How do you vet the orgs you decide to donate to? ACLU is obviously an organization with a very long track record, but what about 350? The only orgs I give to with any regularity are a local park and Heifer International, the former of which I can observe with my two eyes, and the latter I take on faith as being worth my dollars; they seem like good people spending dollars wisely.
Just want to shout out Southern Poverty Law Center as another organization with a long established history of Actually Helping With Your Money. In 1979 it began to fight the Ku Klux Klan and other white supremacist groups with an innovative litigating strategy involving filing civil suits for monetary damages on behalf of the victims of hate group harassment, threats, and violence. Given the decline in such groups over the years, the SPLC has become involved in other civil rights causes, including cases concerned with institutional racial segregation and discrimination, discrimination based on sexual orientation...
I've read two of Bill McKibben's books and I agree with his message. They could be spending it all on hookers'n'blow for all I know but what they've published I agree with. McKibben's criticisms of nuclear power are largely economical and relate to externalities and subsidies; I've read criticisms of his arguments but they get really technical really fast and I don't find them compelling. Not to say they don't have merit, but to say that as a slightly-educated layman with a technical background the math isn't decisively one way or the other.