The oldest temperature record in the world is from a group of weather stations in Central England. The record shows that the temperature in Central England has been increasing at the same rate for 350 years, without an acceleration during the twentieth century. The official temperature record for the world, as compiled by Hadley CRU, NOAA, and NASA/GISS, shows a rapid uptrend toward the end of the twentieth century. According to those authorities, the increase in temperature was more dramatic in the Northern Hemisphere than in the Southern Hemisphere. It is difficult to understand how there could have been such a large Northern Hemisphere increase that missed Central England. Here is an article on this situation.