Before we discuss the funding situation with climate research, let's discuss the funding situation against climate research. If indeed climate scientists were pay-for-play, don't you think some of the richest companies in the world would be better at finding credible people to parrot talking points that serve their financial interests?
You just named “for example” the first and fourth biggest companies in the world. Look up what the third is.
I don’t know how “influential” big oil is, but I know they’re collectively quite rich. Collectively substantially richer than whoever you’ve imagined stands to gain from a shift away from carbon and has been willing and able to buy out the world’s scientific community for decades now. They can’t even pay their own scientists to shill for them; they knew about climate change since the 70s [0].
Edit:
lol the list of companies I was looking at was by market cap. A list by revenue [1] makes your case even worse: five of the ten richest companies in the world sell oil. Another eight are in the top 50. Somehow no obvious boogeyman bicycle manufacturers to be manipulating the scientific consensus though.
