I think it will change when the people that don't believe in global warming die off, ala 'Science progresses one funeral at a time'. For the US, that's basically Boomers and Gen X [1], so I still think your 10 - 20 years estimate is decent (they don't have to _all_ die, but as more pass away I expect progress)

[1] https://www.pewresearch.org/short-reads/2021/05/26/key-findi...