Environmentalism, like politics in general, is depressingly polarized these days. On one side, alarmists like the activist Bill McKibben, climatologist James Hansen and blogger Joe Romm warn that if we don't cut way back on fossil fuels—now!—civilization may collapse. On the other side, deniers, including most of the current GOP candidates for president, won't even accept a causal link between surging carbon emissions and warmer temperatures. (Newt Gingrich advocated countering global warming in 2007 but now, sucking up to conservatives, calls global warming an unproven "theory.")

Forced to choose, I'd go with the alarmists, who at least are guided by science and concern about humanity’s long-term future. But some greens, notably Romm, are so shrill and hyper-partisan that they harm their own cause. Just as many voters yearn for a third party that transcends the fractious old politics, so I and many other people are eager to hear fresh, creative approaches to global warming and other enviro-threats.

That's why I'm a fan of Ted Nordhaus (left in photo) and Michael Shellenberger, iconoclasts who run a think tank, the Breakthrough Institute, in Oakland, Calif. While most green—and anti-green—activists preach to the converted, Nordhaus and Shellenberger challenge basic environmental assumptions and values. Even if they don’t totally convince you, they should force you to reconsider your views on, for example, the debate over fracking.

In their 2004 essay "The Death of Environmentalism" and 2007 book Break Through: From the Death of Environmentalism to the Politics of Possibility (Houghton Mifflin Co.), they chastised greens for suggesting that perils such as global warming can only be addressed by curbing human progress. Economic development and technological innovation are essential, Nordhaus and Shellenberger argued, to help us overcome ecological crises.

I thought this message would resonate with faculty and students at the engineering school where I teach. And so in 2008 I brought Nordhaus and Shellenberger to my school to have a public conversation with Andy Revkin, then a New York Times reporter and now author of the influential Dot Earth blog. Later I chatted with Shellenberger on Bloggingheads.tv.

Now, I'm happy to report, Nordhaus and Shellenberger are back with an e-book, Love Your Monsters: Postenvironmentalism and the Anthropocene (Breakthrough Institute, 2011), in which they and other thinkers--including the French philosopher Bruno LaTour, whose riff on Frankenstein gives the book its name--re-envision environmentalism in upbeat terms. What I like best about the book is its optimism, which I'm coming to believe is a prerequisite for progress. What follows is my email interview with Michael and Ted about their new book.

John: Love Your Monsters makes the argument that the Anthropocene, the age of man, is something we should embrace. What do you mean by that?

Michael: What we mean is that don't have any choice. We are now the dominant ecological force on the planet and that means that we must ever more actively manage our environment. It is both a responsibility and an opportunity and it demands that we actually make hard choices. If we want more forests and more wild places, then we'll need more people living in cities and more intensive agriculture. If we want less global warming, then we'll need to replace fossil energy with clean energy, including a lot of nuclear energy. If we want to save places like the Amazon rainforest then we have to recognize that, over the next 50 years, a lot of the Amazon is going to be developed. The choices will come down to where we want development, and what we might save in the process.

John: In the introduction to Monsters, you say that environmentalism “has become an obstacle" to addressing global warming and other problems. What do you mean by that?

Ted: Environmentalists still imagine that solving those kinds of problems involves limiting the human footprint on the planet. But our footprint is everywhere. We are now, through our daily existence, modifying the environment on a planetary scale. The choices we face are not whether or not to modify the environment but how. We will exercise those choices through the ever more powerful social and technological tools and the enormous wealth and resources that we now have at our disposal. Environmentalism has long imagined that development, modernization and technology are the source of our problems, but they are now the only solutions. And, perhaps more to the point, there's no going back to the Holocene. Even if human civilization chose to it couldn't.

Michael: There is, but what's at stake isn't the survival of the human race but rather the quality of the global environment, our ecological inheritance and the costs—moral and financial—of environmental degradation. In many ways, Monsters is an effort to reconstruct a non-apocalyptic grounds for taking environmental action.

Michael: Absolutely. There is a new generation of environmentalists, and even some of the old guard has embraced this vision. We call them post-environmentalists in Monsters, folks like [Whole Earth Catalogue founder] Stewart Brand, [The God Species: How the Planet Can Survive the Age of Humans author] Mark Lynas, and [The Guardian newspaper columnist] George Monbiot, who recognize that because human development is inevitable, we're going to need lots of advanced technology, including nuclear, to reduce the risks of the Anthropocene.

John: How did you select contributors for Monsters?

Ted: After Break Through we discovered a much larger group of thinkers, mostly academics, some of whom knew each other and some of whom didn't, who were working on similar problems. A big part of the reason we started Breakthrough Journal is because we thought their ideas deserved a larger audience, and because we wanted to be in a situation where we could work with these thinkers to fully develop our arguments. Monsters was an opportunity for us to take some of the best thinking we've come across on the new ecological challenges we face and put it all together in one place.

John: How does Love Your Monsters build upon the themes of Break Through?

Michael: One of the ways is Break Through's critique of the concept of nature as a closed, fragile system in a state of delicate balance, and constantly at risk of tipping into chaos. In Break Through, we observed that there is a difference between a false choice and a hard choice. In Monsters, the authors all in one way or another further elaborate what those hard choices look like.

John: When you think about the future of the planet, what is your biggest fear?

Ted: My biggest fear is that outmoded, irrational and self-defeating ideologies about nature and the market will get in the way of humans making the shared investments in technological innovation required to be responsible earth stewards. I worry that slow rates of innovation among renewables and popular fears of nuclear energy will mean continuing high uses of fossil fuels for decades to come.

John: What is your biggest source of optimism?

Michael: I think my biggest source of optimism is the progress made by the human species. We are a far more intelligent and humane species than we were 100 years ago—not to mention 200,000 years ago! When I hear people worry that because humans evolved on the veldt we don't have it in us to manage large complicated systems, I think that's ridiculous. We never stopped evolving—physically, culturally and intellectually. At bottom, I think humans are more than up for the task of being responsible Earth stewards.