The UK is getting colder because the polar ice cap is melting and cooling what's left of the Gulf stream over there. In time it will cause the stream to stop reaching the UK, then you will see what global warming is. There is no doubt that the USA is getting warmer. Temps in the 40s and 50s in Maine in December is unheard of.
Of course this is all theory, and I'll simply ignore it and go to the beach on Christmas day.