Klein, whose new book, “This Changes Everything,” is the workbook for this new, more assertive, more powerful environmental movement (and the subtitle of which, “Capitalism vs. The Climate,” sums things up neatly), argues convincingly that “our economic system and our planetary system are now at war … there are policies that can lower emissions quickly, and successful models all over the world for doing so. The biggest problem is that we have governments that don’t believe in governing.”

If government believes that energy assets cannot possibly be stranded and capital must be allowed to pursue its interests no matter how harmful, there’s only one strategy for slowing the temperature rise that will eventually cripple the earth for 1,000 years. Unless you want to leave it to the very corporations that have a vested interest in maintaining the status quo and fighting change, which isn’t much of a strategy. Remember that Exxon Mobil remains in the world’s top three most profitable corporations. Why would it want anything to change?

No, the only choice is for people to fight climate change ourselves, by confronting the fossil fuel industry and fighting plutocracy. And while marches rarely change things immediately, they do demonstrate potential power. Sometimes, marches and associated activities — in recent times, most notably against the Vietnam War and for civil rights — have made a difference in moving history in the right direction.

Capitalism needs to expand in order to survive, Exxon Mobil is not going to willingly give up its stranded assets, and government will not force it to. And yet corporate sacrifice is in order. Chris Hayes convincingly compares the essential losses that fossil fuel companies face if we are to reduce the impact of climate change — somewhere between $10 and $20 trillion, according to his estimates — with the costs to slaveholders at the end of the Civil War. This was within government’s power, and can be again, but not this day.

That’s why so many centrists, liberals and progressives are depressed into inaction; they see no way of winning this struggle, no matter how critical. This defeatism, in turn, leads to Obama-style compromises in which the importance of working to limit the catastrophic effects of climate change are acknowledged but action is mostly limited to adaptation to those effects, adaptation that cannot possibly succeed in the long run without complementary mitigation. The fact is we must burn fewer fossil fuels.

We’ll continue to burn carbon short-term, but we don’t need the added risk of projects like the Tar Sands and fracking. Rather, we need policies that scale renewable energy sources up quickly. Klein cites the example of Germany, which reached a goal of making about 25 percent of its energy clean and renewable within 15 years, not through nuclear energy or massive hydroelectric projects but with bold national policies that systematically encouraged small players like municipalities and co-ops. (The parallels to agriculture are obvious, appealing, and relevant, but you can draw those conclusions yourself here.) “If,” says Klein, “you believe that because this is a big problem you need mega solutions — well, that’s not true. The most successful approach is decentralized and small, not, ‘me and my friends will start an energy co-op,’ but well-designed government policies that support small, clean, local energy generators.”

None of this will be easy, of course, but climate change provides us with an opportunity to remake our society in an image that comes closer to its rhetoric. “If we are to have any hope of making the kind of civilizational leap required of this fateful decade…” writes Klein, we need “a robust social movement [that will] demand (and create) political leadership that is not only committed to making polluters pay for a climate-ready public sphere, but willing to revive two lost arts: long-term public planning, and saying no to powerful corporations.”