05/24/2010 02:00 pm ET | Updated May 25, 2011

Reconnecting the World

As climate disruption accelerates, natural systems are our first line of defense.  Ecosystems can adjust to -- and help human communities weather -- chaotic climate. But they can do so only if we give them space -- connected space.

We're beginning to learn how to do this, and we had two wonderful examples last week.

The further advanced is the Obama administration's embrace of a Sierra Club initiative to reconnect the severed halves of the Everglades ecosystem by converting the Tamiami Trail viaduct -- which is currently a dam that splits the Glades and cuts off water flow to the southern half -- into a bridge under which the natural flow of water can be restored. 

The Club has been working on this vision for years, and in 2009 real progress began when ground was broken on a one-mile bridge that would allow a portion of the natural water flow to resume.   But the real breakthrough came on Wednesday when the Obama administration announced that it was going to expand the "skyway" project to encompass four additional bridges, thereby opening up an additional 5.5 miles of water flow.

Jonathan Ullman, the Sierra Club leader who has championed the Everglades Skyway from its inception, summed it up quite simply: "This is huge...The Everglades now has a fighting chance."

Of all the shackles that industrial civilization puts on natural systems, roads are the most pervasive and one of the most destructive. (I'd put dams and levees at the top of the list.)   And if we are going to rely on natural systems to help us get through the climate disruption we have unleashed, we will need to rethink and reengineer these huge barriers.  And demonstrating  that an important highway (which the Tamiami Trail certainly is) can be redesigned to restore, instead of dam, natural water flows is both important for the future of the Everglades and symbolic of where we need to go as a civilization.

International borders can create another, often fatal, barrier on the land.  Ecosystems and wildlife don't understand immigration laws. So it was heartening this week to see the U.S. and Mexico formally recognize the transboundary ecosystem that comprises Big Bend National Park in the U.S. and the Rio Bravo del Norte complex in Mexico as a critical opportunity for binational ecosystem enhancement and protection.

If you want to understand why reconnecting the landscape is so important, and why we need to rethink  barriers like highways and borders so that ecosystems and human communities can adapt to a changing climate, look at this map of the natural-areas complex that sprawls across the Rio Grande River. The river is the heart of a single ecosystem, not a boundary between two -- just as the Tamiami Trail has been bisecting a single hydrologic entity (The Everglades) rather than marking a real boundary.