BERLIN — Amazon says it’s buying 1,800 electric delivery vans from Mercedes-Benz, the biggest such order for the German automaker to date.

In announcing the order Friday, Mercedes said it would also join a climate initiative established by Amazon founder Jeff Bezos. By signing up to The Climate Pledge, Mercedes-Benz commits itself to going completely carbon neutral by 2039 — a move the company had already signaled last year.

Scientists say the man-made emission of greenhouse gases such as carbon dioxide must end by 2050 at the latest to avoid pushing global temperatures beyond the threshold of 1.5 degrees Celsius (2.7 degrees Fahrenheit) set out in the Paris climate accord.

The transport sector, including the surge in deliveries from online retailers like Amazon, is a major source of carbon emissions.

“We need continued innovation and partnership from auto manufacturers like Mercedes-Benz to decarbonize the transportation sector and tackle the climate crisis,” Bezos said in a statement.

Delivery Will Begin Later This Year

“Amazon is adding 1,800 electric delivery vehicles from Mercedes-Benz as part of our journey to build the most sustainable transportation fleet in the world, and we will be moving fast to get these vans on the road this year,” Bezos said.

While the e-van order with Mercedes is Amazon’s biggest in Europe, it is dwarfed by a contract it signed last year with U.S. start-up Rivian to deliver 100,000 electric delivery vans by 2030.

Daimler said the order comprises more than 1,200 large eSprinter vans and about 600 medium-sized eVito vehicles. Delivery will begin later this year.

The Brussels-based campaign group Transport & Environment said new European Union emissions standards that came into force this year require car manufacturers to improve fuel efficiency, meaning they have an incentive to sell more electric vehicles to lower the fleet average.

“Nonetheless, Amazon’s pledge shows there’s important demand for e-vehicles from delivery fleets,” said Lucien Mathieu, an e-mobility and transport analyst with the group.