"For years, too many of us have viewed global warming as simply an environmental or economic issue. We now need to consider it as a security concern," said Durbin. "Many of the most severe effects of global warming are expected in regions where fragile governments are least capable of responding to them. Failing to recognize and plan for the geopolitical consequences of global warming would be a serious mistake. This intelligence assessment will guide policymakers in protecting our national security and averting potential international crises."

"As I have said for many years, the way forward is to responsibly address the issue of climate change with a national strategy that incorporates economic, environmental and energy priorities. These issues are inextricably linked and changes to one will affect the other two. These priorities are also an integral part of U.S. national security," said Hagel. "Risk assessment is essential to putting our national resources in the places where they will be most effective. This is even more important when assessing risk to national security. This legislation will provide information we need to continue to help make our country secure in the years to come."

A National Intelligence Estimate is a comprehensive review of a potential security threat that combines, correlates and evaluates intelligence from all of the relevant U.S. intelligence agencies. Various intelligence agencies - the CIA, NSA, the Pentagon, FBI, etc. - must pool data, share perspectives and work together to assemble an accurate picture of threats to U.S. security.

The two senators said an NIE is essential to accurately compare and contrast strategic intelligence gathered by different intelligence agencies. Without an NIE, the various agencies may never have an opportunity to examine each other's data, and any differences or similarities between the reports could provide important information for policymakers.

Durbin and Hagel's bill, the Global Climate Change Security Oversight Act, asks the intelligence community to provide a strategic estimate of the risks posed by global climate change for countries or regions that are of particular economic or military significance to the United States or that are at serious risk of humanitarian suffering. This National Intelligence Estimate will assess the political, social, agricultural, and economic challenges for countries and their likely impact.

Environmental changes caused by global warming represent a potential threat multiplier for instability around the world. Scarce water, for example, may exacerbate conflict along economic, ethnic, or sectarian divisions. Water shortages, food insecurity, or flooding - all of which may occur as a result of rising global temperatures - could also displace people, forcing them to migrate. The NIE will look beyond the short-term and require the intelligence community to analyze these issues in the context of the next thirty years. The legislation will also fund additional research by the Department of Defense in order to examine the impact of climate change on military operations.

A number of military and intelligence experts agree that the Durbin-Hagel bill will serve a critical role in protecting U.S. security interests. "This bipartisan legislation takes on an important emerging policy issue- the impact of climate change on national security," said Gen Charles F. Wald, former Deputy Commander of Headquarters U.S. European Command. "I support its call for a National Intelligence Estimate of the topic and authorizing the Secretary of Defense to conduct further research on the military impact of climate change." General Wald is a member of a high level military advisory board studying potential national security impacts of climate change with the Center for Naval Analyses. The report will be released later this Spring.

Last year, the Bush Administration also acknowledged that environmental issues pose national and international security challenges. The President's 2006 National Security Strategy stated that "environmental destruction, whether caused by human behavior or cataclysmic mega-disasters such as floods, hurricanes, earthquakes, or tsunamis. Problems of this scope may overwhelm the capacity of local authorities to respond, and may even overtax national militaries, requiring a larger international response. These challenges are not traditional national security concerns, such as the conflict of arms or ideologies. But if left unaddressed they can threaten national security." The National Security Strategy is a comprehensive report to Congress laying out the broad strategic vision of the President for the security of the U.S.