Stick with it, it took me a few months to figure out my first carp
But after that they start to come easier as one learns the correct presentation.
6wt-7wt, 0x-2x fluoro with a small lightweight crayfish pattern (#4-8 hook). 0x may be strong enough to break a rod if you try to fight back too much, but it will help when the fish tries to drag you through fallen limbs, rocks, piers, etc. A clear sink-tip line is my new favorite for carp; it allows for a very short stout leader while staying stealthy.
smaller than 2x seems to break easily with a hard charge (although maybe I'm just not that smooth!)
look up member 'mrp1', he has some great videos on how to know when a carp has taken your fly. Body language is everything with carp, as the eat is usually very subtle. You must cast close enough to be seen or intercepted without spooking the fish, and then the bait must 'flee' away from the carp. Crayfish going toward the carp usually freaks them out!
It pays to invest in nice hooks if you are tying your own. light, sharp, and strong are important.
Climate change? who knows, I like catching carp late into the fall!