Today: Technology companies are one of the biggest investors in clean energy, but new accounting rules could upend that; the rest of the world is following America’s retreat on EVs; U.S. Army's small nuclear reactor plan.

Welcome back: Potential changes to the way businesses measure the emissions they generate from buying electricity could upend the market for green power, according to U.S. business coalitions, WSJ Pro Sustainable Business's Yusuf Khan writes.

The Greenhouse Gas Protocol, the world’s leading standard setter for carbon accounting, is looking to update its guidance on Scope 2 emissions—the indirect emissions generated by a company’s energy use. The guidance hasn’t been updated in 10 years, and climate scientists, companies and policy makers say a review is long overdue.

GHG Protocol wants to limit the use of renewable energy certificates. Companies purchase RECs when they are unable to buy clean energy from their local grid. The idea is that by acquiring them, renewable energy is added to the grid somewhere in the world, even if it isn’t used to power the operations of the company.

Some climate scientists have cast doubt on whether RECs contribute to meaningful decarbonization, pointing to the use of solar RECs in the middle of the night, as one example of flaws in the system. They have been calling for a more granular approach, where a company’s grid emissions are tied to the location of its operations and are measured hourly rather than on an annual basis.

However, buying groups say that the changes could jeopardize millions of dollars of investment in clean energy. If companies are unable to account for RECs in their energy disclosure, they could stop buying clean energy altogether, they say.

The European Union is pushing back some of its reporting requirements for foreign companies to disclose their impact on the environment, amid mounting pressure from business leaders and policymakers both inside and outside the bloc, Yusuf Khan and Perry Cleveland-Peck report for Dow Jones Risk Journal.

A deadline for non-EU companies to adopt European reporting standards was moved back to October 2027, according to the European Commission, the administrative arm of the EU, in a letter to financial regulators outlining what it called a “deprioritization” process. The decision means that companies based outside the bloc can avoid reporting until at least 2029.

On Monday, the European Parliament also moved to limit some of its reporting requirements on sustainability to just the very largest companies.

The EU has been looking to push companies into disclosing their impact on the environment through twin legislative vehicles known as the Corporate Sustainability Reporting Directive and the Corporate Sustainability Due Diligence Directive. Under the rules, companies for the first time would have to report their emissions and also figure out a way to lower them.

The U.S. retreat from its electric-vehicle ambitions is spreading around the globe, the WSJ's Sharon Terlep and Stephen Wilmot write.

In Canada, Prime Minister Mark Carney paused an electric-vehicle sales mandate that was set to take effect next year. In the U.K., Prime Minister Keir Starmer has allowed for a more flexible timetable to hit the country’s EV targets. And the European Union last month bowed to pressure from automakers to rethink—a year earlier than planned—its 2035 target for eliminating carbon-dioxide emissions from cars.

The reality is hitting hard in the U.S. General Motors said Tuesday that it would take a $1.6 billion charge because of sinking EV sales, a shift it blamed on recent moves by the U.S. government to end EV subsidies and regulatory mandates. The automaker has lobbied heavily this year to loosen EV requirements.

That might just be the beginning of a financial reckoning from automakers that poured billions into new electric models—from sports cars and sedans to big pickups and sport-utility vehicles—to try to get ready for the government-backed EV mandates.

The U.S. military is making one of its most significant pushes yet into modern nuclear power with a program to put small reactors on Army bases across much of the country where strained power grids can’t keep up with rising energy demands, the WSJ's Heather Somerville reports.

The Army on Tuesday unveiled the Janus Program, which aims to supply bases by 2028 with microreactors—tiny reactors generating less than 20 megawatts of electricity, generally enough to power a small town. That is a fraction of the energy output that larger modern reactors can produce, but the microreactors are small enough to move on a containership or aircraft.

The reactors will help keep weapons powered and maintain critical base operations when other energy sources go down because of bad weather, cyberattacks or other grid disruptions, the Army said.

• Forget about the froth in tech valuations. The real excess might be building up in energy stocks. (WSJ)

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• TotalEnergies expects higher oil and gas production but said earnings in its LNG division will be hit by maintenance work. (WSJ)
   
• The IEA forecasts oil-supply growth of 3 million barrels a day this year and 2.4 million next, exceeding demand growth. (WSJ)
   
• JPMorgan says the U.S. will struggle to generate the energy it needs without including wind and solar. (Bloomberg)
   
• Gov. Gavin Newsom vetoed a bill that would have prevented public funding for automation at two California ports. (WSJ)
   
• A Swedish low-carbon steel start-up that is one of Europe’s highest-profile green industrial projects is scrambling to survive. (FT)
   
• Clean-energy investor Altérra is looking to developing countries as it aims to unlock $250 billion in climate investments. (WSJ)
   
• Malaysia has announced plans to introduce a carbon tax next year for high-emitting sectors, such as iron and steel. (Dow Jones Risk Journal)
   
• Spain’s grid operator Red Electrica detected two recent voltage variations but said there was no imminent blackout risk. (WSJ)

WSJ Pro Sustainable Business gives you an inside look at how companies are tackling sustainability. Send comments to bureau chief Perry Cleveland-Peck at perry.cleveland-peck@wsj.com and reporters Clara Hudson at clara.hudson@wsj.com and Yusuf Khan at yusuf.khan@wsj.com. Follow us on LinkedIn at wsjperry, clara-hudson and yusuf_khan.