Greenland is melting at incredible rate

The combination-image below shows how much the ice on Greenland melted between July 8 (left) and July 12 (right).

On July 8, about 40% of the ice sheet had undergone thawing at or near the surface. In just a few days, the melting had dramatically accelerated and some 97% of the ice sheet surface had thawed by July 12. 

In the image, the areas classified as “probable melt” (light pink) correspond to those sites where at least one satellite detected surface melting. The areas classified as “melt” (dark pink) correspond to sites where two or three satellites detected surface melting. The satellites are measuring different physical properties at different scales and are passing over Greenland at different times. Credit: Nicolo E. DiGirolamo, SSAI/NASA GSFC, and Jesse Allen, NASA Earth Observatory.

For several days this month, Greenland's surface ice cover melted over a larger area than at any time in more than 30 years of satellite observations. Nearly the entire ice cover of Greenland, from its thin, low-lying coastal edges to its two-mile-thick center, experienced some degree of melting at its surface, according to measurements from three independent satellites analyzed by NASA and university scientists.

On average in the summer, about half of the surface of Greenland's ice sheet naturally melts. At high elevations, most of that melt water quickly refreezes in place. Near the coast, some of the melt water is retained by the ice sheet and the rest is lost to the ocean. But this year the extent of ice melting at or near the surface jumped dramatically. According to satellite data, an estimated 97% of the ice sheet surface thawed at some point in mid-July.

This extreme melt event coincided with an unusually strong ridge of warm air, or a heat dome, over Greenland. The ridge was one of a series that has dominated Greenland's weather since the end of May. "Each successive ridge has been stronger than the previous one," said Mote. This latest heat dome started to move over Greenland on July 8, and then parked itself over the ice sheet about three days later. By July 16, it had begun to dissipate.

As the ice warms, it loses albedo, i.e. less sunlight is reflected back into space. Darker surface absorbs more sunlight, accelerating the melting. The image below shows the Greenland ice sheet albedo from 2000 to 2011.

Credit: NOAA Arctic Report Card 2011.

The image below, from the meltfactor blog and by Jason Box and David Decker, shows the steep fall in reflectivity for altitudes up to 3200 meters in July 2012. 

The image below, from the meltfactor blog, shows how the year 2012 compares with the situation at approximately the same time in previous years, 2011 and 2010, which are recognized as being record melt years. 

The photo below shows how dark the ice sheet surface can become.

Photo shot by Jason Box on August 12, 2005

Loss of albedo occurs as the darker bare ground becomes visible where the ice has melted away. Darkening of snow and ice can start even before melting takes place. Warming changes the shape and size of the ice crystals in the snowpack, as described at this NASA Earth Observatory page. As temperatures rise, snow grains clump together and reflect less light than the many-faceted, smaller crystals. Additional heat rounds the sharp edges of the crystals, and round particles absorb more sunlight than jagged ones. 

Dirty ice surrounds a meltwater stream near the margin of the ice sheet. Compared to fresh snow and clean ice, the dark surface absorbs more sunlight, accelerating melting. © Henrik Egede Lassen/Alpha Film, from the Snow, Water, Ice, and Permafrost in the Arctic report from the U.N. Arctic Monitoring and Assessment Programme. From NOAA Climatewatch.

Another factor contributing to darkening is aerosols, in particular soot (i.e. black carbon) from fires and combustion of fuel, dust and organic compounds that enter the atmosphere and that can travel over long distances and settle on ice and snow in the Arctic. 

The July data since 2000, from the meltfactor blog, suggest a exponential fall in reflectivity that, when projected into the future (red line, added by Sam Carana), looks set to go into freefall next year. 

Is a similar thing happening all over the Arctic? Well, the map below, edited from a recent SSMIS Sea Ice Map, shows that sea ice concentration is highest around the North Pole. 

So, can water be expected to show up at the North Pole? Well have a look at the photo from the North Pole webcam below. 

Photo from the North Pole webcam

It does look like melting is going on at the North Pole. Water is significantly darker than ice, meaning the overall reflectivity will be substantially lowered by this water. 

It's important to realize that surface albedo change is just one out of a number of feedbacks, each of which deserves a closer look. 

