Iceberg Breakthrough Provides Hope For Improved Climate Change Models

Scientists have made a breakthrough in determining what actually causes ice shelves in the Antarctic and Greenland to break apart, resulting in icebergs and contributing to increased sea levels.

The findings, reported in the latest edition of the Science journal, could lead to improved climate change models, as scientists will now be able to predict more accurately where icebergs will “calve off” from their parent ice shelves.


Scientists have discovered the main factor to cause ice to calve away from ice sheets, creating icebergs, and resulting in higher sea levels. Photo: imon Hansen.

The term “calving” in this context, refers to ice breaking off the ice shelves and landing in the ocean, causing icebergs to form. Typically, a shelf front will extend forward for years or decades between major calving events.

Until now, the main problem for scientists was determining where an ice shelf was to calve. At what point does an ice shelf have so much ice hanging over the ocean that it starts to break off?

What made this a particularly difficult question was that, there didn’t seem to be a common size between ice shelves. For example, the Ross Ice Shelf in Antarctica hangs over the ocean for as much as 500 miles. Other ice shelves only extend for a mile or two before breaking up.
The Need For A Law For Ice Shelf Calving

To date there hasn’t been a law based on physical principles that explains ice shelf calving.

“To predict the future of the ice sheet and to understand the past, we have to put the information into a computer,” says Richard B. Alley, the Evan Pugh professor of geosciences. “The models we have do not currently have any way to figure out where the big ice sheets end and where the ice calves off to form icebergs.”

Because of this, the scientists searched for the most important variable that determines where an ice shelf will break off into the ocean - not an easy task according to professor Alley.

“Fracture-mechanics problems are invariably difficult,” he says.

“Earthquake prediction comes to mind, or guessing whether a tea cup pushed off the table will break or bounce upon hitting the floor. With the tea cup, a drop from 1 mm high won’t break it, and a drop from 100 m almost surely will — one term, the height of the drop, explains a whole lot of the behavior.” he added.

“Our hope was to find such a dominant term in calving of bergs from ice shelves.”
Simple Law for Ice Shelf Calving

The scientists believe they have found a dominant term that can be used to forecast ice shelf calving.

In the tea cup example, the height of the tea cup was the dominant term. With ice shelves, the scientists found that the spreading tendency in the direction of ice and berg motion was the dominant term.

The equation is the rate of spreading times the width of the shelf times thickness multiplied by a constant.

In other words, it is the rate at which ice shelves spread that is the most important variable that determines when an ice shelve is about to calve.

“The spreading rate can be calculated from ice thickness and a few other things that are already solved for in numerical models, so we have provided a practicable calving law,” said Alley. “At present, models rarely if ever calculate physically where the ice ends, instead stopping the model before the ice ends or using some other relation that is not fully physical.”
Global Warming

Armed with this knowledge, scientists will be in a better position to forecast the impact of global warming on sea levels.

Computer models will be able to use this information to better predict how ice sheets will behave in warmer temperatures.

Scientists recently predicted that sea temperatures would rise by over a meter by the end of this century.

Africa in danger of loosing Tourist influx due to Climatic Changes as per UN report

The haven of safaris is in danger from global warning. The coastal zones are most likely to be affected by climate change with reduced fish productivity, coral bleaching, salt water intrusion, loss of beach facilities and tourism revenues. This is as per a new report on impacts, vulnerability and adaptation in Africa , released by the data from UN bodies and the World Meteorological Organization (WMO)

Rainfall has fallen by up to 2.4% per decade in tropical rainforests regions of Africa since the mid-1970s.The rate of decline has been fastest in West Africa and north Congo. Sea levels could rise by 15 to 95 cm by 2100, according to some estimates.

It is also estimated that 30% of Africa’s coastal infrastructure could be inundated including coastal settlements in the Gulf of Guinea, Senegal, the Gambia and Egypt if Africa does not improve in climate and weather monitoring capabilities and policies. It needs 200 automatic weather stations, a genuine effort to rescue historical data and improved weather reporting capability. By 2085, between 25 per cent and over 40 per cent of species’ habitats could be lost altogether. Experts estimate that cereal crop yields will decline by up to five per cent by the 2080s.

Achim Steiner, United Nations Under-Secretary General and Executive Director of the UN Environment Programme (UNEP), said:

Climate change is underway and the international community must respond by offering well targeted assistance to those countries in the front-line which are facing increasing impacts such as extreme droughts and floods and threats to infrastructure from phenomena like rising sea levels.

All these alarming estimates are of no use if they remain as such. The need of the hour is to create concrete realities, firstly to establish better weather stations and make arrangements for greenhouse gas emissions to be cut.

Get set to visit Greenland

Intially an US Airforce base the airport at Kangerlussuaq of Greenland gives one a feeling of metal shelters. The airmen’s settlement still remains now home for employee’s at the airport and in tourism.This is the only airpot in Greenland capable of accommodating the Boeing 757s. The longest road in this country is only 12km long. Flights between cities are the answer after which come Dog-sleds and skidoos.


Greenland’s winter tourism is dependent on its snow and ice. Unfortunately Greenland ice sheet has been much effected by global warming. Temperatures have risen from 0C (32F) instead of the more usual -30C (-22F). If it were to melt global sea levels would rise by seven metres (23ft).

This land has a bleak and windswept beauty. Lake water is so clean that lake Ferguson supplies drinking water direct to the entire town. One can take a vehicle tour(Total roller coaster) to Long lake, Russell glacier and Point 660. If you are lucky you will get a glimpse of the wild life.

Mammoth dung, prehistoric goo may trigger global warming, thanks to thawing permafrost

ce thawing at the poles has been a big concern for scientists especially for the last decade - considering it a serious symptom of global warming, leaving the coastal regions at the risk of sinking under the seas and the polar animals’ going extinct.

But, the earth is actually ‘doubly suffering’ from global warming threats with the thawing of permafrost - thanks to the dramatic climate change activities.

It is the re-exposure of the mammoth dung and prehistoric goo to the air that may accelerate global warming faster than even assumed! — these being ‘organic matter’.

It was for millennia, these layers of animal waste and other organic matter have been left behind by the prehistoric creatures that romped the Arctic tundra, but were sealed inside the frozen permafrost.

But, with the changing climate, the most-happening thawing of the permafrost is leaving the prehistoric organic goo and dung exposed to air with its dormant-microbes springing back to action! - eventually adding to the already-dreading ‘carbon dioxide emissions’ and even methane gas — the even more damaging ingredient.

Thus, it seems, besides the already defined accelerators of global warming — the thought of whose devastative actions already send a chill down the spine — there are many more factors that are actually adding on to the planet’s aliment and may eventually push it to the point of no return.