NOAA has added more data points and "adjusted" some earlier temperature data from the first part of the 21st century, and the newly configured global temperature data set is now interpreted to show no hiatus or slow down in global warming occurred during the first part of the 21st century. This is in conflict with dozens of earlier reports from NOAA that consistently reported that following a record warm El Nino year in 1998, the Earth failed to set a new temperature record for the next 15 years. The period of time from 1998 to 2013 with no apparent global warming had come to be known as the "hiatus."
The earlier reports by NOAA of a hiatus in global warming caused both scientific and political controversy. Some politicians and political commentators opposed to the idea of global warm seized on the hiatus as evidence that the whole scientific idea of global warming warming was flawed, and predictions of the magnitude of future global warming were therefore unreliable. In the scientific community research was done and numerous papers published about the hiatus, with a wide range of scientific theories being offered to explain the hiatus. Possible reasons for the hiatus ranged from the effects of volcanoes, to heat being hidden in the ocean, problems with data quality, to simple random variations in the amount of global warming going on. But there was little doubt that the hiatus posed a problem for the scientific community. Prof. William Collins of Lawrence Berkeley National Laboratory and lead author of the modeling Chapter 9 of the IPCC AR5 said of the hiatus: "
... to be honest with you, if the hiatus is still going on as of the sixth IPCC report, that report is going to have a large burden on its shoulders walking in the door, because recent literature has shown that the chances of having a hiatus of 20 years are vanishingly small."
Now NOAA is claiming that the hiatus never even happened, and that there was no slow down in global warming during the first part of 21st century. If one accepts NOAA's new statements, they have done away with the hiatus controversy entirely by getting rid of the hiatus itself. Apparently all the earlier NOAA reports showing a hiatus, and all the scientific research done on the hiatus, and all the scientific papers published about the hiatus, and all the theories explaining the hiatus were just a big mistake. Its like NOAA made some kind of planetary "boo-boo" and now they want a "do-over."
But if the hiatus controversy is over, a new controversy now exists----this time about the quality of the NOAA global temperature data. Now that NOAA has completely reversed themselves to say there never was a hiatus or slow down in global warming, that means many years of NOAA data were wrong. And if the prior data was wrong, is the current data right?