Groucho Marx once quipped: “Those are my principles, and if you don’t like them… well I have others.” Welcome to the world of global temperature setting and climate modelling where changes, no doubt for sound scientific reasons, almost invariably promote the Net Zero agenda. On Monday, the Daily Sceptic disclosed that the fifth revision to the Met Office’s HadCRUT temperature database boosted recent global warming by 14%. In fact, this was just the latest uplift in the HadCRUT series
In 2013, the slight cooling from 1998 to 2012 was transformed to a 0.04°C warming, a figure that subsequently found its way into the fifth 2013 IPCC assessment report.
The graph above, published in the climate science website No Tricks Zone, shows the change from HadCRUT3 to HadCRUT4. Overnight, a temperature flatline became a gently rising trend. At the time, many climate alarmists were worried about the pause in global temperatures that set in from around 1998. The carbon dioxide scare was becoming a potent weapon in the drive to introduce a control and command economy characterised by an agenda now called Net Zero. Scientists have spent decades trying to prove a constant link between CO2 emissions and temperatures, but to no avail. In the absence of actual proof, climate models guess that doubling CO2 in the atmosphere will lead to a rise of up to 6°C. As a result, their forecasts have long lost any semblance of reality in an era when global warming has run out of steam.
HadCRUT is a joint venture between the U.K. Met Office and the Climate Research Unit at the University of East Anglia. The latter of course was at the centre of the 2009 Climategate scandal, when a large leak of internal documents cast interesting light on some of the methods used to produce the IPCC ‘hockey stick’ graph. This graph accentuated recent warming by abolishing the substantial rises seen in the mediaeval warming period and the cooling of the little ice age.
In a paper published last month, a group of academics led by Meng Wei from the First Institute of Oceanography in Qingdao, examined the results of numerous versions of land, sea and merged temperature databases. They were said to “consistently show that the global surface temperature somewhat plateaus in 1998-2012 after the strong warming surge in 1975-97”.
Let us now look at what happened to that pause in the latest HadCRUT revision. As can be seen in the graph below, the pause was still slightly evident in HadCRUT4, but it is now no longer with us. HadCRUT5 added about 0.1°C to the record of the last 20 years and the pause has been quietly airbrushed from the historical record. The graph also shows the cooling of around 0.1°C applied before 1974, which has the effect of accentuating the ‘hockey stick’ effect of recent warming.
Announcing the fifth revision in 2020, the Met Office said HadCRUT5 was now “in line” with other datasets, adding: “the four years 2015 to 2018 are the warmest in the series… which runs from 1850 to 2018.” News that perhaps doesn’t come as a great surprise given the helpful 14% boost to the figures. As we also noted on Monday, the U.S. database run for NASA by the Goddard Institute for Space Studies (GISS) has also undergone considerable recent revisions. As with HadCRUT, these have cooled the past until the 1970s and warmed the latest recordings. Changes in temperature at GISS have been substantial with a range of 0.3°C.
One place where the pause is still with us is the highly accurate satellite record.
Between 1998 and 2012 there is clearly no increase in the global temperature. And as we have noted in a number of recent articles, the Earth is currently in another pause, this time lasting around 90 months. There are spikes from the mid-1990s caused by the powerful weather fluctuations starting in the tropical Pacific and known as El Nino and La Nina. The large upward spike in 1995 was caused by one of the largest El Ninos on record. Similar El Nino spikes are seen in 2009, 2016 (also very powerful) and 2019. Downward pushes are often caused by the effect of La Ninas.
It might be concluded that the awkward temperature pauses are the elephants in the room, so far as Net Zero activists are concerned.
But as Groucho Marx said: “One morning I shot an elephant in my pyjamas. How he got in my pyjamas, I’ll never know.”
Chris Morrison is the Daily Sceptic’s Environment Editor