Its a bad argument.
The right argument (which still won't do enough convincing) is that global warming is obviously real, already happening and comes with massive future costs
Again, the investments required in the present day to hopefully and potentially reduce those massive future costs you're speaking of are resources that have alternative uses. One can compare, say, the Germany of today which gave up on nuclear power and built solar panels and wind farms and now is experiencing a decline in its industrial capacity due to expensive and unreliable energy, to an alternate-universe Germany that kept its nuclear reactors and perhaps even built some additional coal and gas powerplants.
The former undoubtedly has lower per capita carbon emissions, but the latter perhaps has the advantage in building sea walls, reservoirs, and such infrastructure and heavy machinery that would help manage a changing climate. Can you really say that one approach is sure to be cheaper than the other?
Consider this: the WMO estimates that in the 50 years from 1970 to 2019, the number of deaths around the world caused by weather-related disasters dropped threefold[0], even as atmospheric CO2 went from 325ppm to 410ppm and the global population more than doubled. That's not one-third the per capita death rate; it's one-third the absolute number of deaths. Why? Because of improving technology, enabled by increased energy expenditure per capita, that allow people to better master their environments.
It takes a lot of resources to allow weak hairless apes to thrive around the globe; we don't all live in the climate of San Diego or Corfu. And insofar as fossil fuels remain the most economical way to allow increased energy expenditure per capita, I see no reason why we must zealously and immediately stop its use.
I am all for that increased energy expenditure per capita by any means possible. I hope that one day we will have the technology to do so with minimal environmental side-effects. But we must continue to grow to get to that point. I don't believe that Net Zero will get us there; I believe it will forever chain us to the vagaries of our surroundings.
