If Amazon doesn’t know how to eliminate carbon emissions, then who does?

Amazon’s chief sustainability officer said Tuesday the company doesn’t know how it will achieve its goal of net zero carbon emissions by 2040.

“We are still striving towards that target,” Kara Hurst said at an Axios event, adding later that she is “not going to sit here and say, ‘We know all the ways that we’re going to do this.’”

The admission was both frank and realistic. It’s also a bit disappointing. If Amazon doesn’t have a plan to decarbonize, then who does?

Amazon is one of the largest companies in the world, with last year’s revenue up 12% to $717 billion — about the size of Ireland’s economy. Its rise is illustrative of how, as UN Secretary General Antonio Guterres has pointed out , power has shifted from governments to a few corporations.

As power moves, responsibility follows. The question is, how much responsibility does Amazon bear?