A popular scare story running in the media is that the Greenland ice sheet is about to slip its moorings under ferocious and unprecedented Arctic heat and arrive in the reader’s front room any day now (I exaggerate, but not much). Meanwhile back in the scientific world, scientists are scrambling to understand what natural causes lie behind the sudden slow-down in Greenland’s summer warming and ice loss dating back to 2010. The recovery of Arctic summer sea ice has been spectacular of late, with the U.S.-based National Snow and Ice Data Center reporting that this year’s September minimum was 1.28 million square kilometres higher than the 2012 low point of 3.39 million square kilometres.
Three Japanese climatologists have recently published a paper noting that “frequent occurrence of central Pacific El Niño events has played a key role in the [abrupt] slow-down of Greenland warming and possibly Arctic sea ice loss”. Of course such findings play havoc with the simplistic ‘settled’ science notion that carbon dioxide produced by humans burning fossil fuel is the main, if not only, driver of global temperature warming or cooling – a notion that leads many green activists to claim that the climate will stop changing if society signs on to a ‘Net Zero’ CO2 emissions agenda.
For instance, a bizarre ‘fact check’ on a recently published Daily Sceptic article by Facebook partner Climate Feedback claimed there had been no natural climate change for almost 200 years. It quoted Professor Timothy Osborn of the University of East Anglia, who said: “The warming from the late 1800s to the present is all due to human-caused climate change, because natural factors have changed little since then, and even would have caused a slight cooling over the last 70 years rather than the warming we have observed.”
The Japanese scientists argue that they have been able to show that El Niño natural weather oscillations have driven “atmospheric teleconnection” and shifted the tropical rainfall zone to the north. The higher warming up to 2012 was “accelerated” by heat from the Pacific and a phase in the North Atlantic sea current oscillation that favoured warmer conditions over Greenland and enhanced ice melt. Changes around Greenland can be attributed to “natural variability, rather than anthropogenic forcing”, note the scientists, “although most climate models were unable to reasonably simulate the unforced natural variability over Greenland”.
What the scientists are talking about of course are the huge heat exchanges that regularly change the climate of the Earth. As the Daily Sceptic recently reported, Professor Richard Lindzen of MIT noted that the Earth had many climate regimes, and there have been “profound” changes in temperature between the tropics and the polar regions over millennia. Meteorologist William Kininmonth recently argued that the heat exchanges were little understood, but they are one of the great drivers of climate changes. It might be suggested that these gaps in climate knowledge have allowed a view to take hold, now enforced by rigid Net Zero political control, that CO2 is the only driver of climate change.
The Daily Sceptic recently reported on a series of media scare stories about the Greenland ice sheet that followed publication of a paper in Nature Climate Change. Cherry-picking the one-off record melt year of 2012, and assuming it will be a regular occurrence, delivered a “staggering” 78cm of sea level rise between now and 2100. According to the U.S. meteorologist Anthony Watts, the claims were “false and easily disproved”. In his view they were “just modelled hokum”.
Ice amounts around the Arctic have always been highly cyclical, with periods of substantial melt and freezing common across just a few decades. As we have seen, evidence is starting to build that a recent Arctic low point is in a period of recovery, with a significant trend towards higher surface sea ice becoming apparent from the recent data.
To preserve the fiction that humans are responsible for all recent changes in the climate, it is often argued that the current temperature is the highest for 12,000 years, since the last major ice age started to lift. This is political nonsense-on-stilts, not least because geologists have a phrase for the period when temperatures were much higher than today – the Holocene Thermal Maximum. The latest science paper to show significant higher temperatures comes from a group of geoscientists led by Dr. Katrine Elnegaard Hansen of Aarhus University. According to a précis published by the No Tricks Zone climate site, the Arctic and northern Greenland were 2-4°C warmer than now between 11,700 to 4,500 years ago. Carbon dioxide levels were in the mid 200 parts per million (ppm), compared to today’s 419 ppm, ice-free open waters prevailed, and Greenland warmed 10°C in just 60 years.
Numerous other scientists have discovered equally dramatic temperature changes in the recent past. The graph below was presented by a German broadcaster in 2013 and was compiled from a number of science sources. It shows the overall long-term trend, ending in the current small rebound from the so-called little ice age,
But cyclical changes have also occurred over very short periods. A number of scientists have pointed to an abrupt global multiple degree cooling and warming period that occurred about 8,200 years ago over 150 years. Dr. Takuro Kobashi examined the paleoclimatic records from this time and found a drop of 3°C within two decades, followed by a similar rise over 70 years. Dr. Seren Griffiths of Manchester Met University reported that the event was first identified in Greenland ice cores, but subsequently noted in multiple proxies across Europe. Another abrupt cooling period is said to have occurred about 4,000 years ago.
It is legitimate to conclude from all this under-reported science that it is becoming increasingly difficult to ask us to believe that CO2, and more specifically human-caused CO2, is the only or main climate control thermostat. The evidence suggests that the gas played no such starring role in the previous 11,000 years and more of the paleoclimatic record.
Chris Morrison is the Daily Sceptic’s Environment Editor.
Post Script: This article has been subject to various fact-checks, including this one in Agence France-Presse, this one in Reuters and this one in USA Today. Chris Morrison has responded here and here.