Global warming can significantly exacerbate security challenges facing the nation. Previous commentaries addressed global warming problems within the United States caused by water and storm issues, including floods and firestorms and forced shifts in population and agricultural patterns. The extent to which these natural challenges will be exacerbated by global warming remains controversial, but there are a number of actions which the United States can take now that would make sense in their own right and would significantly improve the nation's ability to address whatever global warming impacts actually arise. The challenges in regard to security are more difficult. Temperature increases can raise sea levels, melt ice sheets and glaciers, alter rainfall patterns, intensify storms, and widen the range of life-threatening diseases. As an assessment by senior military officers noted, there is a range of estimates on how severe these effects will or will not be, which basically translates to a range of risks which must be addressed. So their conclusions and recommendations are not tied to specific projections, but rather to appreciate the scope of security implications and develop approaches to mitigate them.

The challenges are complicated by two major concerns. First, there is a double layer of uncertainties, not only what the effects of global warming will be, but how populations and countries will respond to them. Just as importantly, mitigation is not a task for the United States, but for the entire international community. On the positive side, as with mitigation of domestic effects, there are many actions which could be taken - indeed, many of them are already in process - to significantly improve the global ability to address whatever impacts actually arise.
 
 
MELTING ICE
 
 

Generally, melting ice is important for the indirect effect of rising sea levels. There are, however, two specific direct effects which could result in conflicts.

The first is a significant decrease in the Arctic ice cap, one of the few unequivocal impacts of global warming which has a conflict potential. Interestingly enough, this is not from possible calamities (except, maybe, for polar bears), but from emerging advantages:

• Arctic shipping lanes are becoming more and more accessible. A recent assessment by the Arctic Council sees the Arctic Ocean being ice free in the summer as early as 2015. This will result in a significant increase in Arctic shipping, but at relatively high risk: experienced Arctic mariners are in short supply, hydrographic data is inadequate, support facilities are widely spaced, and emergency response capabilities are sparse. Coastal states are generally responsible for providing non-discriminatory control regulations, and there is already international coordination through the Arctic Council. Conflict seems unlikely, but there is a clear need for expanded patrol capabilities.




• Heightened accessibility of Arctic areas will greatly increase the potential to exploit sea bed resources. A recent technical survey showed a high probability of 44 billion barrels of undiscovered oil and 770 trillion cubic feet of undiscovered gas -- much of the oil in Alaska while a large portion of the gas in the Russian Arctic. But the Arctic Ocean is relatively small, with little or no space for international waters. Russia has laid claim to roughly half of the Arctic seabed, based partly on the reach of its continental shelf. It has planted a Russian flag on the seabed at the North Pole and has expressed its readiness to defend claims militarily, so there is a clear potential for conflict.

The Arctic region is not currently governed by any comprehensive multilateral norms and regulations because it was never expected to become a navigable waterway or a site for large-scale commercial development. The UN Convention on the Law of the Sea provides mechanisms for states to settle boundary disputes and submit claims for additional resources beyond their exclusive economic zones. The convention also allows states bordering ice-covered waters to enforce more stringent environmental regulations, and it defines which seaways are the sovereign possessions of states and which international passages are open to unfettered navigation. However, the Arctic includes a number of vexing problems that do not allow for a neat application of this legal framework. Since the United States has not ratified the convention, it cannot formally assert any rights to the untold resources off Alaska's northern coast beyond its exclusive economic zone -- such zones extend for only 200 nautical miles from each Arctic state's shore -- nor can it join the UN commission that adjudicates such claims. Worse, Washington has allowed its icebreaker fleet to atrophy so it is difficult to even maintain a presence. Yet, decisions made by Arctic powers in the coming years will shape the future of the region for decades. Without US leadership, the region could erupt in an armed mad dash for its resources. Now, while the situation is still in flux, is the time to mount diplomatic efforts to resolve the territorial and resource issues.

The other direct effect is glacial melting, which can have a direct impact on regions where the melt is a major water source. Northern India is the world's most intensively irrigated region, hosting 600 million people, and is already facing severe problems from groundwater depletion. Added to this is a concern over potential shrinking of Himalayan glaciers which provide water to northern India, Nepal and China. Similarly, a European Union report warns of potential conflict in Central Asia over disappearing glaciers. These concerns, however, are muted by recent evaluations that the Himalayan glaciers may no longer be retreating.

In regards to Himalayan area, India-China border talks have been going on for years. Neither side seems inclined to return to active hostilities, but there has not been any noticeable movement towards resolution of the underlying issues. The United States, which has good relations with both countries, is certainly in a position to encourage more active dialog before any real pressing issues arise.
 
