Growing attention to the perils of global warming is increasing the pressure on nonprofit organizations such as universities, foundations, and even presidential campaigns to declare themselves carbon neutral.

In recent months, the drive to eliminate the “carbon footprint” created by the use of fossil fuels has broken out of the traditional environmental community. Among the latest to take the carbon-neutral plunge are one of America’s largest public broadcasters, KQED of San Francisco, the Academy Awards, and the White House bids of Senator Clinton and John Edwards.

The presidents of about 200 universities have signed onto a pledge requiring their schools to establish plans to work toward carbon neutrality, though most have committed to no specific date for attaining that goal. New York University, Syracuse, and Cornell are among the large New York schools on board. Besides Cornell, the only other Ivy League school to have signed on is the University of Pennsylvania.

So far, one American college has promised to achieve carbon neutrality immediately, the College of the Atlantic, in Bar Harbor, Maine. Oberlin College in Ohio has announced plans to do so by 2020.

To make good on their pledges, many institutions are turning to carbon offsets, which involve brokers who pay others to reduce carbon emissions, to establish renewable energy projects such as wind and solar, or to capture carbon by planting new forests.

However, the value and efficacy of these offset schemes is being “hotly debated,” according to the director of the environmental center at the University of Colorado at Boulder, Dave Newport.

“I’d rather spend the next few years figuring out how to do it so that it’s real,” Mr. Newport said. “That is not a sustainable solution. … That is not the end game.”

A prominent environmentalist, George Monbiot, has dismissed carbon offsets as “pernicious and destructive nonsense.”

“You can now buy complacency, political apathy and self-satisfaction. But you cannot buy the survival of the planet,” he warned last year in a column in a British newspaper, the Guardian.

Mr. Newport sees some value in offsets and credits as a way to promote renewable energy. He said his campus offsets about 10% of its energy use at a cost of about $70,000 a year. Rather than spend $700,000 for full neutrality, Mr. Newport said he advocates greater long-term efforts to conserve through technology and building design. “The offset should actually be the last step,” he said. “Efficiency is the best investment there is. The Wall Street Journal says that even the suits like it.”

So far, the sums most nonprofits are plowing into carbon offsets are modest. The San Francisco broadcaster, KQED, paid about $10,000 to cover its energy use and held a fund-raiser over the weekend to recoup the cost. An international charity supporting microfinance in the developing world, the Grameen Foundation, said it paid $11,067 to offset 4 million miles of air travel by its staff and volunteers last year.

A Harvard researcher on the nonprofit sector, Marion Fremont-Smith, said those expenses could be justified on fund-raising grounds alone. “People might withhold contributions if they felt the charity wasn’t paying attention to this,” she said.

However, as the trend spreads to large operations such as hospitals and to transportation-intensive efforts like meals-on-wheels programs, the trade-offs to gain the climate-friendly label are likely to become more stark. “Ten thousand dollars is a no-brainer. If it was millions or even a couple of hundred thousand, and it would mean giving up programs, the case would be much, much harder and you’d have to think twice,” Ms. Fremont-Smith said. “It’s always been an interesting question as to how far you can go away from your mission.”

“We think it’s part of our job to be a good citizen,” the head of marketing and communications for KQED, Donald Derheim, said. “We think that when you pollute you’re really cheating.”

NYU announced last fall that it was reducing its carbon footprint by purchasing 118 million kilowatt-hours of wind-generated energy, an amount equal to the school’s use of Consolidated Edison power in a year. This catapulted NYU to the no. 1 spot on a federal government list of universities purchasing “green power.”

However, Mr. Newport said the University of Colorado, which jumped into wind power five years ago, is planning to phase out its purchases of wind energy. “It’s time to move on,” he said.

The wind business is growing quickly and therefore has less need for stimulus, Mr. Newport said. He also said the potential for wind power to decrease overall carbon emissions is disputed because it often displaces natural gas-based energy, rather than coal-based plants, which are more polluting.