Christine MacDonald, an idealistic young environmentalist, discovered how deeply this cash had transformed these institutions when she started to work for Conservation International in 2006. She told me, "About a week or two after I started, I went to the big planning meeting of all the organization's media teams, and they started talking about this supposedly great new project they were running with BP. But I had read in the newspaper the day before that the EPA [Environmental Protection Agency] had condemned BP for running the most polluting plant in the whole country.... But nobody in that meeting, or anywhere else in the organization, wanted to talk about it. It was a taboo. You weren't supposed to ask if BP was really green. They were 'helping' us, and that was it."

She soon began to see--as she explains in her whistleblowing book Green Inc.--how this behavior has pervaded almost all the mainstream green organizations. They take money, and in turn they offer praise, even when the money comes from the companies causing environmental devastation. To take just one example, when it was revealed that many of IKEA's dining room sets were made from trees ripped from endangered forests, the World Wildlife Fund leapt to the company's defense, saying--wrongly--that IKEA "can never guarantee" this won't happen. Is it a coincidence that WWF is a "marketing partner" with IKEA, and takes cash from the company?

Likewise, the Sierra Club was approached in 2008 by the makers of Clorox bleach, who said that if the Club endorsed their new range of "green" household cleaners, they would give it a percentage of the sales. The Club's Corporate Accountability Committee said the deal created a blatant conflict of interest--but took it anyway. Executive director Carl Pope defended the move in an e-mail to members, in which he claimed that the organization had carried out a serious analysis of the cleaners to see if they were "truly superior." But it hadn't. The Club's Toxics Committee co-chair, Jessica Frohman, said, "We never approved the product line." Beyond asking a few questions, the committee had done nothing to confirm that the product line was greener than its competitors' or good for the environment in any way.

The green groups defend their behavior by saying they are improving the behavior of the corporations. But as these stories show, the pressure often flows the other way: the addiction to corporate cash has changed the green groups at their core. As MacDonald says, "Not only do the largest conservation groups take money from companies deeply implicated in environmental crimes; they have become something like satellite PR offices for the corporations that support them."

It has taken two decades for this corrupting relationship to become the norm among the big green organizations. Imagine this happening in any other sphere, and it becomes clear how surreal it is. It is as though Amnesty International's human rights reports came sponsored by a coalition of the Burmese junta, Dick Cheney and Robert Mugabe.