The US is not warming, so Tom Karl and Gavin Schmidt have to keep cooling the past and warming the present to make it appear to be warming. The graphs below show changes to their own data from 1999 to 2001, 2001 to 2012, and from 2012 to 2014. Note how they repeat the same hockey stick of data tampering in order to create the appearance of a non-existent warming.
Also note how they overwrite their data in place, in order to hide their constant data tampering.
current version: data.giss.nasa.gov/gistemp/graphs_v3/Fig.D.txt
1999 version: pubs.giss.nasa.gov/docs/1999/1999_Hansen_etal_1.pdf