claim: [T]he raw data, the actual thermometer data[...] shows that the US has been cooling for 80 to 90 years. But the graphs they release to the public show warming trend, and it's all because they've altered the data.
evidence: This was very disturbing to both NASA and NOAA. Their CO2 warming theory was failing badly, so they simply changed the data, turning cooling into warming. This happened at the same time Michael Mann was erasing the Medieval Warm Period. The blue line below shows the five year mean of the average annual temperature at all NOAA United States Historical Climatology Network Stations. The red line shows the graph they release to the public, and has been highly altered to create the appearance of warming – which does not exist in the thermometer data. If they believe there is error in the data, the correct way to handle it is to leave the data intact, and put error bars on it. Not alter the data and pass it to the public as if it represents the actual thermometer data.