NASA has corrupted the temperature record across the entire planet, in order to create the appearance of warming. The graph below shows US temperatures – Hansen 1999 in blue, and GISS in red. The graphs are normalized to the 1997 five year mean lines.
The next four graphs show how GISS has cooled the past globally, and at all three latitude bands since Hansen 1981.
Similarly, NOAA (red) has cooled the US past since their 1990 report (black)
The most damning graph of all though is the one below, showing how NOAA (red) is cooling the past relative to their own thermometer data (blue)