Photo shows melting ice in Greenland.
THE Arctic Ocean ice sheet first began to form approximately three million years ago, but actually it has never been thicker than three metres, as a rule.
There are exceptions where the ice is crushed down to a depth of 30 metres. Glaciologists have separated the ice there into three categories; older ice (more than two years old), second year ice (one to two years old) and first year ice (less than one year).
The first category obviously has lasted longer than its summer’s thawing. Since 1979, glaciologists have been keeping an eagle eye on the speed at which the overall ice cover has been shrinking during the Arctic summer months. Up until 2000 a small area gradually melted, but since the Millennium Year – now only 17 years ago – the area of older ice has shrunk rapidly.
Continuously, during the three summer months of 2005 to 2007, some 20 per cent of the Arctic ice sheet has melted but this was recouped in the winter months with the maximum of the ice sheet extent reaching an all-time record. That said, the Arctic ice sheets are thinning fast through melting, thus releasing stored CO2 into the sea and acidifying the waters. Ice is a great absorber of atmospheric carbon dioxide. During the period 2007 to 2008, the depth of the sea ice had slimmed down to only two metres and less.
The Greenland icecap
This land-based icecap, as opposed to the Arctic Ocean ice, is also melting at a vast rate, exposing more and more land beneath it. It has been a very deep icecap, compressing the land beneath it so, as it melts, isostatic equilibrium comes into play and the land rises, creating raised beaches. It’s a bit like falling on a foam mattress and then jumping off.
The effects of this have already been seen in the local activities and economies of the Inuit people, who have been deprived of their daily survival in their fish and seal hunting expeditions.
During June’s conference of the International Panel on Climate Change (IPCC) in Paris, it was revealed that our ocean levels have risen 50 per cent faster in 2014 than in the 20 years previously. Meltwater from the Greenland icecap is now found to supply 25 per cent of the total rise in ocean levels compared with 5 per cent only 20 years earlier.
Greenland contains enough potential ice melt to lift our worldwide sea levels by seven metres. Clearly alarm bells are beginning to ring, for it is thought that the current loss of ice from the Arctic, Greenland and west Antarctica’s Ross Shelf is still increasing and, indeed, increasing exponentially. Overall, the average rate of sea level rise increased from 2.2 millimetres a year in 1994 to 3.3 millimetres in 2014. As a result of global warming, thermal expansion in sea water occurs, and in the 1990s this accounted for 50 per cent of all millimetre added rises. In 2010 this dropped to 30 per cent, with the other 70 per cent attributed to glacial meltwater.
Tracing ice loss
Satellite imagery over time does add an extra dimension in the 21st century. In 2010, meteorologists at the British Meteorological Office in Exeter began to research ships’ logbooks that had been collecting dust at the National Archives in Kew, London. They have found a wealth of information as to the extent of the edges of the Arctic ice sheet, dating back to the 1850s. This was at the time that the American author, Herman Melville, published his classic novel ‘Moby Dick: The Whale’. Few will know that Melville’s knowledge of whaling was personally based, for in the 1840s he had joined the crew of a whaling ship venturing as far south as Antarctica.
These whalers’ logbooks are the only records we have of the extent of the Arctic ice in the 1800s, when whalers recorded not only their passages through ice packs, but where they got stuck in the ice and where they congregated as fleets on the edges of the ice.
Today, most oceanographers agree that there is an expected rise in sea level to be well over a metre by the end of our present century. As the sea water heats up from underneath, it meets the floating ice above.
This ice is fed by glaciers moving down from above and thus floating on the denser sea water. With melting occurring at the snouts of these glaciers, to restore equilibrium the glaciers accelerate, leading to further melting in the seas and the further loss of overall ice thickness on a landmass such as Greenland or Antarctica.
A global flood?
This is not as ridiculous as it may seem with the continuous increase in height of our sea levels. Currently there are over 50 million people living in locations prone to storm surges. A rise in sea level by only 0.5 metres would double that number.
A metre rise would see 20 per cent of Bangladesh under water and 6 per cent of the Netherlands. Floods would occur in the USA from Boston to Florida and New Orleans would be entirely wiped out. How many of our cities and other major urban areas are built just a few metres or less above present sea levels?
What effects would a rise of one metre have upon Kuching, Kota Kinabalu, Miri and Sandakan? Many tourist ‘beehives’ and coastal resorts would be destroyed and islands swamped. The scale of devastation might be in dispute, but there is no doubt that sea levels are rising.
Indian flood victims wade through flood waters to collect relief materials in Chitnan village, west of Kolkata last month. – AFP file photo
Future planning
Locally and worldwide, planners, architects and prospective builders of residential and commercial developments need to take aboard (not meant as a pun) the increasing rise of sea levels. While, money may be made in speculative additions to urban areas in lowland areas for immediate gain, we need to think down the timeline. In 70 years’ time such developments will be flooded out.
Dam builders need to dredge their reservoirs regularly, for dams are man-made silt traps. Silt, when naturally washed by free flowing rivers to the sea, is a land builder which helps break the force of cyclonic storm-generated waves.
Already, island nations such as the Seychelles, the Maldives and Mauritius are crying aloud for the present and near future of their loss of incomes from tourism as their coastal beaches are slowly disappearing under water. Current wetland nature reserves for birds will vanish to marine life.
We need to think about this problem of rising sea levels today. I am not a prophet of doom and gloom, but a realist, for tomorrow may be too late.
Pro-action is more beneficial to mankind than reaction after a foreseeable disaster has occurred. Hindsight helps few people in their losses.