David Wallace-Wells talks with Bill Gates about climate change today.

If we are imagining a world in which we take some dramatic action and engineer some kind of meaningful solution to this challenge, what does that look like to you? How big a part of it is nuclear power? How big a part of it is carbon capture? How big a part of it is new cement? How do you see that big picture?

There’s a long answer to that. I would like to help educate people on what a plan really means. A plan involves looking at all the sources, electricity, transport, industry, buildings, and land use/agriculture and really saying, “Okay, what are the possible paths that get you to these dramatic reductions, and therefore what are the missing inventions?”

Fortunately, there’s not any one path. If you don’t have nuclear and if you don’t have a storage miracle, it’s very, very hard, because basically what you have to do is have electricity be used for many, many, many things like all building heating and cooling that today, you use natural gas or coal for it directly….I have not seen anything that’s worthy of the word plan because a plan has to involve not just the U.S. doing something.

Of course, yeah.

You have to convince middle-income countries. I think of India as paradigmatic, because it’s big enough to count and it’s poor enough. They deserve to have air conditioning. I mean, they’re getting very high wet-bulb temperatures. Jesus Christ, by 2070, there could be just a massive number of people dropping dead in the streets.

So a plan that really addresses the global issue has to bring what I call the green premium for all of these various goods and services down dramatically, like over 90 percent.

What’s the green premium?

What would green cement cost today? What would green steel cost today? What would green beef cost today? It’s great that people care about the issue, but it’s a very complex issue. And, unfortunately once they hear about how hard it is to solve and how expensive it is to solve, I hope their resolve isn’t … When diesel prices got increased 15 percent in France, more near-term considerations came into play.

The international picture there is so important because each individual nation, with the possible exception of the U.S. and China, is contributing only so little….How do you define success in the climate story?

It’d be great if we could stop at two degrees. Unless there are huge surprises on scientific advances, I just don’t see it happening, but who would have said that [about] radio waves or wireless or chips with a billion transistors? We know Václav [Smil] is not optimistic. Yet to really get people engaged, you have to say, “Hey, we can really achieve this thing.” The fact that the R&D budgets weren’t even being discussed …

R&D does seem very important.

I mean, not to be egocentric, but that was put on to the Paris climate agenda because I went to France and said, “Hey, here’s something you get to do that’s going to be different.” Then it turned out that was the way of getting Modi to actually come to the thing, which was fantastic.