This has been going on for a long time. What's new is that somebody got the media to notice. They gave a small number of examples, but I hope that people come to realize that this problem is pervasive throughout the temperature data, that it's actually much worse than just temperature manipulation because half of their raw temperature data is now fabricated by interpolating from other stations (the z-data) instead of read from real thermometers. Then every few years they modify their modified data, and the result is always the same: make the past even cooler relative to the present. Please don't fall victim to their "homogenization" explanations, as none of them explain the large amount of deviations that they apply, and as far as UHI, after arguing for years that it doesn't exist, now they say they are using it -- except that it does the opposite of what they say. They use it to warm the cooler stations, instead of to scale bake recent heat due to urban growth. So obviously it wouldn't make the past cooler. Listening to their explanations is like listening to Josh Earnest explain that the Paris deli attack was an attack against random people by random people of no particular faith.

Look at the chart and remember: all the all-time heat records from the 1930's never happened, the thousands of people that died from heat stroke in '34 and '36 never happened, the nationwide drought never happened, the dust bowl never happened. 2014 was the hottest year on record. Keep saying that to yourself while you bow towards Gavin Schmidt in his high office above Seinfeld's deli in NY, and you shall join the ranks of the true believers.