This progress hasn't resulted in steep reductions in greenhouse-gas pollution Efforts to keep global temperatures in check are being hampered by conflicts in the Middle East and the global economy.

Gates has seen a lot of promising investment and industry trends. He and other investors in his initial $1 billion fund were worried that they wouldn't find enough promising startups to invest in. More than 100 companies working on long-duration energy storage, meat alternatives, efficient buildings, clean steel, and other means of driving down emissions have been supported by the firm.

Gates said he was amazed by the progress he had seen on some of the hardest technical challenges of climate change.

Gates said the firm plans to do several more after closing another $1 billion fund. It has expanded its mission by pushing policies and creating fellowships.

Gates noted that venture capital investments in clean energy, which were close to their ebb around 2015, have come roaring back.

The Inflation Reduction Act, the CHIPS and Science Act, and the Infrastructure Investment and Jobs Act were all mentioned by the energy secretary.

She said that they are game-changers that will accelerate the nation's shift to clean energy and boost the US economy.

The Department of Energy is trying to kick-start the construction of low-carbon hydrogen hubs, grid energy storage projects, and plants that can suck carbon dioxide out of the air, creating a "bridge to bankability" for these emerging industries.