Most everyone (99.9%?) involved in the climate science community are fully aware of NASA's gross manipulation "enhancement" of the historical global temperature record dataset.
It's understood by all that the real 20th century warming was just not very dramatic, thus it had to be 'sexed up' to fit the alarmist fear-mongering. As a result, the NASA/GISS climate agency has shown their amazing "scientific" capabilities by producing an enhanced global warming trend.....by simply, and literally, lowering (ie, cooling) past recorded temperatures prior to 1960.
This chart clearly reveals these NASA's manipulation "enhancement" results, which are laughable, unless of course, one is unaware of the back story of manipulated "enhancing" climate science.
NASA's has done a yeoman's job keeping the U.S. mainstream press from discussing the faux global warming trend but international news agencies have less qualms about reporting the truth.
This chart comes from an international newscast regarding the fake global warming. The newscast about the chart and the political agenda behind it can be watched by clicking on the graph. Or read about it here.
Previous fabricating-fake temperature charts.