One of the most insistent claims of the UN’s Intergovernmental Panel on Climate Change (IPCC) is that global warming is melting the world’s ice fields, causing rising sea levels which will create “climate refugees” from island-states such as Tuvalu in the Pacific and the Maldives in the Indian Ocean, and inundate low-lying coastal estuaries around the world, including countries like Bangladesh, killing millions of people.
The claims are seductive, as it is well known that sea levels have risen and fallen through the periods of the earth’s history, and atmospheric CO2 levels are rising, creating fears that this greenhouse gas will blanket the earth, melt mountain ice and the ice caps, and massively increase sea levels.
In its 2007 report, the IPCC predicted that sea levels would rise between 0.2 and 0.6 metres over the next century, based on computer models of how rising temperatures would melt the world’s ice fields.
It also claimed to have factored in the effect of the melting of sea ice around Greenland and Antarctica. It claimed further that its estimates did not account for any changes in the rate of melting of the weakened ice that flows from glaciers into the ocean. The IPCC then said that sea level rises could be higher if the ice sheets broke down more rapidly.
As if to validate the IPCC claims, a study by three American researchers, published in Science magazine in September 2008, claimed that in the 21st century, global warming would push sea levels up even more, by about 0.8 metres.
Not to be outdone, former US Vice-President Al Gore, a lawyer-turned-climate-guru, highlighted the impact of rising sea levels in his movie, An Inconvenient Truth.
As the Antarctic and Greenland ice sheets collapsed, Gore predicted, coastlines would be flooded and cities bordering the sea would sink beneath the water, leaving millions of people homeless. Gore predicted that sea levels would rise by 20 feet (over 6 metres) “in the near future”. In Australia, the Greens have happily joined the demands for action to stop rising sea levels caused by global warming.
Following release of a federal parliamentary report last October, Managing our Coastal Zone in a Changing Climate: the Time to act is Now, Greens Party leader Senator Bob Brown told reporters that a rise in sea levels would cause a big realignment of coastal housing and other buildings.
“Penny Wong herself has said that up to 700,000 properties are threatened this century by rising sea levels on the eastern Australian seaboard,” he told Melbourne’s Herald Sun. (October 27, 2009).
Greens’ climate change spokesman, Senator Christine Milne, told parliament two days later, “The government is running up the white flag on Australia’s coastline and the 711,000 residences on that coastline.
“For every metre of sea-level rise, you can talk about up to 100 metres of incursion in vulnerable coastal areas. Australians must take notice of the House of Representatives committee report but they must then come back and say to the Prime Minister and to Minister Wong, ‘You cannot look us in the eye and tell us that your targets are in any way going to mitigate this outcome’.”
She added, “If we proceed with the Carbon Pollution Reduction Scheme and a national reduction of emissions target of 5 to 25 per cent, we will lock in a high probability that we will see the worst case scenario in this report actually come to pass. That is the critical thing.”
However, the government body responsible for maritime safety in Queensland has kept records of sea level data for many years, and uses the data as the basis for marine infrastructure development, erosion monitoring, tidal predictions and safe navigation of the waters through the Great Barrier Reef.
The recently published 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.
The data shows that annual rise in sea level 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.
Over a period of 100 years, the increase would be about 30mm, which is just over an inch. Rises in sea level of this size are incomparably smaller than the daily rise and fall of the tides.
This data is incompatible with the claims made by the climate scientists, the IPCC, Al Gore, Christine Milne and Bob Brown. Whom should one believe: Maritime Services Queensland, which is responsible for the safety of coastal shipping and coastal communities, or politicians and their scientific allies who profit by climate alarmism?