Archive for IPCC

Giant Antarctic Pine Island Glacier melting beyond point of no return

Posted in 2014 with tags , , , , , , , , , on January 15, 2014 by MARIE EMMANUELLE QUILICHINI

Antarctica’s Pine Island Glacier, one of the biggest single contributors to world sea-level rise, is melting irreversibly and could add as much as a centimetre to ocean levels in 20 years, according to a study. The glacier “has started a phase of self-sustained retreat and will irreversibly continue its decline”, said Gael Durand, a glaciologist with France’s Grenoble Alps University. Durand and an international team used three different models to forecast the glacier’s future based on the “grounding line”, which is the area under water where the ice shelf – a sea-floating extension of the continent-covering ice sheet – meets land.

This line has receded by about 10 kilometres in the past decade. The grounding line “is probably engaged in an unstable 40km retreat,” said the study, published in the journal Nature Climate Change. A massive river of ice, the glacier by itself is responsible for 20 per cent of total ice loss from the West Antarctic Ice Sheet today. On average, it shed 20 billion tonnes of ice annually from 1992-2011, a loss that is likely to increase up to and above 100 billion tonnes each year, said the study. This is equivalent to 3.5-10 millimetres of global average sea-level rise over the next 20 years.

The global mean sea level rose by 3.2mm in 2010 – itself a near-doubling from the rate of two decades earlier. The European Space Agency said last month that the West Antarctic ice sheet was shedding ice at a much faster rate than before – currently about 150 cubic kilometres a year. Climate scientists are keeping a worried eye on the mighty ice sheets of Greenland and Antarctica, as continued losses could threaten vulnerable coastal cities with dangerously high sea levels. Last year, the United Nations’ climate science body, the Intergovernmental Panel on Climate Change (IPCC) projected sea levels would rise between 26 and 82 centimetres by 2100.

Pine_Island

Solar Physicists think Sun about to enter a “grand minimum”, Chilly Conditions on Earth, The “Little Ice Age”

Posted in 2013 with tags , , , , , , , , , on October 5, 2013 by MARIE EMMANUELLE QUILICHINI

Ice-age

There’s been criticism for the Intergovernmental Panel on Climate Change (IPCC) over its latest AR5 report from many quarters for many reasons. But today there’s new research focusing on one particular aspect of that criticism.

The particular part of the IPCC’s science in question is its accounting for the effects of changes in the Sun on the climate of planet Earth. Many climatologists have long sought to suggest that the effects of solar variability are minor, certainly when compared to those of human-driven CO2 emissions. Others, however, while admitting that the Sun changes only a very little over human timescales, think that it might be an important factor.

This matters because solar physicists think that the Sun is about to enter a “grand minimum”, a prolonged period of low activity.

The current 11-year peak in solar action is the weakest seen for a long time, and it may presage a lengthy quiet period. Previously, historical records suggest that such periods have been accompanied by chilly conditions on Earth – perhaps to the point where a coming minimum might counteract or even render irrelevant humanity’s carbon emissions. The “Little Ice Age” seen from the 15th to the 19th centuries is often mentioned in this context.

READ FULL ARTICLE ON

http://www.theregister.co.uk/2013/10/01/scientists_to_ipcc_yes_solar_quiet_spells_like_the_one_now_looming_can_mean_ice_ages/

 

Sun Pillar

Sun Pillar (Photo credit: tomhe)

 

Sun Dog Phenomenon

Sun Dog Phenomenon (Photo credit: John F Hark)

 

 

 

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