But let’s not forget, there was no human-produced CO2 6000-7000 years ago.
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Arctic Ocean periodically ice-free 6000 to 7000 years ago
Solar cycles, ocean currents, and volcanic heat are affecting Earth’s energy balance all the time, and always have.
Interested
1980 lies at the end-point of a well-known 30-year global cooling period which ran from about the mid-1940s to the mid-1970s.
During those three decades, some 20% of all the manmade CO2 ever produced (up to date), was emitted into the atmosphere.
Warming alarmists who maintain CO2 is the principal climate driver cannot reconcile the emission of nearly 100 gigatonnes of manmade CO2 coinciding with a corresponding period of cooling.
According to Alekseev et al. 2016 (and as you might expect after that 30 years of cooling) there was actually more Arctic sea ice in 1980 than at ANY other time during the 20th century.
So using that particular date as a starting point is useful if your aim is to accentuate the appearance of recent warming.
In any event, the Arctic ice cap is an intermittent feature. It comes and goes over millennia, and even over decades.
American nuclear submarines surfaced at an almost ice-free North Pole in 1959 and 1962. And yet by the 1999, the same region was an almost impenetrable field of sea ice.
Research into beach ridges on the northern coastline of Greenland show that 6000-7000 years ago the Arctic Ocean must have been periodically ice free all the way to the north pole for long periods of time.
But let’s not forget, there was no human-produced CO2 6000-7000 years ago.
Interestingly, according to the Danish Meteorological Institute, from 2006 to 2019 Arctic sea ice volume remained essentially constant (in fact a very slight rise may have occurred).
Once again, during this 13-year period around 20% of all the CO2 ever produced by humans was emitted into the atmosphere – and yet it had no effect on the Arctic ice cap.
So the volume of Arctic sea ice is irrelevant as far as human-induced ‘climate change’ is concerned. It comes and goes irrespective of our CO2 emissions. It’s clearly a natural variation.
Antarctic ice data is more difficult to track down but it’s understood that southern hemisphere sea ice increased strongly in the 40 years up to 2014, when it suddenly and inexplicably declined. (During that 40 years about 60% of all the CO2 ever produced by humans was emitted into the air. Yet the Antarctic sea ice grew.)
But in attempting to explain that sudden reduction in sea ice in recent years, it should be remembered that Western Antarctica and the West Antarctic Peninsula were only very recently discovered to be the home of the largest volcanic province on Earth.
In 2017 University of Edinburgh scientists identified 138 volcanoes, some as tall as 3,800 metres, buried under the ice. An increase in activity in this enormous volcanic province would doubtless be a significant factor affecting water temperature and sea ice.
So, this is why I and so many like me think it’s important that we set aside human CO2 from time to time and take a good look at the bigger picture.
Solar cycles, ocean currents, and volcanic heat are affecting Earth’s energy balance all the time, and always have.
Human influence, by comparison, is trivial and difficult even to detect.
None of the apocalyptic predictions of climate alarmism have eventuated. Not one.
The much-vaunted climate emergency therefore has no basis in science.
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July 6, 2020 at 11:24AM
Iowa Climate Science Education 