Leslie Gillespie’s career is in transition—again.

That’s typical of lots of professional women right now, especially those seeking sustainability opportunities (CLICK HERE to read Blog #1 on How Women Get Green Jobs).

Transitions–whether into and out of government, academia, nonprofits and the private sector, from corporations to start-ups or even within the same organization—appear to be a staple of forging a sustainability career. And the transitional “indirect path,” as Ms. Gillespie calls it, to a sustainability job seems to be the norm so far.

That career approach—transferring skills and knowledge from a range of past experience and education—is corroborated by the Heldrich Center for Workforce Development at Rutgers University in New Jersey, where Project Manager Laurie Harrington has been researching emerging skill requirements of a changing economy. “What’s most important is adaptability,” she said at the recent SustaiNext Summit in Philadelphia, where we were both speaking on trends in sustainability work and education.

Upping the ante on Ms. Gillespie’s current transition—from the White House to the US Army’s sustainability office—is the big announcement in late April that the Army has identified a number of locations as pilot ‘net zero installations,’ in an effort to consume only as much energy or water as produced, while eliminating solid waste to landfills.

When I first met her less than four years ago, Ms. Gillespie, a graduate of the US Military Academy at West Point, was working as a civilian for the Army, forging a sustainability initiative in a part of the federal government that presents both a sustainability challenge (big military installations and wars can create all kinds of environmental, social and economic challenges) and a unique set of solutions (the military has the technological know-how, the team spirit and the clout to help solve large-scale problems).

Since our initial meeting, Ms. Gillespie spent 18 months on assignment to the White House Council on Environmental Quality (CEQ), working for the Federal Environmental Executive to help implement the President’s Executive Order on Federal Sustainability (E.O. 13514) that calls for the Federal government’s leadership on a range of environmental, energy and economic performance measures, with a special focus establishing new guidance and measurable performance targets for greenhouse gas emissions across Federal agencies (CLICK HERE to read about CEQ’s Nancy Sutley and WNSF’s West Coast Summit).

Ms. Gillespie is now freshly returned to the Army as Director of Sustainability Policy, working for the Deputy Assistant Secretary of the Army for Energy and Sustainability.

“It’s kind of interesting right now, and also kind of the same, because I’m transitioning again—which is like everything in the past,” says Ms. Gillespie, who, after graduating from West Point in 1994, spent five years of active duty in the US and Korea as a readiness officer, left active duty as a Captain, went back to school for a master’s degree in civil engineering, then worked as a defense contractor supporting both the Army and the Navy, and returned to the Army as a civilian employee to manage environmental and sustainability policy, before starting at the White House, where she also began working simultaneously toward a Ph.D. in environmental and energy management.

Getting—or molding—a sustainability job is a continuous transition. “Sustainability is so enormously broad, that you need people with broad skills, so it’s all about acquiring different skills, learning how to apply them and translating them to different situations that allow you to bring something unique to what you’re doing,” Ms. Gillespie says.

“It’s about taking an opportunity without knowing what it will lead to, trying to shape it, acquiring new skills, figuring out what’s meaningful to you and making your experience work for you,” she adds.

As a general rule, broad skills and the ability to transfer them to new situations will be key to getting and managing jobs—green or otherwise—in the new economy, says Ms. Harrington of Rutgers. Increasingly, “workers have amorphous titles and duties, need stronger technical skills and wider general skills, as well as interdisciplinary knowledge and adaptability to managing new problems,” she says.

All of which sounds a lot like Ms. Gillespie’s recipe for a sustainability career—namely, the only constant is change.