It doesn't have to be corruption of the explicit type you're talking about though, sunzi, where somebody is bought off directly for a particular point of view. There can be systemic, institutional pressures. Things like, on one side, if there's a problem, then the science becomes more important and should be more funded, and will come with more political power; and on the other side, the science is more useful to the oil company and may attract their money.
Institutional pressures, where they exist, can be universal through a whole field, so 98% would be nothing. (So, needless to say, would 2%).