Ruth Petkaitis teaches music to kindergartners in Hartford, Conn. Photo by Christopher Capozziello/Education Week.

There aren’t enough young people in the pipeline to fill the estimated 2.9 million to 5.1 million more teachers who will be needed by 2020. That means school districts will have to embrace career-changers, who, as it happens, are also embracing teaching.

“Tapping the potential of mid-career professionals and older adults seeking ‘encore careers’ isn’t easy,” reports The Christian Science Monitor. “But education policymakers increasingly see it as essential.”

The good news is that a surprising 42 percent of college-educated adults ages 24 to 60 would consider teaching as a career, according to a survey by the Woodrow Wilson National Fellowship Foundation in Princeton, N.J.

The respondent expressed particular interest in teaching in areas where there are teacher shortages, such as science, technology and math, and 30 percent of them said they would find it appealing to work with children from disadvantaged backgrounds or in a low-performing school.

Prospective teachers are concerned, however, about low pay and the time and trouble it takes for midcareer professionals to become certified teachers.

School districts “won’t be able to replace half their workforce unless they change the structure … to embrace these career-changers,” Tom Carroll, president of the National Commission on Teaching and America’s Future, a research and advocacy nonprofit in Washington, told the Monitor. He said what is needed is a more collaborative work environments and a pay structure that credits experience in other fields and rewards job performance.

Joel I. Klein, chancellor of New York City Schools, suggests front-loading teacher salaries and offering bonuses to the highest performers. He pointed out that much of teacher compensation goes into defined-benefit pension plans that older teachers have less time to accrue.

The Woodrow Wilson report found the average starting salary for teachers in the U.S. is under $40,000. If starting salaries were higher, more people would be attracted to teaching.

More programs like Connecticut’s Alternate Route to Teacher Certification that make it easier for career switchers to transition to teaching, would also encourage more to make the change. The Pentagon’s Troops to Teachers program helps veterans make the transition to teaching with subsidies and bonuses.

Large majorities of the potential teachers said it is extremely important that their job be personally rewarding, contribute to society and make a difference. Those findings echoed the sentiments found in a recent MetLife/Civic Ventures Encore Career Survey. That survey found that about 8 percent of Americans ages 44 to 70 are already in their encore careers and 50 percent of the others surveyed said they want to use their talents to improve society by working in fields such as education, public service, health care and the nonprofit sector.