It's a silly quote IMO, you have no idea what technology could turn the tide by then.
I think the largest fear is mass migration and war breaking out in areas below about 40 degrees latitude. This will spread north as southern regions start to get too hot for people to live.
And it is all because in the 1970s, developed nations did not want to listen to scientists and take bribes from the Oil Industry. Back then plenty could have been started, especially with the oil embargoes occurring back then.