Warming in the Arctic is accelerating. On June 25, 2015, high temperatures hit North America. Temperatures as high as 30.3°C (86.54°F) were recorded where the Mackenzie River is flowing into the Arctic Ocean.
June 25, 2015 - High temperatures over North America, close to the Arctic Ocean
On July 1, 2015, temperatures are forecast to be as high as 111.4°F (or 44.1°C) near Chico, north of San Francisco. Temperatures are forecast to be high over most of North America and Eastern Siberia, threatening to further warm up waters of the Arctic Ocean.
Forecast for July 1, 2015 - High temperatures over North America, close to the Arctic Ocean
The image below shows that on June 27, 2015, temperatures of well over 40°C (104°F) were recorded in Europe and in Pakistan, where temperatures earlier this month had reached 49°C (120.2°F) in some places. The heat wave reportedly killed 1233 people in Karachi alone. This in addition to the 2500 people killed earlier in India by high temperatures.
June 27, 2015 - High temperatures over Russia, close to the Arctic Ocean
High temperatures at such locations are very worrying, for a number of reasons, including:
They are examples of heatwaves that can increasingly extend far to the north, all the way into the Arctic Ocean, speeding up warming of the Arctic Ocean seabed and threatening to unleash huge methane eruptions.
They set the scene for wildfires that emit not only greenhouse gases such as carbon dioxide and methane, but also pollutants such as carbon monoxide (that depletes hydroxyl that could otherwise break down methane) and black carbon (that when settling on ice causes it to absorb more sunlight).
They cause warming of the water of rivers that end up in the Arctic Ocean, thus resulting in additional sea ice decline and warming of the Arctic Ocean seabed.
June 24, 2015 - Smoke from wildfires in Alaska - from: wunderground.com
The image below shows increased sea surface temperature anomalies in the Arctic. Note the warming in the area of the Beaufort Sea where the Mackenzie River is flowing into the Arctic Ocean.
Very warm water is also flowing from the Pacific Ocean through the Bering Strait into the Arctic Ocean. As the image below shows, the water that is flowing into the Arctic Ocean from the Pacific is much warmer than it used to be, as much as 6.1°C (10.98°F) warmer.
View the flow of the water on the animated version of above image at earth.nullschool.net
As said above, warm water flowing from rivers into the Arctic Ocean is a major contributor to these sea surface temperature anomalies. As also illustrated by the NOAA image below, rivers carrying warm water into the Bering Strait include the Kobuk River, the Naotak River and the Yukon River that flows all the way from British Columbia, Canada, through Alaska and ends in the Bering Strait. Sea surface temperatures near the coast of Alaska were as high as 19°C (66.2°F) from June 21-24, 2015.
Sea surface temperatures near the coast of Alaska as high as 19°C (66.2°F) from June 21-24, 2015
The Naval Research Laboratory animation below shows changes to Arctic sea ice thickness. Sea ice thickness (in m) down to zero where the Mackenzie River flows into the Arctic Ocean and in the Bering Strait where warm water from the Pacific is entering the Arctic Ocean.
The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan.
Sea surface temperature anomalies in the Arctic. Note the warming in the area of the Beaufort Sea where the Mackenzie... Posted by Sam Carana on Thursday, June 25, 2015
A thick layer of smoke blankets large parts of North America, as also illustrated by the animation below based on images from July 15 to 18, 2014, from Wunderground.com.
[ note that this animation is a 2.3MB file that may take some time to fully load ]
Such wildfires can send huge amounts of carbon dioxide, methane, soot, dust and volatile organic compounds into the atmosphere. Much of this gets deposited at higher latitudes, discoloring land, snow and ice, and thus speeding up warming by absorbing more sunlight that was previously reflected back into space.
Soils at higher latitudes can contain huge amounts of carbon in the form of peat, as described in the earlier post The Threat of Wildfires in the North. There are further conditions that make the situation in the Arctic so dangerous.
Temperature anomaly March-April-May-June 2014 (JMA)
The Arctic is particularly vulnerable to warming due to geographics. Seas in the Arctic Ocean are often shallow and covered by sea ice that is disappearing rapidly. Largely surrounded by land that is also rapidly losing its snow and ice cover, the Arctic Ocean acts like a trap capturing heat carried in by the Gulf Stream, which brings in ever warmer water. Of all the heat trapped on Earth by greenhouse gases, 90% goes into oceans, while a large part of the remaining 10% goes into melting the snow and ice cover in the Arctic, as described in an earlier post. Such basic conditions make that the Arctic is prone to warming.
