Bill McKibben and I are old friends.
It started in 2012 when I read his wonderful Rolling Stone piece clarifying the climate emergency. I called him up and asked him to talk.
We’ve been friends – and often, collaborators – ever since. And while our careers have often taken different paths, we’ve both been oriented toward the same fundamental goal: Fighting the climate emergency the best ways we each know how.
Ahead of Climate Week NYC and Sun Day, Bill and I sat down to continue the conversation we started in 2012. We discussed the state of the climate emergency, the environmental movement, and the economic and geopolitical realities that are reshaping the climate future.
We have the technology and the solutions to scale up and accelerate clean energy, making it cheaper, better, and faster for all. Now, we need to execute.
Watch the video or read our conversation below.
This transcript has been condensed and lightly edited for clarity.
Tom Steyer: Before we get going on the substance, maybe we should tell people the story of how we met.
Bill McKibben: You cold called me and said you wanted to talk about climate change. I knew nothing about you except that you are a well-heeled investor – a class that I normally do my best to avoid. When you insisted, I said, in that case we'll go for a hike thinking that at the very least I'd get a hike out of it. We went into the high peaks of the Adirondacks and began a fascinating conversation that we've been carrying on until this day.
Tom Steyer: From a climate standpoint, in September of 2025, where do you think we are?
Bill McKibben: We're in a terrible place. The warnings that I started issuing in the 1980s when I wrote The End of Nature, sadly are coming true and coming true truthfully a little harder and faster than we would've guessed. We now see just the daily toll of fire and flood, so insistent and continual now that we sort of forget about them. Sections of America's second biggest city burned to the ground in January and it's as if we've sort of forgotten. But now we're also seeing very systemic damage to the way that the earth operates. Were it not for the ongoing and very rapid demise of our democracy, the demise of our planet would be the thing that would be waking me up at 3:00 AM every day.
Tom Steyer: You've been a critical part and a leading member of the environmental movement. The End of Nature was really a call to arms around the natural world and making sure we had a safe and healthy natural world. In 2025, one of the voices that I perceive as being much more muted than it's ever been in my lifetime has been the environmental movement at a time when the need for that voice is higher than ever. How do you explain that and what do you think is the impact and the solution?
Bill McKibben: The climate movement, in a lot of ways, won the victories that it had been working towards under Joe Biden. The passage of the IRA really was the culmination in certain ways of lots of work by lots of people, especially young people, the Sunrise Movement, over many years. Then to watch it all just get flushed away in the first months of Trumpism, I think people don't know quite where to turn or what to do next. But happily we're seeing people at least recognize that one path forward that we now have is this abundance of cheap, clean energy. The first 35 years of the climate movement were spent in a world where fossil fuel was cheap and renewable energy was expensive. Now, as of the last few years, we live in a mirror world where renewable energy is cheap, fossil energy is relatively expensive, and so in a sense, the shoe is on the other foot.
Tom Steyer: Of course the lines have crossed in terms of costs, but the other thing that is true because all economics is dynamic, not static, is that we have fossil fuel prices over a hundred years adjusted for inflation that are flat and we have renewable, which means manufactured, human made energy, which has gone down 90% plus and will go down another 90% plus. So it's not just that they're cheaper, it's that the trajectories are completely different.
Bill McKibben: We built this world on relatively cheap fossil fuel, but this stuff that we've got now is cheap in a different way. Every time we build twice as much of it, the price drops in half. That's the kind of change that reshapes worlds pretty quickly.
Tom Steyer: And the world is being reshaped. One of the things that people felt was, if we win in the marketplace, we will win. We'll see emissions go down dramatically in the 2020s and that is the first major step to getting this whole situation under control. We're seeing all of the adoptions that normal economic theory says when a new dominant disruptive technology comes in. What we're also seeing is that we're not retiring the old technology because we aren't building the new tech. It's not replacing, it's augmenting. And that's why we've seen really no drop in emissions in the 2020s.
Bill McKibben: We're beginning to see, in particular places, huge drops. California is using 40% less natural gas to produce electricity this summer than they were two years ago, and California is the fourth largest economy in the world. The Chinese seem to have peaked their emissions now, CO2 emissions and fossil fuel use are down finally this year, despite the fact that their economy continues to expand at a rapid rate. If it were not for the press of climate change, then we could just sit back and happily watch this thing play out. The problem is that we have to move fast because we're going to run the world on sun and wind in 30 years. It's that cheap. But if it takes us anything like 30 years to get there, then the world we run on sun and wind is a broken world. So that's what we have to avoid.
