To many people’s confusion, these weather events happened against a backdrop of increasing man-made greenhouse gas levels in the atmosphere that are gradually warming the planet. But scientists stress this weather does not mean that those gases are no longer exerting a warming influence. Nor does it go against the grain of basic global warming theory.
By the beginning of the 21st century, Earth ‘s temperature was roughly 0.5 . Nor does it go against the grain of basic global warming theory.
Roy Spencer explains it here