I think the USGS seems authoritative enough to trust on this one. It does seem the Global Warming Swindle documentary messed up with on that point. I hope they edit that part.
Side note: I'm probably going to be a way from FR at least a few days as work on stuff I actually get paid for. Its been fun poking my nose into this debate.
Check my profile in point #5. There's a link to a site that lists the numerous errors in the show. Releasing the DVD might actually be a good teaching moment; professors could have their students research various errors in the show and demonstrate why there are wrong.
Side note: I'm probably going to be a way from FR at least a few days as work on stuff I actually get paid for. Its been fun poking my nose into this debate.
I'll be gone until the second week of May, too.