Even the crotchetiest and most out-of-touch people I know basically accept that the Earth is warming now. They just either disagree on the cause or proportion.

Some people just naturally resist hyperbole or sensationalist rhetoric, and I find it very helpful to reframe the argument from doom and gloom and fire and brimstone to something more realistic and grounded:

"The longer we put off doing something, the harder and more expensive it will be in the future. In a Pascal's Wager sort of way, many of the changes we are talking about don't even really cost us anything, and the potential that C02 is not a real culprit is more than made up by danger that it is. Making changes now is the prudent and financially sound decision."

In a large part, this is what the brief ESG trend on the stock market was briefly about before it got co-opted by a dozen different competing messages.