We were mistaken on a lot of things in the past and
in general we're getting better at figuring it out.
Scientific consensus is that climate change is real, is impacted by human activity, and shows no sign of abating. We're seeing weather patterns that are breaking records and seasonal changes that correspond with a warming planet.
The denial of these concerns seem to be either from those who are directly profiting from factors contributing to it or those whose political beliefs associate it with a hoax by the enemy.
Fossil fuels provided cheap energy to transform civilization but it's not the only game in town anymore. Transitioning away from them brings significant benefits that are worthy enough regardless of "saving the planet" (e.g., cheaper power, less pollution, energy independence, less environmental destruction, etc).