America's spy agencies are busy. They're leading the ongoing search for Usama bin Laden and other Al Qaeda leaders. They're trying to reduce the threat caused by terrorists aiming to attack our troops in Afghanistan and Iraq. And, soon perhaps, they may be keeping an eye on that well-known hot spot, the polar ice cap.

The House Intelligence Committee recently voted to require the government's spy agencies to write a report on the impact of global warming. These reports, called National Intelligence Estimates, are supposed to represent the collective wisdom of the major intelligence agencies on key national security issues.

But diverting the efforts of analysts and intelligence officials to study the weather is plain wrong, for several reasons.

For one, the intelligence community is supposed to focus on national security. That doesn't mean trying to child-proof the United States against every potential misfortune. It means focusing on protecting us from our enemies, and that means people.

These enemies may be from states, trans-states or no states. They may be abroad or here in the U.S. What they have in common is that they're threatening the United States by preparing to attack us somehow. Unlike criminals, national security threats are not in it for personal profit. They are out to get America and Americans. Properly defined, other dangers -- from illegal immigrants to diseases -- might be considered national security problems, but they are not national security threats.

There are good reasons not to dilute the definition of national security to include congressional pet projects. Government has many resources to deal with all kinds of problems. Resources, however, are not infinite. National security instruments should be reserved for the critical task of battling those people who plot how to kill Americas, undermine our economy and destroy our individual freedoms.

A second reason not to label every "danger du jour" as a national security threat concerns protecting the Constitution.

The Founding Founders recognized that in times of peril, the nation would have to rely on the executive to provide the leadership and resolve needed to deal with threats to the nation. That's why, for example, the president is vested with the authority to conduct foreign policy and act as commander-in-chief. The Constitution envisioned an executive who could wield significant power to act decisively in time of war or crisis.

That said, the president's national security powers should be reserved only for serious, imminent dangers from America's enemies. When Congress elevates the weather (or any similar concern) to the level of national security, it's encouraging the president to bring the extraordinary powers of the executive branch to bear on the problem.

This is a terrible idea -- one that could lead to a White House unilaterally dictating energy and environmental policies in the name of national security.

It seems remarkable that a Congress that's increasingly reluctant to allow the president to fight real enemies, whether that means battling Al Qaeda in Iraq or imprisoning terrorists at Guantanamo Bay, would be encouraging the administration to unleash the CIA on global warming.

There are times when national security instruments are used to do other things. And there are practical reasons for that. The Department of Homeland Security, for example, responds to transnational terrorist attacks, as well as to domestic natural disasters.

This is because the nation has only one emergency-response system. When a disaster happens, the same police and fire trucks show up, whether the disaster was man-made or heaven-sent. In times of crisis, we can't have first responders sit around and wait till an official determination is made as to whether an explosion or fire is the result of Al Qaeda or an accident.

As inexcusable as the vote of the House Intelligence Committee was, even more disturbing was a subsequent statement from the director of National Intelligence that he planned to use the nation's top spies to study global warming.

While the announcement may circumvent the debate over the measure in the Congress, it will put the U.S. intelligence agencies into the middle of a highly charged political and scientific debate on the causes, course and consequences of climate change.

The intelligence community and the other parts of government involved in national security should stick to hunting terrorists, thwarting rogue states, and dealing with the other serious enemies who spend their days and nights plotting against us. Leave studying the weather to the meteorologists at NOAA.

James Jay Carafano, Ph.D. is senior research fellow for national security at The Heritage Foundation and the author of G.I. Ingenuity: Improvisation, Technology, and Winning World War II.