Bill McKibben is an author, environmentalist and founder of 350.org. (KK Ottesen/For The Washington Post)

Bill McKibben, 58, is an author, environmentalist and founder of 350.org, a global grass-roots climate change movement. He spearheaded the fossil fuel divestment movement and resistance to the Keystone oil pipeline. His latest book, “Falter,” will be released in April.

What drew you to environmental issues first, and can you talk about your progression from writing to full-fledged activism?

My first job out of college was at the New Yorker. And I wrote my first long piece about where everything in my apartment came from. You know, Con Ed was getting oil from Brazil, so I went down to Brazil, and up to the Arctic [where] they were getting hydro power. Along the New York City water system, on garbage barges, in sewer systems and so on. Somehow, doing that reporting impressed on me not only the physical-ness of the planet, but the fact that these were somewhat vulnerable systems, more fragile than I had assumed. That set me reading the early science on climate change. And I wrote “The End of Nature,” the first book about this subject for a nonscientific audience.

I guess I thought that that was my contribution. And I kept writing about it. But, at a certain point, it became clear that writing another book was not going to move the needle on this, that what had started out as an argument no longer was. The argument was over. The science was entirely clear by the mid-1990s. But people like me — writers and academics — were still treating it as an argument because that’s what we knew how to do. You know, the answer to all questions is another symposium, another article, another book. It took a while to figure out that there was another side here — and that it was winning. And it was not arguing; it was fighting. The fossil fuel industry, which is the richest, most powerful industry in human history, having lost the argument was easily winning the fight. Because the fight was about money and power. So, on the theory that occasionally in history, movements have been able to compensate for a lack of money and political power, I thought we should try to build a movement. The problem with climate change as an issue, obviously, is it’s the first issue with a time limit that we’ve come up against. And so we felt very strongly the need to keep kind of upping the ante — so we moved from rallies and things into more direct confrontation with some speed.

As you found yourself in the position of successful activist, having led massive protests, did it change the way you thought about yourself?

It was a little weird. For me, the main problem is introversion. I mean, I got pretty good at giving a speech. But left to their druthers, writers are people who would like to sit in a room and type; it’s a strange affliction. For certain kinds of people, it’s just the opposite, you know? If you watch real politicians walk into a room, if they shake 100 hands, somehow a small quanta of energy goes from each hand into them. But with me, if I shake 100 hands, I’m pretty worn out, like: Time to go sit and read. So I’ve spent a lot of the last five years trying to put the spotlight on other people. And now, happily, there’s a ton of new activists. And they’re all younger and more interesting.

So, with science on your side and billions of people affected, why hasn’t there been more success?

We’ve understood more about that over the last few years [through] really great reporting about the fossil fuel industry. It turns out that they had all the science — and decided to mount an absolutely full-throttle effort to make sure that nobody came to understand what was going on. The amount of money, time and effort they invested in obfuscation and denial turns out to be staggering. And successful. They delayed, by a generation, action on this. Even at the cost of breaking the planet, which they fully understood was the cost.

So at this point, success is not stopping global warming. That’s not on the menu. Success is stopping global warming short of the point where we can’t have civilizations like we’re used to. We’ll continue to work very hard. But we’re not going to get out of this anywhere near unscathed. And the sad truth is that Mother Nature is a very powerful educator. Last fall, some combination of reports from the U.N., the ongoing idiocy of Trump, and those California wildfires combined to change something. And we’re at a moment — some kind of new inflection point. Let’s see what we can make of it.

This interview has been edited and condensed. Follow KK Ottesen on Twitter:  @kkOttesen .