 
COASTAL FLOODING
 
 
Coastal areas face a double threat: rising sea levels and intensified storms. Some sea level rise is expected simply from thermal expansion of ocean water, along with water input from retreating glaciers. Potential catastrophic rises are generally attributed to one of two eventualities. The first is melting of the Greenland ice cap, which could raise sea levels by 20 feet; however, current estimates show that this would take centuries and the near term rise will probably be only inches. The second is the collapse of the West Antarctic Ice Shelf, which could also raise sea levels by 20 feet. But present assessments show that this would require a local temperature increase of about 5 °C and take several thousand years. Overall, it seems very unlikely that sea level increases would reach catastrophic levels in the coming century.

But the most recent estimates do show a global rise of up to one meter is likely by 2100. Today, about 60 million people live within 1 meter of mean sea level; much of this population lives in the nine major river deltas in south and southeast Asia. Parts of countries such as Bangladesh, along with some island nations like the Maldives, would simply be submerged. According to a report by the European Environment Agency, a one-meter rise in sea level would affect 13 million people in five European countries and destroy property worth $600 billion, with the Netherlands the worst affected. Of course, none of this is certain, but it raises a serious potential for major disruption of coastal areas.

The impact of global warming on tropical storms has not been quantified. But a recent review by the National Oceanic and Atmospheric Administration concluded that "it is likely that greenhouse warming will cause hurricanes in the coming century to be more intense on average and have higher rainfall rates than present-day hurricanes." At least there does not seem to be any relationship between global warming and storm frequency, but more intense storms mean both higher wind speeds and storm surges, and so higher risk in coastal area.

An immediate concern is with small island nations. Tuvalu, for example, has a maximum land elevation of about 15 feet, so a storm surge could cover the entire island. In recent years, regular "king tides" have been rising higher than ever. Waves have washed over the island's main roads; coconut trees stand partly submerged; and small patches of cropland have been rendered unusable because of encroaching saltwater. The government and many experts already assume the worst: Sometime in the next 50 years, the entire 11,800-strong population might have to be evacuated. The situation, however, is ambiguous. Tuvalu itself may simply be sinking. While tide gauges indicate that the sea level is actually rising, the gauges themselves have questionable accuracy; reliable satellite data extends back only a few years. Although the cause may not be clear, the result is -- the sea is encroaching more and more on Tuvalu, and the same holds true for other Pacific islands. The disappearance of some island nations would also raise questions of sovereign ownership of areas of the sea floor.

A few drainage and sea wall projects have begun on some individual islands, but their regional potential is very limited. Tuvalu is actually in a comfortable position, as New Zealand has agreed to accept its population in the event its land disappears, and is actually accepting a yearly quota of refugees. Australia has also indicated it would help resettle climate change refugees as a last resort. This is a fairly simple solution for island countries with quite small populations, but the total population of the Pacific islands alone is nearly 10 million people.

The potential refugee problem is even worse with countries which have large, low-lying coastal areas. Bangladesh is probably the worst case; ninety percent of the country is flood plain and supports some 140 million people. Already a million people a year are displaced by loss of land along rivers, and indications are this is increasing. A one-meter sea level rise would inundate more than 15 percent of the country, displace more than 13 million people, and cut into the crucial rice crop. Refugees would have very few places to go inside Bangladesh; many Bangladeshi Muslims would undoubtedly seek to flee into Hindu India, with an obvious potential for ethnic conflict.

Bangladesh has a history of severe cyclone damage. Cyclone Bhola in 1970 killed a half million people. But the toll for Cyclone Sidr in 2007 was only several thousand, thanks to the fact that the country's early warning and preparedness systems had improved considerably. There were systematic evacuations of over 3 million people in the days before the storm hit; stockpiled relief supplies and rescue equipment greatly aided the recovery. This demonstrated the effectiveness of preparations in the face of specific storms, but does little to address the potential crisis if millions of people are displaced along with a reduced capacity for food production. Assessments of potential sea walls and dikes in this land of shifting river courses and mud flats show little potential for any large-scale mitigation of risks. To its credit, Bangladesh has initiated a fairly successful population control program, reducing the fertility rate from 6.2 thirty years ago to 3.2 in 2003 and helping to reduce the scope of any future refugee crisis.

India faces its own global warming challenge. Agriculture in the north part of the nation has already been mentioned. But a one-meter sea rise would affect some seven million people. These would basically be Internally Displaced Persons (IDP) as they would be unlikely to cross out of India but could certainly destabilize the country. And they would complicate India's handling of any refugees from Bangladesh, increasing the potential for armed conflicts. On India's west coast, Mumbai, with 17 million people, is India's largest and most economically important city. Because it has numerous flood prone areas, no protective dikes, and weak disaster preparedness, Mumbai is particularly vulnerable to climate change.

