Walmart Inc. has cut 230 million metric tons of greenhouse gases out of its supply chain in the past three years, putting the world’s largest retailer on track to achieve its 2030 emissions goal.

In the four years since it was founded, Convoy Inc. has assembled a lineup of big-name investors that includes Bill Gates, Jeff Bezos and Marc Benioff. It’s adding one more to the list: Al Gore.

UPS Inc. has agreed to buy the equivalent of 170 million gallons of renewable natural gas from Clean Energy Fuels Corp. over the next seven years in what the company described as the biggest-ever deal involving the alternative fuel.

Amazon.com announced it will disclose its carbon footprint later this year, giving consumers and investors new insight into the environmental cost of its popular two-day shipping.