As shown on the image below, the IPCC describes four types of feedbacks with a joint Radiative Forcing of about 2 W/sq m, i.e. water vapor, cloud, surface albedo and lapse rate. 

The image below, from James Hansen et al., may at first glance give the impression that all aerosols have a cooling effect. 

When components are split out further, it becomes clear though that some aerosols are reflective and have a cooling effect, whereas black carbon has a warming effect, while changes in snow albedo also contribute to warming. On the interactive graph below, you can click on or hover over each component to view their radiative forcing. When isolated from other factors, it's clear that snow albedo has an increasing warming effect.
How much could Earth warm up due to decline of snow and ice? Professor Peter Wadhams estimates that the drop in albedo in case of total loss of Arctic sea ice would be a 1.3 W/sq m rise in radiative forcing globally, while additional decline of ice and snow on land could push the the combined impact well over 2 W/sq m.

Locally, the impact could be even more dramatic. The image below, from Flanner et al., shows how much the snow and ice is cooling the Arctic. 

Image, edited by Sam Carana, from Mark Flanner et al. (2011).

Conversely, above image shows how much the Arctic could warm up without the snow and ice. Due to albedo change, sunlight that was previously reflected back into space will instead warm up the Arctic. What could have a big impact locally is that, where there's no more sea ice left, all the heat that previously went into melting will raise temperatures instead, as described at Warming in the Arctic.

The big danger is methane. Drew Shindell et al. show in Improved Attribution of Climate Forcing to Emissions that inclusion of aerosol responses will give methane a much higher global warming potential (GWP) than the IPCC gave methane in AR4, adding that methane's GWP would likely be further increased by including ecosystem responses. Indeed, as pictured in the image below, accelerated warming in the Arctic could trigger methane releases which could cause further methane releases, escalating into runaway global warming. 

Runaway Global Warming

If you like, you can order prints of above image at Shutterfly (8 x 10 size works best).

How to part ways with a climate denier that has incredible stamina...

Paul Beckwith, with other scientists in Ottawa
protesting against the "Death of Evidence"

By Paul Beckwith,

On a Canadian chess blog (chesstalk.com) there is a thread called “The NEW One and Only Climate Change Whatever” that has been ongoing for over two years. Basically, I educate the chess community on climate change and many chess players that are rabid deniers gang up and hurl invective and deny fervently. A waste of time for me? Perhaps? Likely not, since it has hardened my resolve and energized me in my climate change study/research/lobbying/etc. etc. In fact, now I generally have great fun at hurling invective back until it starts to get out of hand. Then it is no longer fun or useful so I part-ways with the person, as happened tonight…


Mr/Mrs. XXXXX,

It used to bother me when people such as yourself that know absolutely squat about climate change (a subject in which I am an expert and forever striving to increase that expertise) make claims that are completely without scientific merit, in fact that are downright wrong, quite often intentionally wrong. Why? In most subjects this would not matter. Not so with climate change. Because our climate is collapsing around us and there are still many many people that fail to see this. So humanity will not act, and it will get worse and worse until there will not be a single person on the planet that does not experience gut-wrenching change. People are dying now, and will be dying in ever greater numbers from the near-term changes that are underway. Massive crop failure in the U.S. this year will not starve people in North America but will stress the economy and pocketbooks of many residents. It will starve people already in poverty who pay 25% or 50% of their incomes on food now. North Americans will not panic over one year of crop failure. However if it happens the following year, and the one after that, and after that then the system will snap.

Climate denialism and such nonsense no longer bothers me because I have learned how to deal with such people and views. As is absolutely required for anyone in the field of climatology. How? I initially take the time to explain some science and educate but when it is clear that I am dealing with an immovable object like yourself or yyyyy I just have some fun with it and hurl a few insults, etc. However this gets old and distracting and unproductive very quickly and wastes a lot of time. As it has now, in your case.

