Environmentalists should be pretty excited about having Janet Napolitano as Secretary of Homeland Security—and not because, as Ed Rendell so awkwardly noted, she's single and will have more time to spend on the job. As the governor of Arizona, Napolitano has been forced to consider the impacts that immigration—and attempts to stop immigration—are having on wildlife in the border region. And she's had the sort of firsthand border experience that makes her question the utility of the security fence that's currently under construction along several sections of the border. This skepticism is good news, because even if a border fence is unlikely to stop immigrants, it does have potential to do some serious environmental harm.

What sort of harm? The fence has already caused flooding in Organ Pipe Cactus National Monument, where the water drainages flow from north to south, across the border, and the fence acts as a dam when it rains. More significantly, the fence threatens to impede the migration of wildlife, especially the endangered jaguar, which is starting to make a comeback in southern Arizona. And some sections of the fence currently under construction will channel human migrants into more remote—and more sensitive—areas, increasing the already-significant environmental impact of having hundreds of thousands of people walk across the border each year.

None of these environmental impacts have been taken into account in border-fence construction decisions, because the Real ID Act of 2005 gave the secretary of Homeland Security the power to bypass the standard environmental review process in order to expedite construction of the fence. The Bush administration and its congressional allies have argued—pulling the ever-baffling "terrorists are sneaking over our border" card—that waiving the environmental review process is a necessary sacrifice for the sake of national security. Conservation groups like the Sierra Club have filed several lawsuits in which they (unsurprisingly) beg to differ. But they've lost these cases, and the Supreme Court recently declined to hear one of their appeals.

Now that Napolitano is going to be Secretary of Homeland Security, border fence construction is likely to slow. The construction that does happen will probably get held to the same environmental standards as any other federal project. This will probably mean a lot less physical fencing and a lot more high-tech "virtual fence" gadgetry, like motion-sensor cameras and infrared detectors. The coolest potential side benefit? Those cameras could be rigged to take pictures of jaguars as well.

--Rob Inglis, High Country News