“It’s no longer enough to change our light bulbs. We need to change our culture.”

So says Erik Assadourian, senior researcher at the Worldwatch Institute and project director of a provocative and timely new book called 2010 State of the World: Transforming Cultures from Consumerism to Sustainability. Its argument is simple: The most important driver of the world’s ecological crises, including climate change, is not venal oil or coal companies or indifferent politicians but western consumer culture–that is, us.

Global consumption has grown dramatically since World War II, reaching $30.5 trillion in 2006, up sixfold since 1960. This is, in part, a very good thing–billions of people have emerged from poverty–but today’s prevailing consumption patterns are, quite simply, unsustainable. The rich (meaning you and me) are the worst offenders but ecologists say that even at income levels that we think of as substandard–say, $5,000 or $6,000 per person per year–people are consuming at rates that will deplete the earth’s resources, cause catastrophic climate change, wipe our species and generally trash the only planet we have.  About a third of the world’s people live above this standard, and the others, presumably, aspire to do the same.

This is not a message that either business or mainstream environmental groups want you to hear, which is why you don’t hear it often. Most businesses, though not all of then, are in the business of persuading people to consume more. They shaped the consumer culture. And enviros have found that telling their members and donors to buy less stuff is a downer, and not an effective fund-raising message, especially among the well-to-do.

But, as Assadourian said during a conference call with reporters, consumer culture is not only causing environmental havoc, it’s often failing to deliver the well-being that it promises.

Most people understand–and psychological studies of happiness confirm–that after we have achieved basic economic security (itself a cultural norm), what really makes us happy are close relationships, meaningful work, connections to community and good health.

You can’t buy those things at the mall.

“Two centuries of intentional cultivation of consumerism  has led to us seeing it as perfectly natural to define ourselves primarily by what and how much we  consume,” he said. Consumerism is so embedded in our culture today that, most of the time, it’s as invisible as the air we breathe.

Here’s how Assadourian explained the oft-hidden impact of culture on our lives:

The fact that we see it as normal to be able to identify hundreds of brand logos and jingles, while few of us can identify more than a few species of wild plants and animals—that’s culture.

The fact that we feed our children diets high in sugars, fats, and processed ingredients, even when we know this is making them fat and sick–That’s culture.

The fact that when loved ones die a ritual intended to lay them to rest requires injecting them with toxic chemicals and sealing their bodies up in expensive and ecologically costly caskets—that’s culture.

And the fact that we spend thousands of dollars each year on pets that we now see as part of the family, buying them food, toys, even health care that’s better than many people in the world can afford—that’s culture.

It’s all true, if mildly depressing. The Independent newspaper quoted one critic who said people need to be persuaded of the benefits of tackling climate change, rather than be presented with a “defeatist and doomsday scenario.”

So how do we get from here to where we need to go? “The good news,” Assadourian went on, “is that we can replace our consumer culture with a culture of sustainability.”

How, exactly, isn’t entirely clear. The Worldwatch book is a useful place to start–it includes contributions from about 50 writers and thinkers, including Muhammad Yunus, the 2006 Nobel laureaute, who wrote the foreward, and such cultural critics and analysts as Juliet Schor, Michael Shuman and John DeGraaf. Ray Anderson of Interface (who I blogged about here) co-authored a chapter on how business cultures can adapt to a culture of sustainability.

Actually, if you look around, it’s easy to see green shoots, albeit very small ones, that could grow into a culture of sustainability. The Great Recession has revived the virtues of thrift and frugality (although the just-concluded Christmas shopping season wasn’t bad at all.) Governments are created “choice architectures” to promote CFL bulbs and discourage plastic bags. School lunches are slowly getting healthier, at least in Britain, Rome and Grenoble, France, according to a chapter of the book titled Rethinking School Food: The Power of the Public Palate.

Religious leaders could, in theory, lead this cultural revolution and, in fact, some are stepping forward. A group called Interfaith Power & Light is organizing churches and synagogues to coordinate a religious response to global warming. As the Worldwatch Institute reported on its Transforming Cultures blog, Pope Benedict used his annual New Year’s addresses to talk about care for the environment, writing:

…the issue of environmental degradation challenges us to examine our life-style and the prevailing models of consumption and production, which are often unsustainable from a social, environmental and even economic point of view..

Who knows? If advertising and media sold us on the value of consumerism, maybe the same tools can be used to sell us on the value of a more sustainable culture. Jonah Sachs, creative director of Free Range Studies, who cowrote a chapter in the book called “From Selling Soap to Selling Sustainability: Social Marketing,” noted during the conference call that the tools of advertising are now low-cost and ubiquitous.

“People can find stories that appeal to them, share them with their friends and create explosive and cheap campaigns,” Sachs said. Social marketing, he writes, has helped discourage smoking, promote seat belt use and raise awareness about obesity. If  advertising and marketing helped create consumerism in just a few decades, social marketers could undermine it.

More to come on this topic, which deserves more attention. For now, if you haven’t seen it, check out the opening of activist Annie Leonard’s video The Story of Stuff, which was made by Free Range Studios and has been viewed by more than 7 million people and translated into 10 languages since it was released on the Internet a couple of years ago. You can find the rest here.