This is completely untrue. We have been measuring changes in green-up, differences in tree ring size, and the advance of species from more temperate climates into higher and higher latitudes - all consistent and easily correlated with increased warming at northern latitudes. I see further down that you list yourself as a botanist. I find that quite hard to believe. I suggest you spend some time in the literature, and use the critical and analytical thinking skills that should come with any education, but especially one in the sciences.