I'm guessing the reason he doesn't take money from the fossil fuel industry is because he just can't be bothered with such trifling sums. The average salary in the US is more like $350k or $400k, IIRC. 120k is for total losers.
Not sure if this is true on the other side of the pond (though I'd be surprised if it isn't in the rough ballpark), It typically costs about double someone's salary to employ them in a university (office space / equipment, part salaries of admin staff, technicians, tax obligations and so on). That means that, assuming that the $120K/year is paid to him as research grants and not a gift, it allows him to pay a salary of about $60K/year. On our pay scales, that's near the top end of what we pay postdocs and the low end of what we pay lecturers (associate professors, I think, in US terminology). Any equipment that you might need for a particular project, plus travel expenses, are extra.
It's a nice amount to have, but it's not enough to fund a faculty member full time. If it's guaranteed funding over 10 years, then it's definitely worth chasing. If it's money that just turns up as a gift, that's great. If it's something that requires the normal grant application process, then it's probably less attractive than normal funding bodies.