Update: 27th August 2012, arctic sea ice extent is now a record low.
This year is breaking all records for the melting of the Arctic ice (see Arctic Sea Ice News ). Read to the end of the article below if you want the scary stuff.
The white areas have at least 15% ice - they do not represent continuous ice. Here is a comparison with previous years:
This year will almost certainly be a record low. The European Space Agency's Cryosat-2 satellite has recently shown that the ice has become much thinner than expected and ready to go. This is a corollary of the decline in the age of the sea ice:
The white area on the right probably marks what will be left of the North Polar Ice Cap in a few years.
Now for the scary stuff. If the arctic ice melts this will cause a sudden spike of global warming because of changes in albedo. The "albedo" of the earth is the proportion of sunlight that is reflected back into space. If the albedo is 0.5 then half of the sunlight is reflected, if it is 0.1 then only 10% is reflected. NASA says that:
"A drop of as little as 0.01 in Earth’s albedo would have a major warming influence on climate—roughly equal to the effect of doubling the amount of carbon dioxide in the atmosphere, which would cause Earth to retain an additional 3.4 watts of energy for every square meter of surface area." NASA: Earth's Albedo in Decline
The Arctic News Blog provides an in depth analysis of the albedo and sea ice changes. In the Arctic News blog there is a graphic that shows sea ice volume rather than area:
This graphic is in line with the Cryosat-2 results showing that the ice is thinning rapidly. It suggests that the arctic will be ice free in the summer of 2014. The albedo of open sea (0.1) is much less than that of ice and snow (0.6). How will the change in albedo affect the climate?
The average ice cover will fall from about 10 million square kilometres to 6 million square kilometres. A fall of about 4 million square kilometres. The angle presented by the poles to the sun over the whole day is only about 60% of the average angle over the whole earth. The albedo change (0.5) as a fraction of the whole earth's albedo will be: (0.5 x 0.6 x 4) / 510 = 1.2 /510 = 0.0024. Taking the NASA figure of 3.4 Watts per square metre for each 0.01 change in albedo, the albedo change due to the melting arctic would change solar irradiance by about 0.8 Watts per square metre. If we include the loss in snow cover of surrounding land we can probably double this figure to 1.5 W per sq m. This is roughly equal to the entire heating effect of all the anthropogenic influences on climate (1.6 W per sq m). (This calculation was loosely based on that given at http://arctic-news.blogspot.co.uk/2012/07/albedo-change-in-arctic.html ).
Most of the burden of warming due to the fall in albedo will occur in the arctic. We can probably expect a rapid melting of the permafrost in the north. This will release carbon from organic material that has been entombed in the ice for millennia.
If the permafrost melts then we are indeed in trouble, the graphic above is a prediction of the amount of carbon released by melting permafrost (based on the arctic being ice free in summer in about 2100). If the arctic becomes ice free by 2015 in the summer then the peak of the graphic above would probably shift back by decades.
The permafrost melt will release a lot of methane. Methane is much worse than CO2 for creating global warming.
This all looks more than a little disturbing. But don't let anyone suggest geo-engineering as a solution, it isn't. Remember, the engineers said it was safe to build nuclear reactors on earthquake faults in Japan and the media said that global warming was not really happening - don't believe them if they say geo-engineering will fix everything. The source of all of these problems is overpopulation but no political leader is prepared to face up to this reality.
Incidentally, there is a very strange rumour circulating that the arctic had as little ice as today in 1938. Here is an official picture of the August 1938 extent:
There are lies out there. Here is a graphic to show that the current decline is exceptional:
See also:
The Evidence for Global Warming. (1) the Himalayas
The Evidence for Global Warming. (2) Analysis using source data for global changes
Global warming (3) man or nature?
The strange case of the missing CO2
Is climate change a threat because of overpopulation?
Blue Haze, Brown Clouds and the need to stop Geoengineering before it begins.
Global warming: what do we do now?
This year is breaking all records for the melting of the Arctic ice (see Arctic Sea Ice News ). Read to the end of the article below if you want the scary stuff.
The white areas have at least 15% ice - they do not represent continuous ice. Here is a comparison with previous years:
 |
| Image from Rutgers University Northern Hemisphere Snow and Ice Climate Data Records http://climate.rutgers.edu/measures/snowice/?q=projects |
Now for the scary stuff. If the arctic ice melts this will cause a sudden spike of global warming because of changes in albedo. The "albedo" of the earth is the proportion of sunlight that is reflected back into space. If the albedo is 0.5 then half of the sunlight is reflected, if it is 0.1 then only 10% is reflected. NASA says that:
"A drop of as little as 0.01 in Earth’s albedo would have a major warming influence on climate—roughly equal to the effect of doubling the amount of carbon dioxide in the atmosphere, which would cause Earth to retain an additional 3.4 watts of energy for every square meter of surface area." NASA: Earth's Albedo in Decline
The Arctic News Blog provides an in depth analysis of the albedo and sea ice changes. In the Arctic News blog there is a graphic that shows sea ice volume rather than area:
 |
| Graphic from Arctic News Blog: http://arctic-news.blogspot.co.uk/2012/07/albedo-change-in-arctic.html |
The average ice cover will fall from about 10 million square kilometres to 6 million square kilometres. A fall of about 4 million square kilometres. The angle presented by the poles to the sun over the whole day is only about 60% of the average angle over the whole earth. The albedo change (0.5) as a fraction of the whole earth's albedo will be: (0.5 x 0.6 x 4) / 510 = 1.2 /510 = 0.0024. Taking the NASA figure of 3.4 Watts per square metre for each 0.01 change in albedo, the albedo change due to the melting arctic would change solar irradiance by about 0.8 Watts per square metre. If we include the loss in snow cover of surrounding land we can probably double this figure to 1.5 W per sq m. This is roughly equal to the entire heating effect of all the anthropogenic influences on climate (1.6 W per sq m). (This calculation was loosely based on that given at http://arctic-news.blogspot.co.uk/2012/07/albedo-change-in-arctic.html ).
Most of the burden of warming due to the fall in albedo will occur in the arctic. We can probably expect a rapid melting of the permafrost in the north. This will release carbon from organic material that has been entombed in the ice for millennia.
If the permafrost melts then we are indeed in trouble, the graphic above is a prediction of the amount of carbon released by melting permafrost (based on the arctic being ice free in summer in about 2100). If the arctic becomes ice free by 2015 in the summer then the peak of the graphic above would probably shift back by decades.
The permafrost melt will release a lot of methane. Methane is much worse than CO2 for creating global warming.
 |
| The average atmospheric concentration of methane shot up suddenly in 2007, having remained stable for a decade. Data shown are from the Advanced Global Atmospheric Gases Experiment and the Australian Commonwealth Scientific and Industrial Research Organisation, courtesy of Matt Rigby. |
Incidentally, there is a very strange rumour circulating that the arctic had as little ice as today in 1938. Here is an official picture of the August 1938 extent:
There are lies out there. Here is a graphic to show that the current decline is exceptional:
See also:
The Evidence for Global Warming. (1) the Himalayas
The Evidence for Global Warming. (2) Analysis using source data for global changes
Global warming (3) man or nature?
The strange case of the missing CO2
Is climate change a threat because of overpopulation?
Blue Haze, Brown Clouds and the need to stop Geoengineering before it begins.
Global warming: what do we do now?
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