New Mexico Mercury

It has long been said that topography doesn’t recognize border lines. Certainly, the transborder spread of the Sonoran and Chihuahuan Deserts cannot be denied. No matter how high nationalist fevers rise or how obstructive new border security infrastructure may be, the same deserts occupy both sides of the border.

Still, the border wall and fortified ports-of-entry tend to diminish consciousness about the shared environment. What is more, the border fortifications do obstruct traditional wildlife corridors -- making the border quite real, for the first time, for deer, mountain lions and antelopes, for example. Although border infrastructure may scar the cross-border landscape with roads and ditches, the topography on one side remains a close reflection of the other side. The border has a greater impact on water flows, as each border state and nation fights to channel and retain water, rather than allowing it to flow across state and national borders. Governance mechanisms such as the International Boundary and Water Commission and inter-state accords manage these conflicts and demands, thereby underscoring how political geography has altered the traditional patterns of transborder surface water flows.

New U.S. initiatives associated with immigration reform proposals aim to seal the U.S.-Mexico border with more hulking fences, high-tech surveillance, sensors, and drones -- all to “secure the border” against a dramatically diminishing flow (lowest in four decades) of south-north immigrants, and costing at least $30 billion in additional border security funding.

Generally unnoticed in this border security buildup is the rapid onset of a new transborder security threat. Not immigrants, not terrorists, not drugs, not spillover violence. Rather frightening changes in the deserts, in the mountain flora, in the surface water flows, in the falling levels of reservoirs, and in the disappearing aquifers and underground water basins.

This is not a south-north threat to security but one that shares common ground -- the vast transborder aridlands that include, on the U.S side, Colorado, New Mexico, West Texas, Arizona, Utah, Nevada, and southern California. On the Mexico side of the border, Durango, Chihuahua, western Coahuila, Sonora, Baja California Sur, and Baja California Norte face the same transborder threat.

Decades ago close observers presciently predicted (notably Marc Reisner in Cadillac Desert published in 1986 -- or more than a century before by explorer John Wesley Powell) that the region’s reckless development was not sustainable -- given limited and nonrenewable water resources. In large part, the water crises reverberating throughout the Transborder West were threatening the models of economic development and human settlement in the region prior to the ever-more apparent scourges of climate change.

Clearly, any thoughtful observer could see that Phoenix, Las Vegas, Tucson, Juárez, Hermosillo, Chihuahua City, and many other urban surges are not sustainable -- whether observed in 1980 or in 2013. These and other desert cities were not extensions of natural oases but artificial creations dependent for their survival on imported water and unsustainable exploitation of groundwater reserves.

Climate change has accelerated and compounded the looming threat of over-allocated water flows and rapidly depleting underground accumulation of largely fossil water. In the last couple of decades, drought cycles have become more intense and longer lasting. Rising temperatures linked to human-caused climate change also mean that accumulated water is evaporating more quickly and that the transpiration patterns developed by regional flora over the millennia no longer guarantee survival for ecosystems in prolonged periods of drought.