If we gotta have scientists tell us that, we have serious issues. The time for scientist warnings was like fifty years ago, when people could pretend not to see the future badness. And those warnings were there, ignored by many, especially by people in power.
They published this in Popular Mechanics in 1912, we’ve been ignoring this for a long time:
The furnaces of the world are now burning about 2,000,000,000 tons of coal a year,” the article reads. “When this is burned, uniting with oxygen, it adds about 7,000,000,000 tons of carbon dioxide to the atmosphere yearly. This tends to make the air a more effective blanket for the earth and to raise its temperature. The effect may be considerable in a few centuries.
Also, this Wikipedia article has a good summary on the overall arc of our understanding: https://en.wikipedia.org/wiki/History_of_climate_change_science
