Yesterday marked a milestone in the world of corporate sustainability, prompting a flood of praise from environmentalists.

Then came the criticism.

At issue is Daimler AG’s announcement that it plans to make its passenger fleet carbon neutral by the end of 2039. It appeared to mark the most ambitious commitment of any automaker to clamp down on planet-warming emissions (Climatewire, May 13).

“To us the Paris Agreement is more than an obligation—it’s our conviction. And we have set a clear course to help prevent further acceleration of climate change,” Ola Källenius, the incoming CEO of the German automaker, said in a blog post yesterday.

The news from the owner of Mercedes-Benz drew swift praise from greens, who noted that transportation is now the largest source of emissions in the United States.

“Today’s announcement is a new start for the automotive industry to take on its full responsibility in tackling climate change,” Helen Clarkson, CEO of the nonprofit Climate Group, said in a statement yesterday.

But as the day wore on, greens began to point out some perceived flaws with the company’s pledge to slash emissions.

For one thing, Daimler’s commitment hinges on 2039, whereas a recent report from the Intergovernmental Panel on Climate Change warned that the world has until 2030 to stem catastrophic climate change.

In particular, the IPCC report called for cutting greenhouse gas emissions 45% from 2010 levels by 2030 to avert the worst impacts of global warming, including more extreme drought, wildfires and food shortages for potentially hundreds of millions of people.

“I think it’s really positive that they’re setting a goal. The majority of automakers have not set similar goals. But at the same time, it’s important to keep the context in mind in terms of where we need to go. The IPCC report calls for a 45% reduction by 2030,” said Carol Lee Rawn, senior director for transportation with Ceres, a nonprofit that works with businesses and investors to promote sustainability.

Madeline Page, clean cars campaign coordinator with Public Citizen, said she also would have liked to see Daimler provide a faster timeline.

“Every week we get even more and more urgent warnings about climate change,” Page said. “I think to confront that threat, we need to get to zero-carbon emissions as soon as possible across sectors.”

In addition, Daimler failed to clarify whether its commitment applies to the vehicles themselves or whether it extends to their life-cycle carbon emissions.

That’s an important distinction. The former means that all Daimler vehicles would be zero emission by 2039, whether they were electric or powered by hydrogen fuel cells. The latter means that Daimler would continue to produce gasoline-powered cars through 2039, but it would purchase carbon offsets to compensate for the pollution from their tailpipes.

“It’s hard to tell exactly what they mean by becoming carbon neutral by 2039,” said Kate Larsen, who leads transportation research at the Rhodium Group, an economic consulting firm with a focus on climate policy.

“If the goal really means that the vehicles themselves will be zero emission rather than offset, I think that is ambitious and in line with where we need to be to meet our climate goals, with the caveat that all other sectors of the economy also have to do their part,” Larsen said.

Dan Becker, executive director of the Safe Climate Campaign, agreed with this sentiment.

“The worst thing about a car is what comes out of its tailpipe,” Becker said. “Carbon neutral could be wonderful for the planet if it means you’re dramatically reducing emissions, and less wonderful for the planet if it means you’re only [offsetting] the emissions by planting a bunch of trees in Guatemala.”

Asked to clarify, a Daimler spokesperson provided a vague statement that did not alleviate the confusion.

“We regard sustainability along the entire value chain,” the spokesperson said in an email. “This includes concrete measures including the supply chain, the production of vehicles, the vehicle-use phase and recycling concepts.”

Finally, greens faulted Daimler for not censuring the Trump administration’s rollback of greenhouse gas and fuel economy standards, which stands to undermine its strides toward sustainability in the United States.

“If Daimler is serious about cutting global warming pollution, they should announce their opposition to Trump’s rollback of the clean car standards and attack on California’s Clean Air Act authority,” Becker said.

Page noted that Mercedes-Benz is a member of the Alliance of Automobile Manufacturers, a trade organization that lobbied the Trump administration to relax the car rules.

“I do question Mercedes’ continued involvement in the Auto Alliance,” Page said. “How does their membership in the trade association go with their announcement today? One way for them to make clear that today’s announcement is made in good faith would be for them to take a strong stance against the rollback.”

She added: “It’s positive to see voluntary commitments, but they just aren’t enough. And that’s why we need standards in the first place.”

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news