A contractor working for Amazon.com cleans a delivery truck in Richmond, California, Oct. 13, 2020.David Paul Morris | Bloomberg | Getty ImagesAmazon lowered its carbon emissions for the first time since it began disclosing the figure four years ago.In its annual sustainability report issued Tuesday, the e-retailer said its activities emitted the equivalent of 71.27 million metric tons of carbon dioxide last year. That’s down 0.4% from 2021, when it reported a carbon footprint of 71.54 million metric tons. Emissions are still up roughly 40% from 2019, the year Amazon first began disclosing its carbon footprint.The company also reported its carbon intensity, which measures emissions per dollar of sales, fell 7% between 2021 and 2022, and has fallen 24% since 2019.”We achieved this in large part by improving efficiency across our business and continuing our investment in renewable energy,” Amazon stated in the report.Scope 2 emissions, which accounts for emissions from electricity use, dropped 29% between 2021 and 2022, the company said.Amazon has spent millions on wind and solar projects to power some of its warehouses, data centers and offices, and recently became the world’s largest corporate buyer of renewable energy. It’s also pledged for its entire business to be net zero carbon by 2040.Amazon said its scope 3 emissions, which includes indirect sources such as building construction and third-party transportation, fell 0.7% in 2022 after three consecutive years of increases.The company has worked to electrify its delivery fleet, including by purchasing 100,000 Rivian electric delivery vans, which it has said will hit roads by 2030. The company now has more than 9,000 electric vehicles in its global fleet, and 2,600 Rivian vans in North America, according to the report.Amazon’s climate record and the ways it measures its own environmental record have faced scrutiny, however. Employees and shareholder groups have raised concerns that Amazon isn’t meeting its climate commitments, while environmental justice groups have criticized the company’s rapid warehouse expansion, which they argue generates disproportionate environmental harms on minority communities where its warehouses are often concentrated.Amazon recently eliminated one of its climate goals, called Shipment Zero, wherein the company pledged to make half of all its shipments carbon neutral by 2030. Amazon said it “no longer made sense” to have a separate goal that applied to one area of its business, and that it would instead focus on the Climate Pledge.On Tuesday, Amazon said it would also be updating its supply chain standards to require suppliers to regularly share their carbon emissions data and set emissions reductions goals. The change will take effect starting next year.