https://www.pewresearch.org/science/2019/11/25/u-s-public-vi... "About two-thirds of U.S. adults (67%) say the federal government is doing too little to reduce the effects of climate change"
https://www.pewresearch.org/fact-tank/2019/04/18/a-look-at-h... According to this: 59% of Americans see it as a major threat and 23% see it as a minor threat. This is close to the Australia (60% and 29%) and UK (66% and 23%) numbers.
I think the media discussion in America on many issues (policing, masks/vaccines, climate change) presents a distorted view of what the majority believes, because sensational, clashing talking heads drive more ad dollars. So why don't we see more action on climate change in America? Well, some reasons: 1) Lobbying efforts often push back or at least water down any change. 3) America's two party system plays to the extremes in both camps rather than the majority viewpoint, which gets lost. 1) most people have more pressing near term concerns that dominate their choices.