Well, Frederik has dealt with these kind of issues many times before and if he has done his homework, he would certainly have been able to keep a conversation about sustainable energy going for a while and beyond the more obvious.
Frederik's job here is not to achive anything by himself, but rather to lend prestige to the Danish delegation and also ensure that the right people on the right level meet the representatives for the Danish delegation, and letting them achieve something.
I think the Minister for Developement, who is very new in the job, is pretty pleased with having a more experienced Crown Prince around to take the lead, when the show is on.