M. Goklany, “Misled on Climate Change: How the UN IPCC (and Others) Exaggerate the Impacts of Global Warming,” Policy Study no. 399, Reason Foundation, December 2011; Bjorn Lomborg, Cool It: The Skeptical Environmentalist’s Guide to Global Warming (New York: Knopf, 2007); and Patrick J. Michaels, ed., Addendum: Global Climate Change Impacts in the United States, Cato Institute, October 31, 2012.

12 M. L. Parry et al., eds. Climate Change 2007: Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge: Cambridge University Press, 2008), pp. 36–47. These predicted impacts are similar to those described in the Fifth Assessment Report published in draft form on March 30, 2014.

13 Future climate is projected by defining carbon emission scenarios in relation to changes in population, economy, technology, energy, land use, and agriculture—a total of four scenario families, that is, A1, A2, B1, and B2 are defined and used in the IPCC’s Third and Fourth Assessment Reports in 2001 and 2007, respectively. The A1 scenarios indicate very rapid economic growth, a global population that peaks in mid‐​century and declines thereafter, and the rapid introduction of new and more efficient technologies, as well as substantial reduction in regional differences in per capita income. Subcategories of A1 scenarios include A1FI and A1B, which represent the energy in fossil intensity and a balance across all sources, respectively. The A2 scenarios are based on a very heterogeneous world. The underlying theme is that of strengthening regional cultural identities, high population growth, and less concern for rapid economic development. The B1 scenarios are more integrated and more ecologically friendly than the A1 scenarios, with rapid changes toward service and information economies, and reductions in material intensity and the introduction of clean and resource‐​efficient technologies. The IPCC’s Fifth Assessment Report (AR5) to be released in 2014 will use Representative Concentration Pathways (RCPs). The four RCPs—RCP 2.6, RCP 4.5, RCP 6, and RCP 8.5— are named after a possible range of radiative forcing values in the year 2100 (2.6, 4.5, 6.0, and 8.5 watts per square meter, respectively), where RCP 8.5, RCP 6, and RCP 4.5 are roughly equivalent to A1FI, A1B, and A1B to B1 emission scenarios, respectively. The selected RCPs were considered to be representative of the literature and included a mitigation scenario leading to a low forcing level (RCP 2.6), two medium stabilization scenarios (RCP 4.5 and RCP 6), and one high baseline emission scenarios (RCP 8.5).

14 Ryan P. Crompton and K. John McAneney, “Normalised Australian Insured Losses from Meteorological Hazards: 1967–2006,” Environmental Science & Policy 11, no. 5 (2008): 371–78.

15 Sigridur Bjarnadottir, Yue Li, and Mark G. Stewart, “A Probabilistic‐​Based Framework for Impact and Adaptation Assessment of Climate Change on Hurricane Damage Risks and Costs,” Structural Safety 33, no. 3 (2011): 173–85.

16 Bjorn Lomborg, “Stern Review: The Dodgy Numbers behind the Latest Warming Scare,” Wall Street Journal, November 2, 2006. See also Yale Symposium on the Stern Review (New Haven, CT: Yale Center for the Study of Globalization, 2007); as well as Robert O. Mendelsohn, “A Critique of the Stern Report,” Regulation 29, no. 4 (2006): 42–46.

17 Nicholas Stern, Stern Review: The Economics of Climate Change (Cambridge: Cambridge University Press, 2007), p. vi.

18 Ibid., p. 156.

19 Indur M. Goklany, “What to Do about Climate Change,” Cato Institute Policy Analysis no. 609, February 5, 2008, p. 5. See also Indur M. Goklany, “Global Public Health: Global Warming in Perspective,” Journal of American Physicians and Surgeons 14, no. 3 (2009): 69–75.

20 A future world of very rapid economic growth, low population growth, and rapid introduction of new and more efficient technology. In that world, people pursue personal wealth rather than environmental quality.

21 Based on a very heterogeneous world. The underlying theme is that of strengthening regional cultural identities, having high population growth, and showing less concern for rapid economic development.

22 Goklany, “What to Do about Climate Change,” p. 14.

23 Very rapid economic growth, an emphasis on fossil fuels, a global population that peaks in mid‐​century and declines thereafter, and the rapid introduction of new and more efficient technologies, as well as a substantial reduction in regional differences in per capita income.

24 Goklany, “What to Do about Climate Change,” p. 23.

25 Parry et al., Climate Change 2007, p. 47.

26 National Research Council, National Security Implications of Climate Change for U.S. Naval Forces (Washington: National Academies Press, 2011), pp. 94–113.

27 Parry et al., Climate Change 2007, pp. 656–57.

28 “First Commercial Ship Sails through NorthWest Passage,” CBC News, November 28, 2008.

29 Robin McKie, “China’s Voyage of Discovery to Cross the Less Frozen North,” Observer (UK), August 18, 2013.

30 Christine Parthemore, “Climate Change and the Maritime Services,” in Broadening Horizons: Climate Change and the U.S. Armed Forces by Herbert E. Carmen, Christine Parthemore, and Will Rogers (Washington: Center for a New American Security, 2010), p. 27.

