NASA prominently features this graph of "global temperature" showing very close agreement between different data sets by different government agencies since 1880.
I am going to show you the evidence now why the only way this could have happened is via collusion between the agencies. There is not enough data available to generate a coherent global long-term temperature record, much less have close agreement by independent agencies.
In 1978, the New York Times reported there was too little temperature data from the Southern Hemisphere to draw any reliable conclusions.