Global Warming: What You Need to Know

The Basics

National Security and Global Stability in a Warming Climate

In many areas of the world, resource availability is likely to be seriously impacted by a warmer climate. At the same time, sea-level rise and other climate-related events such as drought and desertification may lead to population displacement and large-scale migrations, particularly from poor nations least able to adapt to the worst impacts of climate change. These scenarios pose serious risks from a national security standpoint. Recently, some of the nation’s most respected retired military officials studied how global warming could affect U.S. national security over the next several decades. Among other things, they determined that:

The report recognized that when environmental conditions deteriorate significantly, or when a climate changes enough to alter resources, societies become stressed, causing tension and leading to instability. The authors focused on four major impacts of climate change that lead to destabilization: reduced access to fresh water, impaired food production, health catastrophes, and land-loss and flooding.

Reduced Access to Fresh Water

The Intergovernmental Panel on Climate Change (IPCC) predicts that water availability may decrease by 10-30% over some dry regions of the world by 2050. In Africa alone, the IPCC estimates that up to 600 million people will experience water stress and will be at risk for hunger by 2050. Most countries in the Middle East and northern Africa are already considered ―water scarce,‖ and by 2025 large parts of China, India, and other countries are predicted to face deficiencies as well.

The most direct effect of climate change to be felt in the Middle East is likely to be a reduction in precipitation, exacerbating dry land areas and reducing key river flows. Jordan and Israel already face water shortages, and approximately two-thirds of Arab nations depend on non-domestic sources for their fresh water supply. Tensions over water resources already exist in some places in the Middle East, and enhanced by climate change, severe water scarcity in this politically volatile region has major implications for security.

Impaired Food Production

Food and crop production will be impacted by global warming in a variety of ways. There is wide consensus that climate change will worsen global food security, although localized impacts will differ across regions of the globe. Mid and high-latitude regions of the world could see an increase in crop productivity for temperature increases up to 3°C, but beyond that range, productivity is predicted to decrease all over the world. Even at very small temperature increases (1-2°C), crop productivity is expected to decrease in regions that experience wet-dry seasonal patterns: Southeast and Central Asia “It’s not hard to make the connection between climate change and instability, or climate change and terrorism.” – General Anthony C. “Tony” Zinni, U.S. Marine Corps (Ret.) Former Commander-in-Chief of U.S. Central Command 6 could experience a decrease in crop yields as large as 30% by 2050. A reduction of this scale raises serious humanitarian concerns, and would result in immeasurable impacts on the well-being of local populations and have implications for the global economy.

Conflicts over scarce food resources and arable land occur today. The most well-known example is probably land competition between farmers and herders in Darfur. Less than 40% of the Darfur region of Sudan contains permanent crops and arable land and is stricken with famine. Extended droughts in the region have resulted in the loss of both farmland and grazing land, causing conflict between the groups who use land for those separate purposes. In combination with political instability, population growth, and ethnic and religious differences, land conflicts have led to violence that has threatened entire regions and instigated international action. Violence in Darfur is a striking example of how climate-related events can escalate social tensions in existing areas with scarce resources.

Health Catastrophes

The IPCC projects that climate change-related exposures will likely affect the health of millions of people, especially those populations with low adaptive-capacities. Predicted impacts include:

• Increases in malnutrition and consequent disorders;
• Increased deaths, disease, and injury due to heat waves, floods, storms, fires and droughts;
• Increased burden of diarrheal diseases;
• Increased frequency of cardio-respiratory diseases due to higher concentrations of ground-level ozone; and
• Altered space-distribution of certain infectious disease vectors.

The changing ranges of and increases in infectious diseases due to climate change have received much attention in the health policy arena. The World Health Organization (WHO) has found that disasters such as floods can increase the transmission of both water-borne and vector-borne diseases like typhoid fever, leptospirosis, hepatitis A, malaria, yellow fever, and West Nile Fever. Additionally, mosquitoes carrying malaria and dengue fever have been found increasingly at higher altitudes and latitudes, jeopardizing communities that have had little experience with tropical disease and that lack adaptive capabilities.

Large-scale health emergencies or disease epidemics can quickly escalate to regional or global security threats. These types of challenges have the potential to require military support on several levels – ranging from assistance in distribution of medicines and vaccines to peacekeeping and stabilization activities.

Land Loss and Flooding: Displacement of Major Populations

Coastal and low-lying areas all over the world are expected to be exposed to increasingly high risks such as sea-level rise and coastal erosion. The IPCC estimates that with a temperature rise of just 2°C, millions more people will experience coastal flooding each year. Densely-populated and low-lying deltas, as well as small islands, are especially vulnerable to these risks. A recent analysis found that 300 million people inhabit 40 deltas around the world, and by 2050, one million people in just three major deltas (the Ganges-Brahmaputra delta in Bangladesh, the Mekong delta in Vietnam and the Nile delta in Egypt) will be directly impacted by land loss and coastal erosion. As with other impacts of climate change, the most affected populations will be developing nations with low adaptation capacity.

From a national and global security perspective, the most serious implication of land loss due to rising sea levels (and other impacts that cause regions to become uninhabitable) is the possibility of mass migrations. Also known as environmental refugees, displaced populations due to uninhabitable land, ecological devastation, lack of resources or extreme weather events can move within a country, across international borders, and in some cases across the world. The effects of such large-scale population movements have the potential to be highly destabilizing to the global community unless they are carefully managed. In 1995, there were 25 million environmental refugees, a number almost equivalent to conventional refugees at the same time. Under unmitigated climate change, this number has the potential to increase rapidly; some estimate there could be as many as 50 million environmental refugees by 2010. Sea-level rise and flooding, as well as resource competition as a result of climate change, will most likely exacerbate current refugee numbers, raising concerns over border control and immigration laws.

No Longer Just an Environmental Issue

After examining the above climate impacts as related to political and societal destabilization, the retired military officials’ study made the following findings:

1. Projected climate change poses a serious threat to America’s national security;
2. Climate change acts as a threat multiplier for instability in some of the most volatile regions of the world;
3. Projected climate change will add to tensions even in stable regions of the world; and
4. Climate change, national security, and energy dependence are a related set of global challenges.

The U.S. can longer consider global warming solely a domestic environmental issue. It is clear that the impacts of unmitigated climate change will have serious consequences on multiple levels, making the case for action from a national and global security perspective. To avoid the worst impacts of climate change in the future, the United States needs to be an international leader today. This leadership entails the enactment of a mandatory domestic cap on greenhouse gases, full participation in binding international agreements to curb global warming, and partnerships with both developed and less-developed countries to help vulnerable nations build adaptation capacity.

Next: Intergovernmental Panel on Climate Change