The collapse in the extent of the summer minimum of Arctic Sea Ice has been a shock to everyone, but in honesty, not really a surprise. But disappearance of three-quarters-of-a-million square kilometres of sea ice seemed to be such a dramatic change that I was sure that Climate Change ‘sceptics’ would be holding up their hands and saying simply ‘I was wrong’. So I headed over to the Sea Ice Update pages of Antony Watts ‘Watts Up’ site to witness their surrender.
But far from admitting that their world view was flawed, the ‘Climate Sceptics’ were responding in a manner which would be hilarious if it were not so tragic. The discussion is a classic example of a group unable to ‘distinguish the forest from the trees’. The discussion is focussed on individual facts (the trees) which are discussed in detail and critically examined. But they denounce anyone who raises the wider context of the facts (the forest) i.e. the only theory which predicted sea-ice melting. Indeed our concerns that this might happen are the very reason that the sea-ice data exists.
The page begins with a section noting that:
…there are some quite large Sea Surface Temperature Anomalies in the Arctic at present [up to 7 °C]. They appear to centered in four primary areas, the coasts of the Beaufort, Laptev and Kara Seas, as well as the middle of Baffin Bay. There are a multitude of potential explanations for these anomalies, let’s take them individually
We then get the individual potential explanations which I will summarise:
- Could be due to the low sea ice extent which means areas previously covered with ice are now exposed.
- Could be due to an ‘unusually strong storm’ which occurred early in August which could have broken up the ice cover.
- Could be Albedo Feedback – the replacement of reflective sea ice with dark ocean – likely to be a factor.
- Could be anthropogenically-warmed river discharges – quite likely a factor in some areas.
- Could be Northern Polar Lower Troposphere Anomalies – basically the air temperature has warmed over the decades, but enough for the trend to explain the sea surface temperature anomalies.
- Could be Tundra Vegetation Feedback – where the sea ice has retreated plants have begun to grow, changing surface albedo.
I have summarised these explanations but each one is discussed in detail. The discussions then cover other possible explanations:
- Arctic Drilling
- Undersea Volcanos
- Soot from Chinese Coal Power Stations
- The effect of the North Atlantic Oscillation – a persistent weather pattern with two distinct stable states.
- Absorption of Energy from Geomagnetic Storms
- Increased use of icebreakers and even tourist boats.
- There has been no extra melting – just dispersal of sea ice into smaller pieces which are not counted as contiguous sea ice.
All these are discussed intelligently, helpfully and politely. It is an admirable example of a community of interested people discussing a topic. But when someone suggests:
There’s the increased release of anthropogenic greenhouse gases, such as CO2.
they are quickly told…
OK, you made a conjecture. Now, show a direct connection between Arctic ice melt and anthropogenic CO2, per the scientific method: testable, and using raw data. Otherwise, you have just expressed an opinion, nothing more.
In short – we don’t want to know about this.
In fact Climate models – our way of taking account of as many factors as we can think of – predicted long ago that Arctic warming would result from CO2 emissions. And Arctic warming can be reasonably expected to thin the ice sheet over the Arctic Ocean, which will then break up when there is a storm. All of the factors mentioned above may be proximate causes of the ice break up and enhanced sea-surface temperatures. But in fact the ultimate cause is in all probability the emission of greenhouse gases.
What we learn is that this group of well-meaning, interested and intelligent people simply rejected the most likely cause of this astonishing phenomenon. It caused me to wonder, if there were any event which would cause these people – not perhaps to change their minds – but to perhaps shift their opinion slightly. To consider that perhaps all the world’s experts in Climate studies might just have a point worth considering?