Of course they don’t believe it.
If it were as bad as they say then it is too late for remedial action and they’d be better off figuring out a way to manage the problem.
If they believed climate change was going to cause sea level to rise 5 feet in the next 20 years as they claim they’d be advocating to hire every available Mexican to build a sea-wall from Port Isabel to the Saint Lawrence Seaway and another one down the West coast. Since they are not doing that they don’t believe the threat is that serious.
which would cost much less than their 'solutions'.