Is it harder than physics?

Which is harder to understand, physics or earth system science?  Which is more important to get right? Which do film-makers try hardest to get right? Oliver Morton, on his Heliophage blog, says

a lot of people, both film makers and film discussers, think getting physics right, or at least seeming to or trying to, is in some way more important than getting the science of the earthsystem right. This shows, to my mind, strange priorities. The carbon cycle is a lot more easy to understand than general relativity…

He comes to this conclusion in the light of a number of films he’s seen this year. I’m not really a movie person, so don’t know if his impression is representative. But I get uncomfortable whenever I see gross misrepresentations of science, or stuff that’s just plain wrong. And, anyway, the carbon cycle, water cycle and all the other earth system stuff is mainly just physics and chemistry (with a small amount of biology thrown in).