by Paul Matthews, June 30, 2019 in ClimateScepticism

The history of climate scientists adjusting data to try to make recent warming look greater than it really is goes back quite a long way – it’s a regular topic at Paul Homewood’s blogfor example. But climate scientists continue to do it, giving the sceptics plenty of ammunition. Here are three recent blog posts discussing how climate scientists continue to adjust data to exaggerate warming.

At Pierre Gosselin’s blog there’s a guest post by Kirje from Japan, on NASA GISS temperature adjustments. In the latest GISS version, V4, the supposedly “unadjusted” data sets are different from the unadjusted data in the previous version V3.

Tony Heller has a graph of the 2000, 2017 and 2019 version of NASA GISTEMP, showing that Gavin Schmidt and his team have managed to crank up  warming, particularly in the era of the inconvenient pause. You can also see this effect in fig 2 and fig 4 of the GISS history page.

Here in the UK, the HadCRUT4 team are doing the same thing. Clive Best asks Whatever happened to the Global Warming Hiatus? The answer is that they have demolished it with a sequence of adjustments to the data. HadCRUT3, as published in 2014, shows a clear pause, with no warming from about 2001-2013, but the latest new improved data set HadCRUT4.6 cranks recent temperatures upwards. Clive thought that night be due to including different measurement stations, but checked and found that was not the case. The numbers have simply been adjusted.

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Here the red diamond is the raw data, the green diamond is HadSST3, and the new HadSST4 is shown as the black line, with grey shading representing uncertainty. In the early years of the 20th century, there was global warming that doesn’t fit with the carbon-dioxide-controlled theory of climate scientists, so that is adjusted downwards. But look at the trend over the pause era, since 2000. The raw data shows literally no trend at all. HadSST3 adjusted the trend upwards to create warming, and HadSST4 adjusts things upwards again, roughly doubling the previous adjustment. And this is in an era when the data quality should be excellent, thanks to the introduction of the ARGO float system.

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