31 Arne Instanes et al., “Infrastructure: Buildings, Support Systems, and Industrial Facilities,” in Arctic Climate Impact Assessment, ed. Carolyn Symon, Lelani Arris, and Bill Heal (Cambridge: Cambridge University Press, 2005), pp. 907–44.

32 Pete Evens, “Arctic Thaw Heats Up Northwest Passage Dreams,” CBC News, September 13, 2012; Busby, “Climate Change and National Security,” p. 7.

33 Joseph F. Francois, Hugo Rojas‐​Romagosa, and Ana‐​Maria Vasilache‐​Freudenthaler, “Melting Ice Caps and the Economic Impact of the Northern Sea Shipping Lanes,” paper presented at the 16th Annual Conference on Global Economic Analysis, Shanghai, China, May 2013.

34 Donald L. Gautier et al., “Assessment of Undiscovered Oil and Gas in the Arctic,” Science 324, no. 5931 (2009): 1175–79.

35 Mann, “The Arctic Circle,” p. 3.

36 James Kraska, “International Security and International Law in the Northwest Passage,” Vanderbilt Journal of Transnational Law 42, no. 4 (2009): 1109–32.

37 National Research Council, National Security Implications, p. 3; “National Strategy for the Arctic Region,” White House, May 10, 2013, p. 3. Others argue that ratification of the UN Convention on the Law of the Sea will harm U.S. national interests. See, for example, Doug Bandow, “Don’t Resurrect the Law of the Sea Treaty,” Cato Institute Policy Analysis no. 552, October 13, 2005.

38 Robert Huebert, “United States Arctic Policy: The Reluctant Arctic Power,” University of Calgary School of Public Policy Briefing Papers, May 2009, pp. 1–2.

39 Ronald O’Rourke, “Coast Guard Polar Icebreaker Modernization: Background and Issues for Congress,” Congressional Research Service, July 24, 2013. The National Science Foundation has a smaller icebreaker, Nathaniel B. Palmer. It is a purpose‐​built ship for research, and its capability is more suited to the more benign ice conditions in the Antarctic Peninsula.

40 Ibid., p. 1.

41 Cost of $4.7 billion in 2011 dollars, inflation adjusted to $5 billion in 2013. U.S. Coast Guard, “United States Coast Guard High Latitude Region Mission Analysis Capstone Summary,” July 2010.

42 “An Analysis of the Navy’s Fiscal Year 2013 Shipbuilding Plan,” Congressional Budget Office, July 2012, pp. 18, 27.

43 O’Rourke, “Coast Guard Polar Icebreaker Modernization,” p. 25.

44 National Research Council, National Security Implications, p. 95.

45 Ibid., pp. 97–99.

46 Patrick L. Smith, Leslie A. Wickman, and Inki A. Min, “Broadband Satellite Communications for Future U.S. Military and Coast Guard Operations in an Ice‐​Free Arctic,” Crosslink 12 (Summer 2011): 12–17.

47 “Report to Congress on Arctic Operations and the Northwest Passage,” Department of Defense, May 2011, pp. 17–19.

48 Ibid., p. 25.

49 That figure is the average of the past five years’ military construction expenditures in Alaska. “Construction Programs (C-1),” Department of Defense Budget, Fiscal Years 2009–2014, Office of the Under Secretary of Defense (Comptroller), 2013.

50 National Research Council, National Security Implications, p. 50.

51 Ibid., p. 51.

52 “Arctic Operations and the Northwest Passage,” p. 10.

53 “National Security and the Threat of Climate Change,” pp. 6–7, 17

54 Ibid., p. 17.

55 Liana Sun Wyler, “Weak and Failing States: Evolving Security Threats and U.S. Policy,” Congressional Research Service, August 28, 2008, p. 6. See also Edward Newman, “Weak States, Failed States, and Terrorism,” Terrorism and Political Violence 19, no. 4 (2007): 463–88; as well as Justin Logan and Christopher Preble, “Washington’s Newest Bogeyman: Debunking the Fear of Failed States,” Strategic Studies Quarterly 4, no. 2 (2010): 17–38.

56 Henry A. Kissinger and James A. Baker III, “Grounds for U.S. Military Intervention,” Washington Post, April 8, 2011.

57 Wyler, “Weak and Failing States,” pp. 12–15.

58 Maxine Burkett, “In Search of Refuge: Pacific Islands, Climate‐​Induced Migration, and the Legal Frontier,” Asia Pacific Issues no. 98, East–West Center, January 2011, p. 3.

59 Jon Barnett and Michael Webber, “Accommodating Migration to Promote Adaptation to Climate Change,” Policy Research Working Paper no. 5270, World Bank, April 2010, p. 5.

60 Richard P. C. Brown, Gareth Leeves, and Prabha Prayaga, “An Analysis of Recent Survey Data on the Remittances of Pacific Island Migrants in Australia,” Discussion Papers Series no. 457, School of Economics, University of Queensland, March 2012.

