Introduction

As Congress continues to shuffle its feet on climate change, other arms of the government are taking action.

In recent years the Pentagon has moved swiftly to debate how climate change affects U.S. national security policy — and how to meet the challenges of operating in what is literally a "new environment.”

As director of the Navy's 2009 task force on climate change, David Titley was at the center of those debates.

Originally a skeptic of climate change, Titley outlines how dealing with the consequences of climate change is rapidly reshaping the priorities of the U.S. military.

David Titley is a rear admiral, U.S. Navy – Retired, former chief oceanographer for the Navy and a fellow of the American Meteorological Society. The views expressed here are his own.

It's all about the water.

Okay, it's partly about food and energy, too. But from a national security perspective, climate change is all about the water: where it is or isn't, how much or how little there is, how quickly it changes from one state (e.g., solid ice to liquid water) to another.

Because of the effects of climate change in the Arctic, for the first time in 500 years we're opening a new ocean to navigation. The last guy who did that was Christopher Columbus.

Until 2005, the Arctic Polar ice cap consisted mostly of multi-year ice — ice that had formed two or more years before the date of measurement and was generally 2 to 4 meters (6.6 to 13 feet) thick and much harder to break through than first-year ice. Since 2007, most Arctic ice is now less than a year old and less than one meter thick. Climate scientists now expect that by 2030 much of the Arctic Ocean will be free of ice several months a year, opening it for commercial navigation just as the Baltic Sea is now.

The opening of the Arctic is the most immediate national security challenge presented by climate change. Except for submarines, the U.S. Navy has not operated widely on the surface of the Arctic Ocean; neither has anyone else. The Arctic is poorly charted and therefore dangerous to navigation. There's very little infrastructure and it's an extremely harsh operating environment.