I have to travel soon and I have two options. One is to fly for 3 hours, another is to take a high speed train for 11.5 hours. The flight ticket is about 100 USD cheaper than the train ticket.
My aim is to minimize the environmental impact of my travel. So taking the train seems to be the obvious choice. But I wonder if I'd better save the 100 USD and donate the money to organizations such Clear Air Task Force or Sunrise Movement, which may actually have better impact on the environment?
No, it could come from having a high-impact job (where nonzero marginal hours go into it) or from donating a fraction of the difference rather than all of the difference.
I also think that if you believe that donations to other charities have higher marginal impact than donation to climate charities, it'd be less moral to donate to climate charities instead.