2. This $33M appears to be all charitable giving by Exxon spread over more than 20 years. That's not much, nowhere close to billions of dollars.
3. The tiny amounts are a problem for them, so they say they "know" it's really a lot more. As befits a site that just makes things up, the reason they "know" is: "We assume this is not the first (or the last) contribution Exxon has made to the US Chamber of Commerce". Brilliant. Assumptions, facts, what's the difference?
Again, this isn't evidence for "billions of dollars" being spent on "increasing public ignorance". It's not even evidence for any money being spent on climate, because the reasons they donated to these various foundations isn't really known to the desmog guys. It's just more assumptions.