We are able to measure global temperatures, and we have consistent models to predict the results of increased greenhouse gases, average temperature increases, etc.
Even the US Military is paying attention to the climate crisis, and it is a crisis.
If you think it's all a bunch of "librul hysterics," invest in oceanfront property in South Beach, or a bunch of cabins in California. Found a business that relies on coral reefs, even. 2/3s of Australia burned not long ago, and Greece just recently had devastating wildfires...many of the more volatile climate events we are witnessing are the result of global warming, predictably.
The sheer amount of ignorant and just plain stupid people we are forced to live among is overwhelming...I don't tend to be too optimistic about our chances as a species, given that roughly 30% of the US population is deeply ingrained in a death cult.