Bill Gates is optimistic about climate innovation, even though the 1.5C goal is not possible.

Bill Gates thinks of himself as a realist when it comes to climate change, even if that means admitting that the world can’t keep warming to 1.5 degrees Celsius.

“Given the size of our industrial economy as a whole,” he said, “we’re going to have to do mind-boggling work” to keep warming below 2 degrees.

But what about the 1.5 °C goal in the Paris Agreement? Gates told Reuters in a video interview that no one wants to be “the first to say it,” but the math shows that it’s no longer possible.

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The software developer-turned-philanthropist was still optimistic about climate innovation. He listed a number of areas where funding from the Breakthrough Energy Group, which Gates started in 2015, was helping to advance low-carbon technologies.

Gates has put more than $2 billion into technologies that help the environment, such as direct air capture, solar energy, and nuclear fission. TerraPower, a fission company that has been a part of Breakthrough for 14 years, wants to have a demo reactor running by 2030.

Gates, who helped start Microsoft Corp., said that these things take time (NASDAQ: MSFT).

Gates talked to Reuters before his annual letter came out. He talked about 2022 and what he was most excited about for the coming year.

He gave $20 billion of his money to the Gates Foundation’s endowment. The Gates Foundation plans to spend an extra $3 billion on public health and education over the next few years.

He also praised Warren Buffett for his help, which, according to Gates, has been worth $45 billion since 2006 when the value of Berkshire Hathaway (NYSE: BRKa) stock is taken into account.

Breakthrough Energy, on the other hand, is not part of the Gates Foundation. In his letter to shareholders, Gates says that philanthropy alone can’t solve the problem of climate change.

He told Reuters, “There’s not enough money, so you have to come up with new ideas.” “There’s just no way that it can be done by force of will.”

He says that companies need money and technical help to get their low-carbon ideas past the pilot stage and then scale up production. But any money made by Breakthrough Energy goes back into the group or to the foundation.

Some of the breakthrough companies working on Direct Air Capture (DAC), which is a way to pull CO2 right out of the air, are hoping to get some of the $3.5 billion in new U.S. contracts to build DAC plants and pay for research grants.

“We have a number of direct air capture companies that will bid on being a part of those projects,” he said, adding that the recent Inflation Reduction Act has made climate innovation more likely. He didn’t say more about what the DAC companies were going to do.

He said that the steel and cement industries have made “fantastic” progress in manufacturing, which is different from how he felt about that sector just two years ago.

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About a third of the world’s greenhouse gas emissions come from the manufacturing industry.

Now, “there’s no area of climate change mitigation where I feel like, ‘Oh, that’s really covered,'” he said.

Instead, he said that now that the world is going to warm by more than 1.5C, the challenge is to help people adjust to a harsher, hotter future.

“In addition to reducing the effects of climate change, which will still be the biggest part of Breakthrough Energy’s investment, we will also pay for work related to adaptation.” This could mean using technology to help stop forest fires, building structures like coral reefs to stop flooding, or making crop strains that can survive drought.