The energy transition has a price tag in the trillions of dollars. Securing all that funding will depend heavily on commercial and individual investors, former U.S. climate envoy John Kerry said at the Breakthrough Energy Summit in London on Thursday.

“I believe private sector is the entity that is going to solve this problem,” Kerry told a packed room during the second day of the summit. “No government has enough money to do this.”

Kerry, who stepped down from his role of climate envoy in March (see our profile of Kerry here), spoke on a panel about the state of climate action alongside John Doerr, chairman of venture capital firm Kleiner Perkins, and Kerstin Jorna, director-general of the European Commission.

If countries implement all the promises they made at last year’s United Nations climate summit in Dubai, where the world agreed to transition away from fossil fuels, then “that’s victory staring us in the face,” said Kerry.

But, he added, “the key here is private-sector investments.” The energy transition, he said, will be a “private-sector race to the top.”

Speaking to a room full of entrepreneurs, venture capitalists and cleantech experts, among other climate-focused leaders, Kerry also warned about the costs of inaction amid record temperatures, rising seas and melting glaciers.

“You have to remember, folks, we are not being driven by quarterly reports or a business schedule — we are, or should be, driven by what science is telling us.”

Asked about what Donald Trump’s re-election to the White House might mean for the United States’ clean energy transition, Kerry warned that the Republican candidate will try to undo the climate progress from the last few years, including the advances made as a result of President Biden’s signature climate law, the 2022 Inflation Reduction Act.

However, Kerry also said “the marketplace is already so committed, so big and growing” that Trump wouldn’t be able to fully stop the momentum.

Editor’s note: Breakthrough Energy supports Cipher.

More from the summit:

• Scale matters. Let’s talk about it.
• U.S. and EU must accelerate energy transition despite headwinds, say top policy advisors

Today’s Hot Takes:

• China energy leader predicts country’s renewables will cover new energy demand

Amy’s take: At the Breakthrough Energy Summit, Energy Foundation China president and CEO Ji Zou predicted China would, as soon as this year, “cover all the increase demand for power with renewables.” This would be a big deal because so far coal has continued to help meet growing power demand in China (and elsewhere in the region).

• Venture capital investor on the U.S. presidential election

Cat’s take: The potential climate policy implications of forthcoming elections — on both sides of the Atlantic —were a topic ripe for debate at the Breakthrough Energy global summit in London this week. “Right now, investing to re-elect Joe Biden is the best climate investment we can make,” John Doerr, chair of VC firm Kleiner Perkins, told reporters on the sidelines of the summit.