Increment: It feels like there was a narrative put into place decades ago that renewable or sustainable sources of energy were a pipe dream—that conservation wasn’t going to work.

Ramez Naam: For a long time, people in fossil fuels and people in the environmental movement or the deep green part of that, and even serious tech people like Bill Gates, thought renewables were toys—they thought there was just no possible way. And, in a way, you can’t blame them.

In the late 1970s, it cost $100 a watt for solar panel material, but the price has dropped 300-fold over the last 40 years. The first 100x price drop didn’t matter because solar was still more expensive than coal or gas. So all through that incredible price drop, people could say, “It’s a toy. It’s never going to make sense.”

In 1980, wind power was 10 times as expensive as good electricity in the U.S. Now, in the sunniest parts of the world, solar’s the cheapest energy, and in the windiest parts of the world, wind is the cheapest energy.

For somebody that comes from a tech background, we’re used to Moore’s Law: exponential improvement of price performance—of processors, memory, bandwidth. But in the energy industry, things just don’t happen like that. When you look at the price of solar or wind or batteries, there’s something like a much-slowed-down version of Moore’s Law operating. That means that as solar and wind and batteries grow in scale, the price just keeps coming down quite rapidly. Maybe we don’t know how to get to 100 percent clean electricity yet, but can we get to 70, 80, 90? Yes, one of those.

One of your most effective weapons is the IEA chart.

The IEA [International Energy Agency] made a first prediction of solar in 2002. They predicted that by the year 2030 the world would have deployed 50 gigawatts of solar. It’s not a meaningful amount: That’s 50 coal power plants’ worth of solar. China wanted to install that much [solar] by 2017, by itself. The world will be coming up on 400 gigawatts by mid-2018, in less than the time that the IEA forecasted we would get to 50.

Those forecasters are not used to energy being a variable technology that’s rapidly improving.

Because there’s a multi-decade or even longer period to recoup investment?

Yes. Over the long term, if you scale out to a century, the cost of energy has dropped. The cost of oil for the most part has slowly eked down, the cost of electricity at wholesale has slowly eked down—but nothing like the pace at which the cost of solar and wind and batteries have and are continuing to plunge. And that’s the most important part, really: The price decline of these new energy technologies isn’t over. We’re at an interim point.

There’s every reason to believe that solar will drop in price by about half again, wind power will drop in price by about half again, batteries might drop in price by about 5x to 10x again. And when you start talking about that, you [should] talk about them [prospectively] dominating in energy, not them being the only source of energy.

There are some obstacles in their way, though: The sun doesn’t always shine, and the wind doesn’t always blow. But we’re getting closer and closer to a solution, at least for a day-long cycle, as the cost of energy storage drops and so on. We still don’t know how to store up excess sunlight from the summer for the winter—that volume is beyond our [current] abilities.

The biggest obstacle, really, is sunk cost. Compare the costs of building a new coal plant to a new solar plant. In much of the world now, building a new solar plant is cheaper than building a new coal plant, and, if that’s not the case now, within five to 10 years it will be, in almost all of the world.

People have this idea that most of the cost of coal electricity is the cost of the coal. It’s not—it’s the capital cost of building the power plants.

China has long been one of the biggest points of concern in reducing greenhouse gas emissions because of their continued use of coal. Now they’re canceling plants where ground was broken. A study came out that 96 percent of people in China would favor a major shift away from coal.

If you ask anyone around the world which energy type they want—solar, wind, gas, coal—basically everybody says more solar, more wind, less coal. People also say less nuclear. But the place that is most extreme is China. China is where renewables are the most popular among the populus.

Climate change and smog are not the same thing. They’re like a Venn diagram, and where they overlap is coal and tailpipe emissions from dirty vehicles. [Many] people in China live in this oppressive smog. They cough, they wear masks, they can’t see 20 feet in front of them some days, they know their kids are growing up in this, they know their government is lying to them about the health effects, and they want it to change.

Pollution, broadly, is the number one source of unrest and citizen dissatisfaction, and it’s actually an essential threat to the rule of the Chinese Communist Party because they have to do something about it to keep their people content.

Is China trying to take on some moral authority associated with energy and climate change?

Yes and no. China is playing both sides, in a way. They have this “Belt and Road” initiative, basically building the Old Silk Road from China west through Central Europe, Southeast Asia, North Africa—building ports all through Africa. They want to play a leadership role in Paris. They see that they have to go clean. They’re the number one producer of solar panels in the world. They made that decision early on—they subsidized those factories, helped make solar cheap for the whole world, actually.

At the same time, they go to countries like Nigeria and say, “Hey, you need more energy. We’ll build a coal plant for you.” Now, that’ll work for three to five years, I think, before it becomes clear as day to people in almost the entirety of the developing world that solar is a much cheaper way for them to go as well.

Is there a way for Africa to realize its potential and lead with energy—with solar power?