Several of China 's major cities (Hong Kong, Shanghai & Tianjin) lie in low elevation coastal zones vulnerable to sea level increases and major storms. Shanghai, China's commercial center and its most populous urban area with over 16 million people, has an average of only a four-meter height over sea level. Heavy exploitation of ground water has also resulted in land subsidence, exacerbating the city's flood vulnerability. On the other hand, there is an extensive series of dikes and flood walls. But the city experiences frequent typhoons - flooding from one in 1994 destroyed many of the dikes and affected almost 14 million people. Overall, the severity and frequency of heavy rains, land subsidence, flood-prone areas, and many poorly constructed buildings leave Shanghai vulnerable to climate change and coastal erosion. So with Shanghai alone there is a potential for several million IDPs. One disturbing possibility if China ends up with many millions of IDPs in an already densely populated country, is conflict with Russia over the sparsely populated areas of Siberia - areas which could become much more habitable if global temperatures do rise.

A number of other major world cities are also at risk for coastal flooding and storm impacts, including Rio de Janiero, Tokyo, Jakarta, and Bangkok. Generally, displaced persons from these cities do not have an obvious potential to spark international conflicts, though they could certainly destabilize their own nations.

Africa is also a concern. Northern Egypt with Cairo, although not vulnerable to oceanic typhoons, is a low-lying zone vulnerable to sea level rises. Combined with a potential reduced flow of the Nile, this could disrupt over fifty million people in a very unstable part of the world. West Africa is also at some risk for coastal storms and flooding.

Overall, the threat of coastal flooding poses major risks for several nations, even without the added impetus of global warming. Their experience does show the importance of disaster preparations, particularly for transient storms. At least, storms strike suddenly, but any sea level rise will take place over some number of years, giving time for nations to react. Shanghai stands out as one of the few places outside Europe and North America where there is some actual planning for protection against rising seas; the experiences of the Netherlands and of Venice show that real protection is both difficult and very expensive. Although refugee situations could lead to conflicts, there is no obvious role for the United States, and certainly not for military forces. Once conflict does break out, diplomatic solutions may be very difficult to find. So the major role the United States can play at this point is to encourage diplomatic discussions (as now ongoing between India and China and as are taking place with the Pacific island nations). The United States can also support the development of emergency responses capabilities to increase the resilience of threatened states. Population control is also important, and both China and Bangladesh have systematic programs in this area.
 
 
WATER RESOURCES
 
 
Water is essential for life and is already scarce globally -- some one billion people are without reliable access to clean water. With global warming many of them could be without any access to water at all due to changing rainfall patterns and shrinking glaciers. However, projecting water flows is even more difficult that sea level rises and is complicated by projected temperature rises. Some areas -- much of Canada and Siberia -- may benefit from increased ranifall and higher temperatures. But benefits to these sparsely settled areas would be dwarfed by devastation in heavily populated temperate and tropic zones. There, lower rainfall and higher temperatures in existing agricultural areas may face tens of millions with starvation.

Indeed, the world is already facing a food crisis. A Comprehensive Assessment of Water Management in Agriculture by 700 scientists and water professionals concluded that current food production and environmental trends will lead to crises in many parts of the world. In Asia, the larger countries avoided famines in the 1970s and 1980s only because they built giant state-sponsored irrigation systems and introduced better seeds and fertilisers. But the extra 1.5 billion people expected to live on the continent by 2050 will double Asia's demand for food. The continent faces a combination of very little new land left for cultivation, an increasingly unpredictable climate, and water supplies already stretched to the limit. To complicate the situation, water tables in parts of India and China have dropped catastrophically in the last few years. In adjacentPakistan, farming is heavily dependent on irrigation. An assessment on Africa notes that small-scale farming provides employment for 70% of working people, and this farming is overwhelmingly dependent on direct rainfall. Its problems are exacerbated by widespread poverty, recurrent droughts and floods, a heavy disease burden, numerous conflicts, and astoundingly bad governance. Recurrent famines are largely a function of the failure of institutions, organizations, and policies; the causes are diverse and so are potential policy responses. Particularly in the Sahel, recurrent droughts have a potential for disaster. In one immediate example, Kenya has just been hit by mass hunger as well as shortages of power and water. The immediate cause is a prolonged drought, but critics of Kenya's dysfunctional coalition government blame it for failing to mitigate the drought's effects, in spite of clear warning signs. At least, a World Bank study of Latin America, shows that the situation at present is decidedly better. Primary agricultural sector accounts for about 25% of employment, though rural poverty is widespread and tied to the existence of very small farms and little investment in human capital and infrastructure. Food supply is generally adequate.

