The appetite for speedy package delivery is skyrocketing worldwide. Americans do more than 15% of their shopping online, with digital purchases of groceries, shoes, pet food and other goods quadrupling over the past decade to $1 trillion a year. Global e-commerce is expected to grow at more than twice the rate of offline purchases, and, by decade’s end, 25,000 packages will be shipped every second, according to an analysis by environmental group

All of this comes with a hefty climate footprint. FedEx, United Parcel Service and DHL, three of the world’s larger delivery companies, collectively emitted 92 million tons of heat-trapping gases in 2022 — more than the entire climate footprint of Greece. The industry’s emissions will likely grow as demand for last-mile delivery is expected to climb 78% by 2030, according to the World Economic Forum.

Delivery giants have promised for years to clean up their operations. vowed to make half of all deliveries with zero carbon pollution by 2030. UPS pledged to cut ground transportation emissions by 12% by 2025. And FedEx announced it would buy thousands of electric delivery trucks.