Andrew Montford: Why Should Anyone Believe What Climate Models Predict?
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…