It no longer bothers me because our planet is now committed to this gut-wrenching change. The sea ice will be gone very soon and the roller coaster ride will be unstoppable. If I was Obama or Putin or any other world leader I would declare "War on Warming", cool the Arctic with geoengineering to keep the sea ice intact and the methane in the ground and undergo a crash program to slash emissions. But I am not. So I do what I can to educate people/inform them/get the word out. I join organizations like AMEG (Arctic Methane Emergency Group). I meet with politicians at all levels of government and talk about the urgency of climate change and necessity of rapidly cooling the Arctic. I have a clear conscience because I have tried. I know that many people around the world will die, I know that unbelievable changes are starting to occur and will explode in frequency, amplitude, spatial extent and impact over this decade, and I know that the general public will be in shock when their familiar climate system becomes a complete stranger to them...Personally, as I have acquired more and more knowledge over the course of my Ph.D. studies in abrupt climate change, I have passed through the shock stage, and the subsequent unaccepting stage of grief a long time ago, I am in the acceptance stage now.

Apologies, it was a blast to hurl invective back and forth, but I am not playing that game anymore. I will not be reading ANY of your posts on this thread, for a while anyway. I need a XXXXX break.

P.S. I did not take the time to write this post just for your sake alone. I am posting it, with your name removed, in social media under the heading "How to part ways with a climate denier that has incredible stamina . . .". Thanks for the learning experience.

How extreme will it get?

The January-June period was the warmest first half of any year on record for the contiguous United States, reports NOAA in its June 2012 overview. The national temperature of 52.9°F was 4.5°F (2.5°C) above average. 

The United States Department of Agriculture has designated 1,016 primary counties in 26 states as natural disaster areas, making it the largest natural disaster in America ever.  

The U.S. Drought Monitor has declared 80% of the Contiguous U.S. to be abnormally dry or worse, with 61% experiencing drought conditions ranging from moderate to exceptional—the largest percentage in the 12-year history of the service.  

In the 18 primary corn-growing states, 30% of the crop is in poor or very poor condition. In addition, fully half of the nation’s pastures and ranges are in poor or very poor condition. The year-to-date acreage burned by wildfires has increased to 3.1 million. 

NOAA reports record temperatures in many places; in Mc Cook, Neb., it was 115°F (46°C) on June 26, while in Norton Dam, Kan., it was 118°F (48°C) on June 28. Meanwhile, it was 126°F (52°C) in Death Valley National Park on July 10, 2012.

Lake Michigan surface water temperatures recently reached temperatures of up to 83.9°F (29°C), as shown on the image right. Lake Michigan has a surface area of 22,400 square miles (58,000 square kilometers). The lake's average depth is 279 ft (85 m), while its greatest depth is 923 ft (281 m). The image below compares 2012 surface water temperature with the average for 1992-2011.

Earlier this year, in March 2012, another heatwave hit much the same area. A NOAA analysis of the heatwave notes the abrupt onset of the warmth at Minneapolis, Duluth, and International Falls on 10 March. On subsequent days, anomalies of well over 20°C (36°F) were recorded as shown on the image on the right.

Temperature anomalies of 27+°F (15+°C) were recorded in a large area from March 12th to March 23rd, 2012, as shown below. 

 

Global warming is responsible for much of the frequency and intensity of extreme weather events and this is linked to developments in the Arctic, where accelerated warming is changing the jet stream, concludes an analysis by Rutgers University professor Jennifer Francis.

Apart from the obvious impact that droughts and heatwaves have on food and fresh water supply, they also come with wildfires that cause additional emissions, constituting a further positive feedback that further contributes to global warming, while the additional soot makes things even worse in the Arctic.

All this combines to create a situation in the Arctic where extreme local warming events can trigger methane releases, causing further local warming and further releases of methane, in a vicious cycle that threatens to escalate into runaway global warming that feeds on itself.  

The above image pictures the three kinds of warming (red lines) and their main causes:

1. Emissions by people cause global warming, with temperatures rising around the globe, including the Arctic.
2. Soot, dust and volatile organic compounds settle down on snow and ice, causing albedo change. More heat is absorbed, rather than reflected as was previously the case. This causes accelerated warming in the Arctic.
3. Accelerated warming in the Arctic threatens to weaken methane stores in the Arctic with the danger that releases will cause runaway global warming.
   