The most important power in the 21st century is people power. It’s an innovation economy, and the more people you have who are educated, well-fed, able to work in innovation, R&D, and the service economy, the faster your economy boosts the ideas that you can then export and profit from. And in sub-Saharan Africa, and in India, Pakistan, Bangladesh, South Asia, people power is largely wasted because [a collective] 1.3 billion people are living without electricity.

Electrifying those people gives their kids the ability to study at night, it gives them internet access, it gives them the ability to start small businesses, it gives villages the ability to start factories, and so on. That pulls people into the 21st century.

We’re going to increase the output per person for a long time—but one competitive advantage becomes: Where is the energy the cheapest to make stuff? The cheapest solar power in the world is going to be, primarily, in sub-Saharan Africa and India, and that’s an advantage to them.

How do people overcome the resistance that’s inherent with the sunk cost?

This has been policy-driven. If you look at a map of the world and how much sunlight falls on different parts of the world, Alaska is really dark. Right? Well, what’s similar to Alaska [where harvesting solar energy might seem impractical] is Northern Europe, and the place that solar started was Germany. And, god bless them—because it made no sense at all for Germans to start deploying solar.

They started this flywheel thing: Solar got deployed, it hit scale, money was invested back in R&D. And the businesses making solar got more efficient in their processes—more labor-efficient, more energy-efficient, more resource-efficient—and so the cost of solar dropped.

There will hit a point pretty soon when all new electricity generation we’re building is solar and wind, and then we’ll face a decision: What do we do with the old stuff?

We’ll phase out coal first because it’s more evidently dirty. It produces not just climate change, but smog and air pollution; it causes lung disease and heart disease. Natural gas will probably last longer because, aside from the carbon emissions, natural gas has fewer health effects than coal. But eventually, we’ll phase most of that out, too.

Are you concerned about the growth of power needs for computation?

The last numbers I saw were that IT, globally—data centers, your iPhone or laptops, whatever—is close to 15 percent of electricity consumption in the U.S. That’s more than aviation.

It’s a shocking number, but, fundamentally, we have access to huge clean energy resources, so as we switch to clean energy, there’s no reason we can’t support that, even with rapidly growing percentages.

Despite the rise of IT energy use, energy use per capita in the U.S. is lower today than it was in 1970. That’s because we’ve gotten so much more efficient. If you look at American homes, square footage of home per capita is triple what it was in 1950, yet home energy use per capita is the same as it was in 1950.

Fundamentally, if we needed 10 times the energy for humanity to lift five billion people who don’t live a developed-world existence out of poverty, and to double [the developed world’s] energy use, all of it being computation, all of it being VR, we could do that. Nothing prevents us physically and economically from doing that and having it all be clean.

How much of the efficiency improvement comes from modeling and the computational side versus the actual material science?

As we build bigger and bigger wind turbines, if you double the length on a wind turbine blade, you quadruple the energy. It’s just learning how to build those, how to get the parts to the right place.

But there are amazing places where software comes into play. There’s this great example in Colorado. Colorado’s one of the windiest states in the U.S., and wind power is the cheapest power you can buy in Colorado. So the utility there, Xcel Energy, said, “Look, we’re maxed out. Because wind power goes up and down, we just can’t put any more on our grid.”

Some people from the Department of Energy facility in Boulder called NREL, National Renewable Energy Lab, took data off of all of these wind turbines and built an algorithm that would use that data in real time to better look ahead at what the wind was going to be like in five minutes, 15 minutes, an hour, four hours, a day. Getting that better data let the utility route the energy better, ramp up the natural gas plant to fill in if it was going to be a bad period, and triple how much wind power they could use on the grid.

Is there an inevitable progression at this point that takes us to using only renewables?

I don’t want to leave your readers with just a sense of kumbaya, because we’re in a race between how fast climate change is happening and how fast we’re going to deploy this stuff. And even right now, it’s not at all clear that we’re winning.

It’s not realistic that we’re going to keep deploying 40 percent more solar every year in perpetuity. Eventually, that rate’s going to slow, and nobody really knows how to forecast that.

Do you feel that there could be a tipping point in which there’s a dramatic change?

Supply arrives to meet demand. Most of the forecasts of how fast we’ll decarbonize pause at a consistent rate—we have to decarbonize at 3 percent per year—but that’s not what it looks like if you imagine solar constantly doubling or growing as fast as it is [right now]. [We would need] a faster pace of decarbonization 10 years from now than we have today—faster at 5 years, faster at 10 years, faster at 15 years. I think we might see carbon emissions from electricity and transport really do something like that: Suddenly, in a span of five or ten years, take a big step down.

As a futurist and a sci-fi author, what are our odds of survival?

Our odds of survival are extremely high. But climate change is going to hit the poorest people hardest. If you’re in Bangladesh or sub-Saharan Africa or India, you will suffer the most—although it’s been the Americans and Europeans and Chinese that run the emissions—but we are going to survive. That’s not a question in my mind at all, but the question is: How long will the scars last? How deep will those scars be?