Al Gore. Photo: Lukas Schulze/Getty Images,

It would probably have been tempting, talking to Al Gore at any point over the 18 years — after 9/11, in the lead-up to the invasion of Iraq, in the depths of the financial crisis, as Obama failed to pass climate legislation and pushed the Clean Power Plan instead — to wonder what might have been. And what it must be like to be him, and, looking out at the world, wonder the same.

But the presidency of Donald Trump — which happens to coincide with a kind of “crisis” for the internet, one of his signature subjects, and a growing public appreciation for the planetary peril of global warming, his other — is an especially glaring prompt. And Trump does seem to be very much on Gore’s mind, too; he brought him up three separate times when I sat down with him last week, in New York, just ahead of his annual, 24 Hours of Reality special television event — an around-the-clock and around-the-globe climate change program which begins tonight at 9 p.m. This year’s broadcast, based in California, is focused on public health — which is all of a sudden a bigger and bigger part of the way scientists and climate advocates are talking about the threat from warming.

It’s interesting to talk about the California fires in this context, since one of the underappreciated aspects of that is the public health element.

For most of the week, the four most polluted cities in the world were Sacramento, San Francisco, San Jose, and Chico, worse than any cities in India.

And when you know what Delhi looks like, that’s really bad.

Absolutely. And you covered it in a recent article: the cognitive impacts, the particulate pollution.

Five, ten years ago, public health wasn’t even such a big part of the way that people talk about climate. What changed?

I will confess to you that, like anyone who works on the climate crisis, I have more than a few periods when I struggle with the difference between hope and despair.

The health consequences turn out to be a very effective lever to move public opinion on climate.

I had an experience about two years ago when, just prior to the election of 2016, the Centers for Disease Control scheduled a major conference on climate and health in Atlanta. Do you know this story?

I don’t.

Before the election, they scheduled this major conference and they reached out and asked me to give the opening keynote, which was something I regarded as an honor. But when Trump won the election, the CDC apparently panicked and canceled the conference. They had had an unpleasant experience with Congress the year before when they had a conference on guns as a public-health issue. And the Congress cut $16, $17 million out of their budget, which corresponded with what they were spending on that issue. I think they were afraid they were gonna have a repeat of that.

It struck me as kind of a chicken move. So I called President Carter and asked if I could have his Carter Center for the day of the conference and he said sure. And I called Ted Turner and asked if he would underwrite it, and he said sure. And so then I called the people who were gonna be at the CDC conference, and they all said, yeah, we’ll come anyway. And then the CDC experts took personal leave to come over.

That was an opportunity for me to dig more deeply into dimensions of this nexus that I had not spent as much time on previously. And the more I looked, the more shocked I was at how pervasive the health effects are. When the Obama White House, in President Obama’s second term, got in gear on climate and particularly when they introduced the Clean Power Plan, they had, obviously, done a lot of polling and political analyses and had decided to put the health consequences as their lead item. And, I thought, yeah, that makes sense.

I guess in the past, I have been so focused, and still am, so focused on the global existential crisis that just teasing out one part of it seems like a bow to the political polling reality. But, look, why not? Let’s engage people however we can do so most effectively.

Yeah, it seems to me that, so often, when people hear about it as a global crisis, they almost think, well, it’s happening elsewhere, I can avoid it. And something about health really feels immediate, like it’s going to affect your lungs, your mother’s lungs, your children …

And the health consequences are, of course, pervasive.

I mean, the numbers are staggering. It’s deaths every year in the millions from air pollution and …

Nine million is now kind of a baseline. It’s probably higher than that. You hear the phrase, now, air pollution is the new smoking.

I’ve been thinking about it in terms of lead. We now see all of these interesting consequences of the lead pollution in the mid-century. Every year there’s more stuff about criminality and mental illness. And it sort of seems a similar thing with air pollution. It’ll affect anybody with respiratory illness — okay. But there are also all of these more surprising effects — on schizophrenia, on autism. It almost seems like there’s nothing you might worry about that it doesn’t impact negatively.

And lead is the other pervasive, long-lasting pollution besides CO2. And the difference is, it can’t really be removed. Are we going to acquiesce in creating a reality where, from now until the end of time, we have to warn pregnant women and women of childbearing years that they can’t eat fish? And that they have to really be scared to eat fish? Really? Are we gonna create that permanent reality for all future generations? Apparently, we’re on track to do that.

We have taken some steps, but the biggest single source is burning coal, and so it’s yet another horror linked with this dirty fuel source.

One thing that strikes me as different about air pollution is there is this sort of grotesque trade-off with climate. There are these studies that show that the existing aerosol pollution is suppressing global temperatures by maybe as much as half a degree.

Yeah, I don’t really see that as being as much of a dilemma. It’s a co-pollutant. You get rid of CO2, you’re going to get rid of most of the aerosol pollution anyway, and we might as well face the reality of what we’re doing instead of masking it to a slight degree with the pollution. If the choice is more air pollution in order to get a slight dampening of the otherwise rapidly increasing temperatures, I don’t see that as a dilemma.

Well, I mean, ideally, we’ll take care of it all.

Right.

So, pulling back … When we last talked, it was right as you were launching Inconvenient Sequel, and, as always, you were pretty optimistic about solving this problem.

Yeah.

I wondered how that may have changed over the last year. The IPCC report on 1.5 degrees was obviously a kind of dramatic change to the way that people who are only casually engaged in climate think about the issue. But there’s also been, as you know, a series of dramatic, scary studies about what’s happening …

Yeah, and the fires, and Hurricane Florence and Hurricane Michael and Hurricane Harvey, and super-typhoon Mangkhut, and the all-time temperature records in …

All around the world.

