The 1960s and 1970s were generally cold decades in the United States and around the world. This came after a few decades with general warming. That time frame, especially in the 1970s, was a period when there were articles and publications concerned over the cooling earth. Since then, most locations on the planet have once again warmed slightly.
Last week, Climate Central, a political advocacy group sent out a news release stating that Minnesota and numerous other states have recorded rapidly warming temperatures since 1970. Cherry picking is a concept of selecting the highest or lowest point in a data set to inflate your claims. Recently there have also been claims of the earth cooling rapidly since 1998, a very warm year globally. Both claims could be considered correct, but both use specific data points that do not represent the true nature of the temperature data.
As the old saying goes, there are lies, damned lies and statistics. In other words, there are a lot of agendas out there, so buyer beware.