China’s shift to clean energy is saving the Paris Climate Accord

Yet the global shift to clean energy is barreling ahead—driven largely by China’s emergence as a clean-tech superpower. China’s massive manufacturing investments in the sector have sent the cost of clean energy plummeting, making it competitive with fossil fuels in many markets with few or no subsidies.

As governments gather in Belem, Brazil, for the annual United Nations climate conference, China sits at the center of the negotiations like never before. Beijing’s turn to clean energy is helping keep the Paris accord intact, despite developing nations’ frustration with Western backsliding on climate goals.

But China is also the largest emitter of greenhouse gases, and it has yet to begin cutting emissions—a big reason why global warming is on pace to crash through the temperature targets of the accord.

When the agreement was signed in 2015, few predicted how quickly Chinese clean tech manufacturers would achieve astonishing scale, particularly in solar panels, batteries and electric vehicles. Back then, electric vehicles and batteries were barely mainstream.

“China has become the supermajor of clean tech over 10 years," said Patrick Pouyanné, chief executive of TotalEnergies, the French oil and gas producer that is also one of the world’s biggest investors in renewables. “We didn’t really see it in 2015, but the acceleration has been spectacular."

“We can cry about it, but in a way it’s good for the planet," he added.

Now Chinese manufacturers are flooding global markets with solar panels, batteries and electric vehicles. The cost of solar power is less than half what analysts in 2015 predicted it would be in 2025. Electric vehicles in China are now cheaper than combustion vehicles, and low-cost models from Chinese giants such as BYD are pushing Western automakers to bring down prices. Meanwhile, China’s rapidly expanding production of batteries, for vehicles and grid-level storage, has slashed the cost of those products.

For poorer nations, the plummeting cost of clean energy is helping offset a sharp drop in climate finance from wealthier nations. Last year at COP29 in Baku, Azerbaijan, developed nations agreed to channel $300 billion to the developing world a year starting in 2030. Months later, Trump ordered an end to all U.S. climate finance as one of his first acts in office.

That matters less when one of the cheapest sources of electricity in many developing nations these days isn’t coal but solar panels paired with batteries, both made in China. In India, companies are now ordering thousands of megawatts of solar panel and battery capacity from Chinese manufacturers without a dime of subsidized financing from the West.

“Across all regions, renewable technologies demonstrate clear cost advantages over conventional generation," said Ahmed Jameel Abdullah, senior analyst at energy research firm Wood Mackenzie. “The global energy transition is accelerating at an unprecedented pace."

While renewables produce cheap power when the sun is shining or the wind is blowing, their intermittent nature adds costs to the broader grid, analysts say. Natural-gas plants currently fill the gaps, but batteries are becoming cheaper and increasingly viable as an alternative.

The signing of the Paris accord marked a high point in global cooperation on climate change. The agreement, adopted by more than 190 countries, called for governments to limit global warming to “well under" 2 degrees Celsius since the dawn of the industrial age and strive to limit it to close to 1.5 degrees.

Most analysts now believe that the 1.5 degree goal is out of reach. Global emissions have surged since the agreement was signed, and China is a major culprit. Its emissions of carbon dioxide jumped from around 10 billion tons when the agreement was signed to over 12 billion tons last year, around a third of the global total. U.N.-backed climate scientists say global emissions need to fall 43% between 2019 and 2030 to keep warming to 1.5 degrees, yet greenhouse gases have continued to rise through the middle of the decade.

The average global temperature last year was 1.55 degrees higher than the preindustrial temperatures, the first year in which annual temperatures exceeded 1.5 degrees. That doesn’t necessarily mean the Paris threshold has been breached—scientists typically use 10- or 20-year averages—but the unexpected rise underscored how little margin remains.

Rather than accelerating their climate efforts, some Western governments are pulling back, and the Trump administration is trying to reverse the shift away from fossil fuels. Last month, the International Maritime Organization delayed new rules, endorsed by the shipping industry, that aimed to cut greenhouse gases from the sector, after the U.S. administration threatened to block ships from countries that supported the agreement.

“The United States will NOT stand for this Global Green New Scam Tax on Shipping," Trump wrote on social media.

Trump’s “Big Beautiful Bill" ends tax credits for wind and solar projects that haven’t started construction before July 4 of next year. Still, there is significant momentum in the U.S. system: Nearly 2,000 gigawatts of capacity, overwhelmingly from renewables and batteries, have sought permission to connect to grids across the country. That is more than the current installed generating capacity of the U.S., and many of those projects will qualify for tax credits, analysts say.

In Europe and Canada, the inflationary shock fueled by the reopening from Covid and the war in Ukraine has sowed a backlash against taxes to fund renewables deployment. Canadian Prime Minister Mark Carney has canceled plans to impose a carbon tax paid by consumers.

In Europe, where electricity prices soared in recent years, governments are cutting taxes that fund renewable-energy subsidies and trimming electric-vehicle incentives. Taxpayers are also bearing the cost of new transmission lines needed to carry renewable power to where it’s used.

But in both the U.S. and Europe, analysts and investors say onshore wind, solar and batteries are able to compete with fewer subsidies thanks to the sharp decline in their costs.

“Solar plans, wind projects onshore or battery storage—these are coming at very competitive cost when compared to other sources of energy," said Stefano Goberti, chief executive of Plenitude, a unit of Italian energy company Eni that invests in clean energy in Europe and the U.S.

Much will depend on China’s emissions trajectory over the next five years. Beijing recently announced its updated climate plan under the Paris accord, disappointing environmental groups because it didn’t set a target for peak greenhouse gases.

But China’s emissions growth has slowed sharply in recent years because of its massive installations of wind and solar power at home. Its coal and gas-fired generation are down 1.2% this year.

Another variable is the emergence of artificial intelligence; China’s voracious demand for electricity is putting pressure on governments to add generating capacity as quickly as possible. In most markets these days, energy executives say, the best choice is renewables.

“There’s a five-year wait now for the new gas turbines," Pouyanné of TotalEnergies said. “If they want to increase capacity, the most readily available options today are solar and batteries."

Write to Matthew Dalton at Matthew.Dalton@wsj.com