I've said before that just about all the people I meet in the plastics industry consider themselves environmentalists. And while that seems perfectly reasonable to everyone in the industry, it probably doesn't make sense to many outsiders who think of plastics as being environmentally harmful.

This column from AlterNet takes the issue one step further and asks, if big business is part of the "environmental movement," what does that mean for mainstream environmentalists?

Look at the evidence: General Electric Co.'s CEO wins a "Courage to Lead" award from the World Resources Institute; Home Depot introduces an Eco Options label for green products; General Motors and ConocoPhillips join a list of supporters for a mandatory ceiling on greenhouse gas emissions.

Is this good news for the environment? The columnist, Phil Mattera, research director of Good Jobs First, implies that it is not.

Today the term "greenwash" is rarely uttered, and differences in positions between corporate giants and mainstream environmental groups are increasingly difficult to discern. Everywhere one looks, enviros and executives have locked arms and are marching together to save the planet. Is this a cause for celebration or dismay?

Answering this question begins with the recognition that companies do not all enter the environmental fold in the same way. Here are some of their different paths:

Defeat. Some companies did not embrace green principles on their own--they were forced to do so after being successfully targeted by aggressive environmental campaigns. Home Depot abandoned the sale of lumber harvested in old-growth forests several years ago after being pummeled by groups such as Rainforest Action Network. Responding to similar campaign pressure, Boise Cascade also agreed to stop sourcing from endangered forests and J.P. Morgan Chase agreed to take environmental impacts into account in its international lending activities. Dell started taking computer recycling seriously only after it was pressed to do so by groups such as the Silicon Valley Toxics Coalition.

Diversion. It is apparent that Wal-Mart is using its newfound green consciousness as a means of diverting public attention away from its dismal record in other areas, especially the treatment of workers. In doing so, it hopes to peel environmentalists away from the broad anti-Wal-Mart movement. BP's emphasis on the environment was no doubt made more urgent by the need to repair an image damaged by allegations that a 2005 refinery fire in Texas that killed 15 people was the fault of management. To varying degrees, many other companies that have jumped on the green bandwagon have sins they want to public to forget.

Opportunism. There is so much hype these days about protecting the environment that many companies are going green simply to earn more green. There are some market moves, such as Toyota's push on hybrids, that also appear to have some environmental legitimacy. Yet there are also instances of sheer opportunism, such as the effort by Nuclear Energy Institute to depict nukes as an environmentally desirable alternative to fossil fuels. Not to mention surreal cases such as the decision by Britain's BAE Systems to develop environmentally friendly munitions, including low-toxin rockets and lead-free bullets.

In other words, the suggestion that the new business environmentalism flows simply from a heightened concern for the planet is far from the truth. Corporations always act in their own self-interest and one way or another are always seeking to maximize profits. It used to be that they had to hide that fact. Today they flaunt it, because there is a widespread notion that eco-friendly policies are totally consistent with cutting costs and fattening the bottom line.

I tend to give the corporations more credit. There are many cases where executives act in the interest of the larger community. Isn't it possible that environmentalism is so ingrained in our culture now that even -- shudder -- Wall Street executives consider themselves "green"?