As always, there’s nuance. You can schedule workloads, machine learning/training included, where the power is cleanest (low carbon). Google relies on electricitymap.org/Tomorrow to do this.

https://blog.google/inside-google/infrastructure/data-center...

The more folks who elect to pick where to compute based on low electrical carbon intensity, the faster the grid turns over to clean generation. You must vote with your fiat. I encourage technologists to include this consideration in their workload scheduling requirements. Renewables are almost always cheaper than fossil generation as well.

Buying more green energy creates demand for more green energy, which in turn creates more supply (wind, solar farms ...)

Meanwhile, the aforementioned transatlantic flight cannot get greener, whether Bert is trained or not.

The categorical imperative doesn't require everyone to be practically able to do the thing. Is it not moral to feed a starving man because people in China aren't able to feed him?

There's more than enough solar and wind, it's just a matter of how much we as a society want it. The green energy revolution has barely begun, and we're still climbing the learning curve. More demand means a faster climb means exponentially more green energy sooner.