61 Based on OECD 2011 data of 1,062,000, 210,000, and 40,000 immigrants for the United States, Australia, and New Zealand, respectively. If they were all to be resettled only in Australia and New Zealand, then Australia and New Zealand would need to lift their existing immigration levels by only 25 to 40 percent.

62 World Migration Report 2010: Executive Summary (Geneva: International Organization for Migration, 2010). One billion people reside in a country not of their birth.

63 Yearbook of Immigration Statistics: 2010 (Washington: U.S. Department of Homeland Security, 2011); Immigration Federation to Century’s End 1901–2000 (Canberra: Department of Immigration and Multicultural Affairs, Statistics Section, 2001); Facts and Figures 1998: Immigration Overview (Ottawa: Citizenship and Immigration Canada, 1998).

64 International Migration Database, OECD.StatExtracts, 2011. The database ignores illegal (unauthorized) immigrants.

65 “Economics of Adaptation to Climate Change: Synthesis Report,” International Bank for Reconstruction and Development/​World Bank, 2010, p. 19. The estimate sums the positive effects and negative impacts of climate change. The UN Framework Convention on Climate Change predicts annual adaptation costs for the developing world at $27 billion to $67 billion by 2030. See Investment and Financial Flows to Address Climate Change (Bonn: Climate Change Secretariat, 2007). For a discussion of the costs of climate adaptation, see Samuel Fankhauser, “The Costs of Adaptation,” Wiley Interdisciplinary Reviews: Climate Change 1, no. 1 (2010): 23–30.

66 OECD, Development Co‐​Operation Report 2012: Lessons in Linking Sustainability and Development (Paris: OECD Publishing, 2012), p. 268.

67 Goklany, “What to Do about Climate Change,” p. 20.

68 Gary W. Yohe et al., “Climate Change,” in Global Crises, Global Solutions, ed. Bjorn Lomborg (Cambridge: Cambridge University Press, 2009), pp. 254–57.

69 The United States produced 5.4 billion tons of CO2 in 2012. As a comparison, the price on carbon in the European Union and Australia is approximately $6 and $23 per ton of emitted CO2, respectively.

70 “Department of Defense Base Structure Report: FY 2013 Baseline,” Deputy Under Secretary of Defense, Installations and Environment, Department of Defense.

71 “National Security and the Threat of Climate Change,” p. 37.

72 Expenditure of $625 million in FY2013 for “Base Realignment and Closure,” Office of the Under Secretary of Defense (Comptroller), Construction Programs (C-1), Department of Defense Budget Fiscal Year 2015, March 2014.

73 Mark G. Stewart, Xiaoming Wang, and Garry R. Willgoose, “Direct and Indirect Cost and Benefit Assessment of Climate Adaptation Strategies for Housing for Extreme Wind Events in Queensland,” Natural Hazards Review (forthcoming).

74 “The Costs of Adapting to Climate Change for Infrastructure,” Discussion Paper no. 2, International Bank for Reconstruction and Development/​World Bank, August 2010, p. 38.

75 Mark G. Stewart, David V. Rosowsky, and Zhigang Huang, “Hurricane Risks and Economic Viability of Strengthened Construction,” Natural Hazards Review 4, no. 1 (2003): 12–19.

76 “Construction Programs (C-1).” Includes family housing costs of nearly $2 billion and assumes no additional consolidation of existing bases.

77 Lev Grossman, “Drone Home,” Time, February 11, 2013. More than a third of the aircraft in the U.S. Air Force’s inventory of aircraft are now unmanned.

78 “Quadrennial Defense Review Report,” p. 87.

79 Eugene Gholz and Daryl G. Press, “Energy Alarmism: The Myths That Make Americans Worry about Oil,” Cato Institute Policy Analysis no. 589, April 5, 2007, p. 2.

80 National Research Council, National Security Implications, pp. 41–43.

81 Ibid., pp. 39–40.

82 Busby, “Climate Change and National Security,” p. 1.

83 Lisa Daniel, “U.S. Military Remains Ready to Help Japan,” American Forces Press Service, April 11, 2011.

84 “National Security and the Threat of Climate Change,” p. 38.

85 National Research Council, National Security Implications, p. 39; USNS Comfort website, http://​www​.med​.navy​.mil/​s​i​t​e​s​/​u​s​n​s​c​o​m​f​o​r​t​/​P​a​g​e​s​/​d​e​f​a​u​l​t​.aspx.

86 National Research Council, National Security Implications, p. 5.

87 Ships cost $815 million each in 2002 dollars, inflation adjusted to $1.1 billion in 2013. The cost of converting 30‐​year‐​old amphibious ships to hospital ships is considerably lower (less than $300 million per ship). Neil Carey et al., “Future Deployable Medical Capabilities and Platforms for Navy Medicine,” CNA Corporation, February 2002, pp. 44–46.

88 Brett D. Schaefer, “Congress Should Renew the Report Requirement on U.S. Contributions to the U.N. and Reverse Record Setting Contributions to the U.N.,” WebMemo no. 3324, Heritage Foundation, July 22, 2011.

89 Médecins Sans Frontières, “Financial Report 2012: Key Figures,” 2012.

90 FY13 federal government outlays of $3,685 billion.