The magnitude of the theoretically required changes in consumption to impact global climate, and therefore the extraordinary cost to humanity to make those changes in consumption, are so inconceivable that given our relatively pathetic understanding of the climate history of our planet, let alone the complex systems that result in said climate, skeptics simply aren't yet willing to commit massive resources to try to alter world climate with currently available tools.
There is also a strong belief that scientific progress will continue to reduce the cost of the "necessary changes" enough orders of magnitude so that we can get to the point where we don't have to start wars or injure billions of people in order to move the vanity metrics the specified amounts.
It's not really "who the fuck cares how the planet ends up, I'll be dead by then anyway" but rather, "in 100 years our science will be so advanced that we'll look back on early 21st century efforts to 'save the climate' and just laugh, and shake our heads at what a waste of resources it all was."