   

In addition, there are at least three feedback effects (gold lines) that make things even worse:

• Fires feedback: Accelerated warming in the Arctic is changing the Jet Stream, contributing to increased frequency and intensity of droughts and heatwaves.
• Albedo feedback: Accelerated warming in the Arctic also speeds up the decline of ice and snow cover, further accelerating albedo change.
• Methane feedback: Methane releases in the Arctic further add to the acceleration of warming in the Arctic, further contributing to weaken Arctic methane stores, in a vicious cycle that threatens to escalate into runaway global warming.

Rapid warming periods in the past constitute an ominous warning. In a paper published about a year ago, Ruhl et al. conclude that the end-Triassic mass extinction, about 200 million years ago, started with global warming due to carbon dioxide from volcanoes. This also caused warming of oceans and melting of hydrates at the bottom of the sea, containing methane created by millions of years of decomposing sea life. The hydrates released some 12,000 gigatons of methane, causing global warming to accelerate and resulting in sudden extinction of about half the species on Earth at the time.

The above image pictures how a similar thing could happen in our times, with global warming leading to accelerated warming in the Arctic, triggering hydrate destabilization and abrupt release of, say, 1 Gt of methane, which would further accelerate Arctic warming and lead to subsequent releases of methane from hydrates.

For more details on above two graphs, see the page How much time is there left to act?

Could extreme weather, like the U.S. is now experiencing, also occur in the Arctic?

Well, it actually did, not too long ago. Above image on the right, from the Cryosphere Today, shows air temperature anomalies in the Arctic of up to 6°C (10.8°F) for the month September 2007.

By how much will the sea warm up during such extreme local warming events?

The image on the right, produced with NOAA data, shows mean coastal sea surface temperatures of over 10°C (50°F) in some areas in the Arctic on August 22, 2007.

How extreme was this?

The image below, from NOAA, shows that sea surface temperature anomalies of over 5.5 were recorded for August 2007 in some areas in the Arctic.



Could such warming reach the bottom of the sea?

Again, this did happen in 2007, when strong polynya activity caused more summertime open water in the Laptev Sea, in turn causing more vertical mixing of the water column during storms in late 2007, according to one study, and bottom water temperatures on the mid-shelf increased by more than 3°C (5.4°F) compared to the long-term mean.

Another study finds that drastic sea ice shrinkage causes increase in storm activities and deepening of the wind-wave-mixing layer down to depth ~50 m (164 ft) that enhance methane release from the water column to the atmosphere. Indeed, the danger is that heat will warm up sediments under the sea, containing methane in hydrates and as free gas, causing large amounts of this methane to escape rather abruptly into the atmosphere.

Would this heat be able to penetrate sediments?

The image on the right, from a study by Hovland et al., shows that hydrates can exist at the end of conduits in the sediment, formed when methane did escape from such hydrates in the past. Heat can travel down such conduits relatively fast, warming up the hydrates and destabilizing them in the process, which can result in huge abrupt releases of methane.

Since waters can be very shallow in the Arctic, much of the methane can rise up through these waters without getting oxidized.

Shakova and Semiletov warn, in a 2010 presentation, that some 75% of the East Siberian Arctic Shelf (ESAS) is shallower than 50 m, as shown on the image below. Furthermore, the ESAS region alone has an accumulated methane potential of some 1700 Gt in the form of free gas and hydrates under the sediment, in addition to organic carbon in its permafrost.

As the methane causes further warming in the atmosphere, this will contribute to the danger of even further methane escaping, further accelerating local warming, in a vicious cycle that can lead to catastrophic conditions well beyond the Arctic.

Above image shows the carbon in the melting permafrost, estimated by Schuur et al. at 1700 Gt. Much of this carbon could also be released as methane under warmer and wetter conditions.

Under warmer and dry conditions, things wouldn't be much better. The 2010 heatwave in Russia provides a gloomy preview of what could happen as temperatures rise at high latitudes. Firestorms in the peat-lands, tundras and forests in Siberia could release huge amounts of emissions, including soot, much of which could settle on the ice in the Himalaya Tibetan plateau, melting the glaciers there and causing short-term flooding, followed by rapid decline of the flow of ten of Asia's largest river systems that originate there, with more than a billion people's livelihoods depending on the continued flow of this water.