Tom Steyer: In California over the past couple of months, there have been a series of measures to try to stop letting perfect be the enemy of the good to try to adjust processes and regulations to make them more user-friendly so that we actually can get things done so we can build things and deliver the outcomes we need to deliver. Knowing that nothing is perfect.
Bill McKibben: I think one of the more important next steps of this is at the state and especially the local level – there's a ton of work to be done on rooftop solar. And it's blocked mostly by dumb municipal codes. Every city has its own building code. They all have their own team of inspectors. That's why it costs three or four times as much to do this as it does in Australia or the E.U. That's one of the places, even with the federal government in strange hands, where we can do some work.
Tom Steyer: In the developing world, people are just buying solar panels. There's no utility involved, there's no government involved. There's just cheap solar panels. In the developed world with the time delays and the cost of regulation and all the issues with the grid. You have to use the existing footprint. If there's a roof, we don't need to build a roof. You don't have to get a permit for a roof because you have a roof. That is a critical fact when we think about this energy transition and about solar and wind and all the other new technologies that are cheaper, faster, better.
Bill McKibben I've lived on rural dirt roads all my whole life, some in red states, some in blue. I have lots of neighbors with Trump flags and a fair number of them have solar panels on their roof. And the reason is ‘my home is my castle’ and I like having an independent power supply to it. And truthfully, I feel that way too in my house. That's not why I put up those solar panels a quarter century ago, I did it because I care about climate change, but I also understand that feeling. I think it helps explain why, for instance, Texas is now the leading solar installer in the country.
Here's a really good one: You know this balcony solar stuff that started in Europe, three or four million Europeans. You just plunk down a few hundred euros, you get yourself a solar panel, you hang off your balcony railing, 20%-25% of your power being generated just with a standard plug into the wall. Illegal everywhere in the U.S. except the progressive bastion of Utah, which the state legislature two months ago unanimously said, ‘We're enabling this because if it's good enough for the people of Stuttgart, it should be good enough for the people of Provo.’ We need to be able to work across some of those lines.
Tom Steyer: We do think of California as the place that's trying its hardest on a continuous basis to be on that edge of being interesting. As somebody who invests in companies that are trying to solve the climate problem and encourage the energy transition, let me say we are seeing amazing young entrepreneurs. We are seeing amazing progress. We are seeing real, measurable success.
Bill McKibben: Doesn't it piss you off that we're now ceding most of that business off to China, like the core parts of the technological future?
Tom Steyer: The traditional framework for new ideas to go global at this point is American technology, American entrepreneurship, Chinese mass production, Chinese deployment.
Bill McKibben: That's now flipped. 75% of the patents in the clean energy space in the last 10 years, including most of the high quality ones, have been coming out of China.
Tom Steyer: This is a global challenge. The thing is I think we should definitely be saying to an overwhelmingly American audience is that there has been and continues to be a huge global response to climate. It continues. I've traveled around the world in 2025 talking to people from different continents, different cultures. They have all been committed to the awareness of climate, not denying climate, anxious to participate in the solution, anxious to make money from the solution.
Bill McKibben: There's only one country that's pulled out of the Paris Climate Accords. It just happens to be the country that put the most carbon into the air.
Tom Steyer: Policy matters. My daughter, her husband, parents-in-law, and our less than 1-year-old grandson went out to look at whales in New York Harbor. They sent me the pictures. And there are humpback whales breaching in New York Harbor. Why is that true? Well, the world passed a no whale hunting policy decades ago and all of a sudden there are whales. There's a look of wonder on that little boy's face that's just priceless. The point being, yes, policy matters. Yes, in order to drive deployment you have to have profits and you have to have capitalism and private enterprise and all that, all of which I believe in. But the framework that that takes place in is really, really important.
Bill McKibben: Clearly for the moment the Chinese have figured out the policy framework to drive this stuff forward. Probably as important, their trade links across the developing world seem to be the avenue by which this is going to spread fast. The story that I like best from last year is the story about Pakistan. Pakistanis, not the government, build the equivalent of half their national electric grid last year just with solar panels. And all they're doing is looking at TikTok videos about how to snap them together. And all of a sudden that's what energy in Pakistan is.
