http://www.slate.com/blogs/bad_astronomy/2015/02/10/global_warming_adjusting_temperature_measurements.html?wpisrc=burger_bar
The premise of his claims I don't understand. The claim isn't that things are warming, the claim is that the data has been restated to make it appear worse than it is. So his second claim in the article is odd. I love the claim he makes about "independent" Berkeley Earth....but whatever.
The issue is they are making adjustments to some data points going back to the early 1900's to adjust for what they believe are anomolies, etc. That begs the questions of how much of a change, why the change, who decides the change and impact? This gets back to my argument about sharing the data, the models and the transparency within....which is completely lacking.
On a side note, we have a temperature station in our town that is used to collect data. It is literally right next to the sidewalk and about 8 feet from a major 4 lane (each way) road. The amount of heat that comes off the asphalt and concrete is amazing....when they resurface the streets around here, it is truly amazing. These are the kinds of things that cause a lot of people pause about the collection, potential manipulation, etc. Climate is complex as hell.