Then, there are huge amounts of methane held in sediments under the Arctic Ocean, in the form of hydrates and free gas. Unlike methane releases from biological sources elsewhere on Earth, methane can be released from the seafloor of the Arctic Ocean in large quantities, in sudden eruptions that are concentrated in one area.
Until now, permafrost and the sea ice have acted as a seal, preventing heat from penetrating these methane hydrates and causing further destabilization. As long as there is ice, additional energy will go into melting the ice, and temperatures will not rise. The ice also acts as a glue, keeping the soil together and preventing hydrate destabilization from pressure changes and shockwaves resulting from seismic activity. Once the ice is gone, sediments become prone to destabilization and heat can more easily move down along fractures in the sediment, reaching hydrates that had until then remained stable.
Temperature anomaly March-April-May 2014 (NASA)
When methane escapes from the seafloor of the Arctic Ocean and travels through waters that are only shallow, there is little opportunity for this methane to be broken down in the water, so a lot of it will enter the atmosphere over the Arctic Ocean. The Coriolis effect will spread the methane sideways, but latitudes over the Arctic are relatively short, making the methane return at the same spot relatively quickly, while the polar jet stream acts as a barrier keeping much of the methane within the Arctic atmosphere. In case of large methane eruptions, the atmosphere over the Arctic will quickly become supersaturated with methane that has a huge initial local warming potential.
Hydroxyl levels in the atmosphere over the Arctic are very low, extending the lifetime of methane and other precursors of stratospheric ozone and water vapor, each of which have a strong short-term local warming potential. In June/July, insolation in the Arctic is higher than anywhere else on Earth, with the potential to quickly warm up shallow waters, making that heat can penetrate deep into sediments under the seafloor.
created by Sam Carana, part of AGU 2011 poster
The initial impact of this methane will be felt most severely in the Arctic itself, given the concentrated and abrupt nature of such releases, with the danger that even relatively small releases of methane from the seafloor of the Arctic can trigger further destabilization of hydrates and further methane releases, escalating into runaway warming.
This danger is depicted in the image on the right, showing how albedo changes and methane releases act as feedbacks that further accelerate warming in the Arctic, eventually spiraling into runaway global warming.
The currently very high sea surface temperature anomalies are illustrated by the two images below.
As the image below right shows, sea surface temperatures as high as 18 degrees Celsius (64.4 degrees Fahrenheit) are currently recorded in the Arctic.
Albedo changes and methane releases are only two out of numerous feedbacks that are accelerating warming in the Arctic.
Also included must be the fact that Earth is in a state of energy imbalance. Earth is receiving more heat from sunlight than it is emitting back into space. Over the past 50 years, the oceans have absorbed about 90% of the total heat added to the climate system, while the rest goes to melting sea and land ice, warming the land surface and warming and moistening the atmosphere.
In a 2005 paper, James Hansen et al. estimated that it would take 25 to 50 years for Earth’s surface temperature to reach 60% of its equilibrium response, in case there would be no further change of atmospheric composition. The authors added that the delay could be as short as ten years.
Earth's waters act as a buffer, delaying the rise in land surface temperatures that would otherwise occur, but this delay could be shortened. Much of that extra ocean heat may enter the atmosphere much sooner, e.g. as part of an El Niño event. Another buffer, Arctic sea ice, could collapse within years, as illustrated by the image below.
[ click on image to enlarge ]
The demise of sea ice comes with huge albedo changes, resulting in more heat getting absorbed by the Arctic Ocean, in turn speeding up warming of the often shallow waters of the Arctic Ocean. This threatens to make heat penetrate subsea sediments containing huge amounts of methane. Abrupt release of large amounts of methane would warm up the Arctic even more, triggering even further methane releases in a spiral of runaway warming.
Particularly worrying is the currently very warm water that is penetrating the Arctic Ocean from the Atlantic Ocean and also from the Pacific Ocean, as illustrated by the image further above and the image on the right.
The danger is that the Arctic will warm rapidly with decline of the snow and ice cover that until now has acted as a buffer absorbing heat, with more sunlight gets absorbed due to albedo changes and as with additional emissions, particularly methane, resulting from accelerating warming in the Arctic.
The numerous feedbacks that accelerate warming in the Arctic are pictured in the image below.
Furthermore, the necessary shift to clean energy will also remove the current masking effect of aerosols emitted when burning fuel. One study finds that a 35% – 80% cut in people's emission of aerosols and their precursors will result in about 1°C of additional global warming.
This is further illustrated by the image below, showing how surface temperature rises are accelerating in the Arctic compared to global rises, with trendlines added including one for runaway global warming, from How many deaths could result from failure to act on climate change?
[ click on image to enlarge ]
The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog.
Hat tip to Jim Kirkcaldy for pointing at the wildfire development at an early stage.
