Not having children is one of the easiest ways to contribute to solving climate change, which is exactly why we should encourage it regardless of whether the person is also taking other steps to solve it (which we don’t know). Not having a child also saves 58 tons of CO2 emissions per year, so it’s one of the most effective things you can do to fight climate change too, so that simple action does a lot to fight for a better world.
Source: https://amp.theguardian.com/environment/2017/jul/12/want-to-fight-climate-change-have-fewer-children
I’d do something g similar except ride all the electric interurban trains that no longer exist.