Global warming latest: Amount of Antarctic sea ice hits new record high
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The levels of Antarctic sea-ice last week hit an all-time high – confounding climate change computer models which say it should be in decline.
America's National Snow And Ice Data Center, which is funded by Nasa, revealed that ice around the southern continent covers about 16million sq km, more than 2.1 million more than is usual for the time of year.
It is by far the highest level since satellite observations on which the figures depend began in 1979.
In statistical terms, the extent of the ice cover is hugely significant.
The Gerlache Strait separating the Palmer Archipelago from the Antarctic Peninsular off Anvers Island
It represents the latest stage in a trend that started ten years ago, and means that an area the size of Greenland, which would normally be open water, is now frozen.
The Antarctic surge is so big that overall, although Arctic ice has decreased, the frozen area around both poles is one million square kilometres more than the long-term average.
An adult chinstrap penguin jumps out of the sea at Port Lockroy, Antarctica
In its authoritative Fifth Assessment Report released last year, the UN Intergovernmental Panel on Climate Change admitted that the computer models on which scientists base their projections say Antarctic ice should be in decline, not increasing.
The report said: 'There is low confidence in the scientific understanding of the observed increase in Antarctic sea ice extent since 1979, due to… incomplete and competing scientific explanations for the causes of change.'
Some scientists have suggested the Antarctic ice increase may itself be caused by global warming. But Professor Judith Curry, head of climate science at the Georgia Institute of Technology in Atlanta, said the arguments were not convincing.
She added: 'We do not have a quantitative, predictive understanding of the rise in Antarctic sea ice extent.' She said it was becoming increasingly apparent that long-term cycles in ocean temperatures were responsible for a significant proportion of the ice decline in the Arctic – a process that may be starting to reverse.
Prof Curry also revealed that because of the 'pause', in which world average temperatures have not risen for more than 16 years, the Arctic ice decline has been 'touted' by many as the most important evidence for continued global warming.
A Crabeater seal on an iceberg in Paradise Bay, Antarctica. Crabeater seals are the most common large mammal on the planet after humans, with an estimated population of 15 million
The Gerlache Strait separating the Palmer Archipelago from the Antarctic Peninsular off Anvers Island
But in her view, climate scientists have to consider evidence from both Poles.
She added: 'Convincing arguments regarding the causes of sea-ice variations require understanding and ability to model both the Arctic and Antarctic.'
IT'S POLITICS, NOT SCIENCE, DRIVING CLIMATE CHANGE MANIA
For years, computer simulations have predicted that sea ice should be disappearing from the Poles.
Now, with the news that Antarctic sea-ice levels have hit new highs, comes yet another mishap to tarnish the credibility of climate science.
Climatologists base their doom-laden predictions of the Earth's climate on computer simulations.
But these have long been the subject of ridicule because of their stunning failure to predict the pause in warming – nearly 18 years long on some measures – since the turn of the last century.
It's the same with sea ice. We hear a great deal about the decline in Arctic sea ice, in line with or even ahead of predictions.
But why are environmentalists and scientists so much less keen to discuss the long-term increase in the southern hemisphere?
In fact, across the globe, there are about one million square kilometres more sea ice than 35 years ago, which is when satellite measurements began.
It's fair to say that this has been something of an embarrassment for climate modellers. But it doesn't stop there.
In recent days a new scandal over the integrity of temperature data has emerged, this time in America, where it has been revealed as much as 40 per cent of temperature data there are not real thermometer readings.
Many temperature stations have closed, but rather than stop recording data from these posts, the authorities have taken the remarkable step of 'estimating' temperatures based on the records of surrounding stations.
So vast swathes of the data are actually from 'zombie' stations that have long since disappeared.
This is bad enough, but it has also been discovered that the US's National Oceanic and Atmospheric Administration is using estimates even when perfectly good raw data is available to it – and that it has adjusted historical records.
Why should it do this?
Many have noted that the effect of all these changes is to produce a warmer present and a colder past, with the net result being the impression of much faster warming. They draw their conclusions accordingly.
Naturally, if the US temperature records are indeed found to have been manipulated, this is unlikely to greatly affect our overall picture of rising temperatures at the end of the last century and a standstill thereafter.
The US is, after all, only a small proportion of the globe.
Similarly, climatologists' difficulties with the sea ice may be of little scientific significance in the greater scheme of things.
We have only a few decades of data, and in climate terms this is probably too short to demonstrate that either the Antarctic increase or the Arctic decrease is anything other than natural variability.
But the relentless focus by activist scientists on the Arctic decline does suggest a political imperative rather than a scientific one – and when put together with the story of the US temperature records, it's hard to avoid the impression that what the public is being told is less than the unvarnished truth.
As their credulity is stretched more and more, the public will – quite rightly – treat demands for action with increasing caution…
Andrew Mountford
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