Current environmental challenges coupled with projected population increases put all three of these continents at considerable risk. Famines in particular could badly destabilize governments and result in major refugee flows. The Comprehensive Assessment of Water Management in Agriculture provides seven imperatives for water management; they all involve better coordination among existing groups, including government agencies. The assessment on Africa concluded that strategies to increase human resilience must be central; it focuses on local needs and stresses cooperative efforts and increased support for small-scale agriculture. A ministerial conference identified the starting point as "developing a common awareness and understanding among...decision-makers." Specific elements addressed water policies, trade, and research and implementation of irrigation methods. Similarly, the World Bank study of Latin America stressed the need to improve natural resource management systems and to enhance social safety nets and markets for land and water. Although some of these assessments specifically addressed global warming, their recommendations were measures which should be taken anyway to address current challenges.
 
 
OTHER CONCERNS
 
 
Interior flooding is also a real challenge, especially in the face of changing rainfall patterns. On the positive side, such flooding is typically episodic and temporary, But it can also destroy critical local facilities and wide areas of farmland, generating at least Internally Displaced Persons and unrest. As with similar challenges in the United States, there is a need to assess vulnerabilities on a regional basis and reinforce protective measures and response capabilities.

Health challenges are also rising as temperature changes can increase the areas of vulnerability for such diseases as malaria, while flooding, food shortages, and refugee flows can significantly increase the potential for diseases to rapidly spread among vulnerable populations.

Demographics is a major complication. Even without global warming, areas that are now marginally stable will become unstable due to population pressures. According to the latest data, global population will reach 7 billion by 2011, with virtually all of the growth in developing countries; the growth of the world's youth population (ages 15 to 24) is shifting into the poorest of those countries. Africa's population has just passed 1 billion and is expected to double by 2050. Such numbers will unavoidably lead to major refugee flows and resulting conflicts, particularly since Africa already has almost 12 million Internally Displaced Persons (IDPs).

In Asia, China and Bangladesh have both implemented policies designed to limit population growth. For China, its one-child policy, in effect since 1979, is expected to stabilize the population at 1.4 billion (slightly above current levels) by 2030. However the rapid growth of its older population poses significant challenges and will likely result in some loosening of its policies. By 2040, its population will probably be surpassed by India. India has been slower than China to implement population controls. One result is that India now had a larger proportion of working age adults. But India's Population Commission is hard at work on stabilizing India's population so that it will probably level off by mid-century. Pakistan also has a high proportion of working age adults, but it is unclear if the country will be able to take advantage of this situation by providing work for them. As many as 60 million Pakistanis are now "food insecure," mainly due to its high rate of population growth. Its agriculture is highly dependent on irrigation, so water shortages would significantly inhibit the country's ability to feed itself. The government has recently stressed programs to reduce the high population growth rate, specifically so that it does not nullify socio-economic gains, but its growth rate sill remains significantly higher than India's or China's.

Overall, population growth remains high in the most vulnerable areas of the world, greatly complicating efforts to improve local situations.
 
 
US STRATEGIC ASSESSMENTS
 
 
There have been two authoritative assessments of the impact of global warming on US security.

The first, by a Military Advisory Board of eleven retired generals and admirals, assessed the impact of global climate change on key matters of national security and concluded that climate change acts as a "threat multiplier" for instability in some of the most volatile regions of the world. Their first recommendation was that effects of climate change be incorporated into national strategic planning. In their view, the United States needs to commit to a stronger international role to help stabilize climate change at levels that will avoid significant disruption to global security and stability, including helping less developed nations build the capacity and resiliency needed to manage climate impacts. In regards to the direct military effects, the board recommended that the Department of Defense improve its energy efficiency to reduce greenhouse gas emissions and assess the direct impact of global warming on military installations. The report outlined in some detail effects such as those discussed above and addressed the potential for mitigation and adaptation. The only direct application of military forces to address the challenge was to help with stability operations, capacity building, and disaster response. Security cooperation programs can also help increase the capacity of local military forces to support civilian government agencies.

