Really depends on HOW they are investing IMO.

2B in equities won't really do anything other than raise the stock prices for green technologies.

2B in green bonds or direct funding may help to move the needle if the case is that these companies are cash strapped.

But, IMO, the thing that will actually move the needle more than anything else is if Amazon takes that 2B and actually goes out and builds out renewable sources and replaces their delivery vehicles with EVs. Because, simply investing in a company that does green things doesn't guarantee actual change.

It would be a sizable impact if they powered all their services with renewable sources, especially if they don't fall back on the grid (so building out storage for themselves).