Tom Steyer: You wrote a book, Here Comes the Sun, about the solar revolution, the continuing explosion of solar technology globally, which you're referring to in Pakistan. From my standpoint, that is just a classic disruptive technology. Who still has a black and white TV? Nobody watches a black and white TV because once it changes, Cheaper, Faster, Better – it's over.
Bill McKibben: One of the very funny stories of all of this is that BYD, the biggest Chinese automaker, has plans for a big plant in Mexico near the border, but apparently they're having second thoughts. They're worried that their technology will leak across the border to America. Our notion that Detroit is central to the auto industry is, I'm afraid, wrong now. There's three or four cities in China that are producing better, cheaper cars.
Tom Steyer: There is an obvious comparison which is phones. Most of the world, the developing world certainly, never will build landlines. And you probably haven't used a landline in a really long time, and neither has anyone else because we just use cell phones. The energy technology for the developing world will never go there.
Bill McKibben: Our job I think is not to figure out exactly where it all goes just to help. We've both got grandkids, which means we both have people that we know and love who will be alive in the 22nd century. We've got to figure out some minimum way that we can make that century a livable one. That means short circuiting climate change at its worst as fast as we can.
Tom Steyer: When you think about that, and my first question to you, because you know so much about it and have followed it so intimately for such a long time, was where do you think we are? And you said, basically, we're on the bad projection that I would've made 35 years ago.
Bill McKibben: But we now have for the first time a tool that scales to start getting at that clean energy. Will it stop global warming? Obviously not. Might it stop it short of the place where we cut civilization off at the knees? Maybe. Certainly we're capable of trimming some tenths of a degree Celsius off how hot the world gets. And at this point, every 10th of a degree that we raise the temperature moves another hundred million of our brothers and sisters out of a safe climate zone and into a dangerous one. So that's important work.
Tom Steyer: There's something we haven't talked about that I personally think can be very significant and in reasonably short order if we're willing to get behind it and that's sequestration. What we see from our work in looking at the natural world sequestration, which I know many people have felt that the early stages of that didn't deliver in a measurable way what they promised. But what we're seeing is technological changes to both sequester and to measure reliably that sequestration at the gigaton level.
Bill McKibben: At the moment, the thing that most people have an ability to get behind and make happen in short order is the acceleration of this energy transformation because that acceleration really depends on public participation. Above all, getting people just to realize that it's no longer alternative energy, it's now the way we do this. So that's why we're doing Sun Day on the 21st. I happen to know that beneath your well buttoned up shirt, you too are wearing the Sun Day logo.
Tom Steyer: I certainly am.
Bill McKibben: You've been a part in making this happen. Hundreds of events across America that are all designed to drive home that message.
Tom Steyer: Let me ask about that. The thesis of my book is, the reason people in Pakistan are doing this, is because it's a good deal. Some combination of innovation, policy, and driving costs down means the cost curves have crossed. I think we should be pushing it as hard as possible. It’s basically saying you should do this because it’s a great deal for you.
Bill McKibben: That's very true and that is the reason that it's happening in lots and lots of places. But it's also true, as you know from when you ran for president, that people have complicated motives in the world. And that part of the job too is to summon that side of us that really wants to play a positive role in the future of the planet.
Tom Steyer: I don't want to play down the attention economy: the national conversation, the global conversation. In the places in the world where people are accustomed to adopting new ideas – take Silicon Valley as a place that's all about new ideas and innovation – a typical innovation is adopted by its customers in 18 months. In the utility business, which is all about making sure you deliver energy reliably and don't take chances because you can't afford to take chances. 35 years. We have to do this in a timely fashion. If people are convinced this is a realistic, smart, dependable thing to do, we move towards the 18 months. And if they think this is a really risky, expensive, difficult thing to accomplish, we move the other way.
Bill McKibben: Absolutely. Pace really is going to be what matters. We're now in a race. The numbers were really interesting. You'll remember, because we were talking about it at the time, June 2023. It's the first month when scientists say the temperature is now spiking again. These are the hottest temperatures we've seen in 125,000 years on this planet. June 2023 was also the month, as best we can tell, when humans started installing a gigawatt worth of solar a day around the world.
Tom Steyer: Response is happening as the need is greatest.
Bill McKibben: It's exactly the same time. God knows if we can catch up, but it is the one place where we're making real progress.
Tom Steyer: Bill, it's really nice to see you.
Bill McKibben: Such a pleasure, brother.