The other noteworthy assessment, provided to the House of Representatives by the National Intelligence Council, concluded that the most significant impact on the United States would be the indirect results of climate-driven effects on other countries. These impacts will worsen existing problems such as poverty and social tensions, threatening domestic stability in some states and potentially contributing to conflict, particularly over water resources. This assessment also commented on many of the effects discussed above. Security implications for the United States include the need to be prepared for increased immigration pressures and humanitarian emergencies. Important regional states may be negatively impacted, leading to political change or disruption. Building on this, retired Vice Admiral Lee Gunn also testified to Congress that global warming means that America's men and women in uniform will be called on increasingly for humanitarian relief and disaster assistance operations. With its direct impact on US military facilities and logistics operations, global warming will also force changes in military operations, while loss of sea-ice will likely increase commercial and military activity in the Arctic. This requires US leadership and action on a global scale.
 
 
SUMMARY
 
 
First of all, the Arctic is a special case. The ice cap diminishing and potentially disappearing means that issues of sovereignty need to be addressed on a multilateral basis, with the UN Convention on the Law of the Sea providing the most attractive vehicle. This is also true for sovereignty issues in connection with disappearing island nations. The United States needs to join this convention and take an active part in an such discussions and also needs to expand its capacity to operate in the region.

Globally, conflict is likely over resource disputes, particularly involving water, food and refugee flows. Present trends, including population growth, make this inevitable; there are already significant refugee flows even without global warming. Global warming pressures exacerbate these existing pressures and could result in catastrophic situations, both from a security point of view, as well as from a humanitarian point of view.

For the United States, the major impact will be severe disruptions in the global economy, which underlies US prosperity, particularly in the context of growing globalization. The United States simply cannot prosper in a world of turmoil. The only feasible long-term option is to promote a world of prosperity, and this inevitably means nation building. The United States has avoided this task, rationalizing that it is not the US responsibility to fix everyone else. The world has also been wary of US efforts to expand its influence; many countries have been less than enthusiastic about US assistance programs. Unfortunately, US assistance has too often supported poor governments and has had at best modest impact at the grass roots level. Nevertheless, the development of a world which can more effectively cope with global challenges is critical to the long term well being of the United States.

The United States obviously cannot do this alone, but there is no other nation capable of supplying the leadership needed to accomplish this. The good news is that population growth and global warming, the key drivers of potential turmoil, are both gradual effects, allowing some time to build new capacity. Some time, but not a lot of time. Prosperity, like democracy, cannot be forced. But it can be encouraged, promoted, and supported. Although prior US programs have left much to be desired, the Millennium Challenge Corporation now has broad experience in using aid to promote not only development but good governance.

The European Union has come to similar conclusions that it must devise urgent strategies to deal with the consequences of climate change, as the risks posed by climate change are real and its impacts are already taking place. The first requirement is to build up EU capacities across the board: from monitoring and early warning, to conflict prevention, crisis management and disaster response. In all its relationships - from Africa to the Middle East, from Latin America to Central Asia and beyond - the EU needs to raise awareness about the security effects of climate change and build capacity in those countries that will be hit hardest.

The United States also faces the potential for direct impact of refugee flows, particularly from Latin America both overland and by sea. Military assets, including the Navy and Coast Guard, could help to address such eventualities, but cannot begin to address the underlying cause: poverty and poor governance at home. Mexico, as the bordering country most directly involved, has significant oil wealth, but little of this has been used to promote social and economic development and the United States has done little to pressure and assist the Mexican and other Latin American governments to focus attention on their own national development.

For conflicts elsewhere in the world, any role for US military forces is problematic and situations will be extremely difficult to address once they are in a crisis mode. There is little military assets can to do address this broad challenge to US well being. Rather, it is essential to promote wide ranging cooperative and intergovernmental programs now which can provide rational approaches to existing problems of water and agriculture and a framework for addressing the more taxing problems which will surely arise. This will require an integrated application of the entire range of US national assets. Unfortunately, the United States is poorly organized to develop such an effort. Its national strategy is myopic and only developed piecemeal. There is a National Security Strategy, based on the Department of Defense's Quadrennial Defense Review (the latest version now in progress); the Department of State has recently begun a parallel Quadrennial Diplomacy and Development Review. But both of these are departmental efforts. There is still no government element responsible for developing an overall national strategy, and that is what is needed to address the challenge of global warming with a program of global development.

It is also difficult for the United States to promote development and democracy abroad when it is doing only a passable job at home. Indeed, a major reason why the nation is faced with a severe immigration challenge is the failure to provide living wages to millions of essential workers in the national economy, with a resulting pressure to use illegal aliens to act as a necessary underclass. The United States urgently needs a surge at home to develop the type of transparent, prosperous society that can serve as an example to the world.

None of these actions depend on the extent to which global warming may be caused or exacerbated by human actions. Continuing research to develop efficient mitigation strategies and integrated efforts to implement them are important. But it is equally or more important to build resilience, a capacity to address new challenges, not only at home but globally.