ENVIRONMENT: by Peter WestmoreNews Weekly
New study rebuts IPCC's rising sea-level claim
, August 6, 2011
Claims that sea levels are rising at dangerous rates, a central claim of the Intergovernmental Panel on Climate Change (IPCC), have been challenged in a new study by the New South Wales Principal Coastal Specialist, Phil Watson, after a lengthy study of century-long tidal records at several ports around Australia, published in the prestigious Journal of Coastal Research.
Mr Watson studied records from Fremantle, Western Australia (from 1897), Auckland Harbour, New Zealand (from 1903), Fort Denison in Sydney Harbour (from 1914) and the Pilot Station in Newcastle, NSW (from 1925), and found there was a “consistent trend of weak deceleration” from 1940 to 2000.
He found that sea levels had averaged a rise of just 1.7mm a year, a trend which, if continued for the rest of the 21st century, would cause a rise of about 10 cm (4 inches), which is insignificant compared to the normal tidal variation of 1 metre or more, twice a day.
In the last decade of the last century, when fears of rising sea levels were raised by the IPCC, he found that the rate of sea level rise was higher than average, but not appreciably.
He said, “They are not remarkable or unusual in the context of the historical record at each site over the 20th century.
“What we are seeing in all of the records is there are relatively high rates of sea-level rise evident post-1990, but those sorts of rates of rise have been witnessed at other times in the historical record.
“What remains unknown is whether or not these rates are going to persist into the future and indeed increase.”
He said further research was required, “to rationalise the difference between the acceleration trend evident in the global sea level time-series reconstructions (models) and the relatively consistent deceleration trend evident in the long-term Australasian tide gauge records”.
His findings parallel those published in Queensland last year.
The Tidal Reference Frame for Queensland, published by Maritime Services Queensland, is based on changes in sea levels over the 20-year period from 1990 to 2010. This is approximately the period for the solar and lunar forces which influence tides, including the earth’s distance from the sun and the moon.
The Tidal Reference is used by fishermen, port authorities and seafarers to calculate mean sea level, lowest astronomical tide, high water mark, and other information along the 3,000 km coast of Queensland, including the treacherous Great Barrier Reef.
The data show that annual sea-level rise along the Queensland coast has been consistent from the Gold Coast in the south to Thursday Island off Cape York, and averages 0.0003 metres per year. That is, 0.3mm per year.
If the trend continued for 100 years, the increase would be about 30 mm (3 cm), which is just over an inch. In contrast, the IPCC computer models predicted rises of between 50 and 80 cm this century!
Not to be outdone, the New South Wales Government’s official predictions are for a rise of 90 cm by 2100, based on CSIRO models.
However, the CSIRO projections are being challenged. Dr Howard Brady, a climate researcher at Macquarie University in New South Wales, told The Australian that sea-level rises accepted by the CSIRO were “already dead in the water as having no sound basis in probability”.
He explained: “In all cases, it is clear that sea-level rise, although occurring, has been decelerating for at least the last half of the 20th century, and so the present trend would only produce sea level rise of around 15 cm for the 21st century.”
Dr Brady said the divergence between the sea-level trends from models and sea-level trends from the tide-gauge records was now so great “it is clear there is a serious problem with the models”. He said: “In a nutshell, this factual information means the high sea-level rises used as precautionary guidelines by the CSIRO in recent years are in essence ridiculous.”
He told the ABC, “The models that have been showing acceleration in the last 15 years or so … really seem to be flawed, and then when they project their sea-level rises to 2100 it looks like these ones are now seriously out of kilter with the data that’s coming through.”
He added, “You’ve got to realise that the same answers have come up in the United States where they’ve looked at 57 tide gauges there with histories up to 160 years, and European data … and it’s all showing deceleration [in sea-level rises].”
The data also suggests that alarmist predictions that Pacific island states such as Nauru and Tuvalu will disappear into the ocean are, to say the least, premature.
United Nations predictions that by 2010 there would be 50 million climate refugees, as a result of rising sea levels, have already been shown to be alarmist nonsense.