More than 100 cities!

Yeah.

Cape Town running out of water — the list goes on.

Well, first of all, in the last conversation we had on this topic, I tried to exercise some caution in saying that my optimism is premised on the assumption that we will be able to awaken sufficient political will to accelerate the changes that have now begun in technology and business and policy changes that will speed up this transition.

I will confess to you that, like anyone who works on the climate crisis, I have more than a few periods when I struggle with the difference between hope and despair. It’s only natural, and the reports out in the last day or two, that the U.S. and the E.U. may now no longer be on track to meet their Paris goals is discouraging.

We went for three years with no increase in global emissions, but last year there was an uptick of 1.4 percent, and it looks as if we may see an uptick again for the second year in a row, China is building more coal plants, China and Japan are continuing to finance the building of a lot more coal plants in Southeast Asia and elsewhere. The fact that the Trump administration has taken all the retrograde steps that they’ve taken, that adds to the feelings of discouragement that anybody can be vulnerable to in dealing with this issue.

I refuse to believe, in other words, that we as human beings are somehow destined, by our nature, to destroy ourselves.

At the same time, the momentum for change in technology, in business, in investment, in regional government, state government, local government — that momentum is accelerating, for sure. Ireland just announced it will be the first country to totally divest from fossil fuels. I met three weeks ago with Yngve Slyngstad, who runs the Norwegian Sovereign Wealth Fund in Oslo. They’ve proposed 100 percent divestment of all oil and gas assets, and, of course, 100 percent of their wealth came from …

Yeah.

… the North Sea fossil reserves.

I could give you plenty of other examples. In California, the zero carbon by 2045 is a very dramatic move and very consequential. As you know, California, were it a nation, would be the fifth-largest economy in the world. Colorado, with Polis just being elected, they’re doing that by 2040. India has announced that by 2030 — 12 years from now — no more internal-combustion engine vehicles can be sold. I hope they follow through. There are now, I think, a dozen countries that have legislated the phaseout of internal-combustion engines.

So, in the electricity generation sector and the transportation sector, we have a clear and viable pathway to convert from impressive progress to exponential change. That still leaves manufacturing, steel, and concrete.

Agriculture.

Forestry, and building retrofits — the built environment. There are pathways open in all of the relevant sectors. But the progress in electricity generation is most impressive. Now, EVs are following quickly. These others are now beginning, but, to repeat myself, my assumption that we will summon the requisite political will to really accelerate these changes is the basis for my optimism.

I simply refuse to believe that the combination of an opposable thumb and a neocortex is not a viable combination on this planet. I refuse to believe, in other words, that we as human beings are somehow destined, by our nature, to destroy ourselves. I just refuse to believe it, and I’ve seen, many times, even in my lifetime, where seemingly impossible obstacles give way.

I often quote the late economist Rudi Dornbusch, that things take longer to happen than you think they will, but then they happen much faster than you thought they could.

But are there times when I wonder if that’s a reasonable and valid prediction of our future? Yes, there are such times.

When you see the IPCC suggesting that we need to halve global emissions by 2030, does that seem like an achievable goal to you?

It does.

With the help of carbon capture and that kind of thing or just on the basis of these rates of change that you’re talking about in all these sectors?

I don’t premise my hopefulness on the emergence of a miraculous technological breakthrough. We have all of the technologies and tools we need right now.

Will there be a breakthrough in carbon capture, pulling CO2 out of the atmosphere? I certainly hope so. By the way, the IPCC projections, not for the 50 percent goal but for the goal later in the century, they tell us we have to do that. Whether it’s through the so-called BECCS Program or in some other way, we probably will have to do that.

That’s a daunting challenge for sure, but it’s possible. It’s possible.

When you look at existing technologies, what are the areas that most excite you? Where do you think that there’s the most … I think we know electricity generation and those areas are moving very quickly. In the other baskets, what are the things that you think could most quickly make the biggest difference?

We are in dire need of changing common agricultural practices anyway, because we’re depleting topsoils at an unsustainable rate. We can’t continue with this Roundup fiasco.

It’s in our Quaker Oats. There’s Roundup in our oatmeal.

It’s in our Quaker Oats, and may be implicated in this so-called Insect Armageddon. You saw that article?

Of course.

I think that energy storage is about to undergo a truly dramatic transformation. There are new battery chemistries coming out almost every month now.

You may have seen recently in Illinois one of their largest utilities just submitted their plan for the future. They said it’s cheaper to shut down all of our coal plants long before their useful lifetime is exceeded and replace them with wind and solar.

The coal industry in Illinois, which is substantial, they don’t call it Carbondale for nothing, objected and said, “No, you didn’t use this assumption, that assumption.” They went back, “Okay, we’ll put your assumptions in.” The result was exactly the same.

It seems like there’s been a global — slow, I guess, but global — realization: We used to think that there was an economic trade-off to climate action. But, the more that we learn, the more we study, it’s just economic payoff after economic payoff. We save so much by moving more quickly.

Win-win-win. And the more the cost gap grows, and the more attractive the transition to renewables is, the more inevitable it becomes.

So I do take a lot of hope from the speed with which these changes are taking place. The missing element is political will. But, there’s another new element here. Mother Nature is …

Waking people up.

At the same time, Donald J. Trump is now the face of climate denial. His is the voice of climate denial.

The two-thirds and more of the American people that have had enough of Donald J. Trump are hearing and seeing him spout climate denial in his own uniquely offensive manner. I think that’s triggering the well-known law of physics, for every action there’s an equal and opposite reaction.