The problem with that line of reasoning is that climate scientists have jobs too, and they get money for promoting their viewpoint just as the coal industry does. It's hard to argue coal workers have "vested interests" but science workers don't.
In fact if you investigate it, you'll find a lot of so-called "climate change denial" is not so much denial as skepticism about the robustness and motives of climate science. There are some remarkably famous climate change skeptics you wouldn't expect, like a former head of Greenpeace who wrote an interesting essay that basically claimed oceanic acidification (due to extra CO2 being absorbed) was junk science. I didn't bother digging in to the merits of that specific debate, but when even the former heads of ecological charities are flagging problematic scientific practices, and when I've witnessed quite a bit in other non-climate fields, it's not a big stretch to believe that academia may have been exaggerating or mis-interpreting things to unlock grant money. Certainly other areas of science have developed a big problem with that (p-hacking etc).
In fact if you investigate it, you'll find a lot of so-called "climate change denial" is not so much denial as skepticism about the robustness and motives of climate science. There are some remarkably famous climate change skeptics you wouldn't expect, like a former head of Greenpeace who wrote an interesting essay that basically claimed oceanic acidification (due to extra CO2 being absorbed) was junk science. I didn't bother digging in to the merits of that specific debate, but when even the former heads of ecological charities are flagging problematic scientific practices, and when I've witnessed quite a bit in other non-climate fields, it's not a big stretch to believe that academia may have been exaggerating or mis-interpreting things to unlock grant money. Certainly other areas of science have developed a big problem with that (p-hacking etc).