NASA temperature data doesn’t even agree with NASA temperature data from 15 years ago.
2016 version : Fig.A.gif 2001 version : Fig.A.ps
NASA has altered their own data by 0.5C since 2001, yet claims that everyone agrees within about 0.05C.
The Japan Meteorological Agency has altered their own data by a similar amount. In 1975 they showed no net warming in the Northern Hemisphere from 1900 to 1970.
But the story gets much worse. Phil Jones from CRU said that much of the Southern Hemisphere data is “mostly made up.”
In 1978, experts said there was no end in sight to the 30 year cooling trend, and that data from the southern hemisphere was too meager to be reliable.
TimesMachine: January 5, 1978 – NYTimes.com
The 1990 IPCC report showed that there is insufficient data over much of the earth to determine temperature anomalies.
All of the agencies in the NASA graph at top use the same NOAA GHCN data for most of their database, and that data has 80% loss of stations over the past 30 years.
The only reliable long term data is from the US (which shows no warming in the raw temperature data over the past 80 years) and a few other isolated locations.
Long Record GHCN Analysis « the Air Vent
NASA has massively altered their US temperature data since 1999, to make a 1930-2000 cooling trend disappear.
The published NOAA US temperature graph doesn’t even vaguely resemble their own underlying data.
The claimed agreement in temperature data is simply not legitimate. The people involved know that their data is inadequate, tampered and largely made up. They all use basically the same GHCN data set from NOAA (which has lost more than 80% of their stations over the past few decades) and E-mails show that they discussed with each other ways to alter the data to make it agree with their theory.