Thursday, January 30, 2014

Forecast: America to be hit by temperatures as low as minus 40 degrees

The image on the right shows that large parts of North America, the Arctic Ocean and Siberia are experiencing low temperatures.

What many people may not realize is that temperatures in the Arctic are actually a lot higher than they used to be around this time of year.

Temperatures in the Arctic have risen due to feedbacks as described in the post The Biggest Story of 2013.

As a result, temperature anomalies above 20 degrees Celsius now feature in the Arctic. As the image on the right illustrates, the once-common temperature difference between the Arctic and lower latitudes has been shattered, and this is weakening the Jet Stream and the Polar Vortex, in turn making it easier for cold air to flow down to lower latitudes and for warmer air to enter the Arctic, as described in posts at this blog for years, e.g. this post.

This is illustrated by the image below, showing that the Arctic is hit by an overall temperature anomaly of 6.55 degrees Celsius, while some areas in the Arctic feature anomalies above 20 degrees Celsius.


Forecasts show that on February 2nd, 2014, 1200 UTC, the Arctic will be hit by a temperature anomaly of 7.85 degrees Celsius, while on February 6th, 2014, 1200 UTC, the U.S. will be hit by temperatures as low as -40 degrees, as illustrated by the image below.


The video below shows temperature forecasts from February 1to February 8, 2014.


The video below shows temperatire anomalies from February 2 to February 9, 2014.


Meanwhile, the Gulf Stream keeps pushing warm water into the Arctic Ocean, as illustrated by the image below.

Click on image to enlarge - view updated animation at earth.nullschool.net 
The image below shows how high sea surface temperature anomalies stretch out from the point where the Gulf Stream travels at high speeds, off the coast of North America, all the way into the Arctic Ocean.


This has already resulted in methane eruptions from the seafloor of the Arctic Ocean that started several months ago and are continuing to date - ominous signs of more to come. The image below, which compares peak methane levels at two altitudes between January 2013 and January 2014, suggests that January 2014 peak levels have increased strongly, compared to January 2013 peak levels. Furthermore, that the rise in average peak readings has been most dramatic at the higher altitude.


This suggests that huge quantities of methane have indeed been released from hydrates under the Arctic ocean, and that much of the methane is rising and building up at higher altitudes. The increasing appearance of noctilucent clouds further confirms indications that methane concentrations are rising at higher altitudes.

Of course, the above analysis uses a limited dataset, but if verified by further analysis, it would confirm a dramatic rise in the presence of methane in the atmosphere due to releases from hydrates. Moreover, it would confirm the immensity of threat that releases from the Arctic Ocean will escalate and trigger runaway warming, as high methane concentrations over the Arctic are contributing to the anomalously high temperatures there. The risk that this will eventuate is unacceptable, which calls for comprehensive and effective action such as discussed at the ClimatePlan blog.

Tuesday, January 28, 2014

Methane Man


At the 2014 State of the Union address, President Obama said that the all-of-the-above energy strategy he announced a few years ago is working, describing natural gas as the bridge fuel that can power our economy.

Just do NOT tell them the monster exists
President Obama said: "Businesses plan to invest almost $100 billion in new factories that use natural gas. I’ll cut red tape to help states get those factories built, and this Congress can help by putting people to work building fueling stations that shift more cars and trucks from foreign oil to American natural gas."

President Obama added: "And when our children’s children look us in the eye and ask if we did all we could to leave them a safer, more stable world, with new sources of energy, I want us to be able to say yes, we did."

Methane levels going through the roof
Sadly, President Obama doesn't. President Obama missed yet another opportunity to articulate a plan to shift to genuinely clean energy, and instead chose to persist supporting all types of energy, in particular natural gas.

As the U.S. shifts to natural gas, more methane is entering the atmosphere. At the same time, methane eruptions from the seafloor of the Arctic Ocean continue to contribute to the temperature rises in the Arctic that are making the weather ever more extreme. The image below shows surface temperature anomalies above 20°C in the Arctic, while anomalies below -20°C feature at lower latitudes.



Monday, January 27, 2014

Our New Climate and Weather - part 2



by Paul Beckwith

continued from part 1

In North America we are about to experience a late January, 2014 weather event that will likely go down in the record books, at least for a few weeks until the next event. Such is life on our rapidly changing planet in Climate 2.0, or perhaps this would better be called the great abrupt climate change transition between Climate 1.0 (our old climate) and the new, much warmer Climate 2.0.

In any event, the jet stream is configuring into that two crest/two trough mode that I discussed above. An enormous plug of cold Arctic air is descending southward across North America with temperature anomalies 20 degrees C below normal (36 degrees F below normal). It likely reaches far enough south to enter into northern Mexico and to cover large parts of Florida and extend out into the Gulf of Mexico and the Atlantic, resulting in northern Florida dropping below freezing (see my YouTube video below).

For more commentary on above video, see the post Deep Freeze and Abrupt Climate Change

Meanwhile, in turn, almost the entire Arctic region is seeing huge positive temperature anomalies that are 20 degrees C above normal (36 degrees F above normal). This air is changing the Arctic circulation patterns, and although the Arctic air temperature is still below zero, it is so much warmer than normal that the thickening and area growth of sea ice is being severely curtailed. There is strong ice motion out of the Fram Strait between Greenland and Svalbard which is carrying some of the thickest ridged ice just north of the Canadian archipelago out to warmer water and destruction. In the Bering Strait the ice motion is switching between transport of warm Pacific Ocean water into the Arctic Ocean and export of cold Arctic Ocean water out into the Pacific, leading to less ice formation outside the strait.


The easternmost and westernmost edges of North America are outside the jet stream trough, and being in the ridge on either side of the trough are experiencing record warm temperatures. Snow is minimal there, and lakes that would normally have frozen long ago are open water. Further south on the west coast, California is undergoing a record drought and the Sierra Nevada snow pack which feeds the rivers and reservoirs in the state is only at 15 to 20% of normal levels. And this is the normal rainy season for California, which is the breadbasket of the nation. If this drought continues, as it has for almost 3 years, it is very likely that food prices will increase substantially across North America.

Putting on my Engineering hat, it is very clear to me that the large temperature swings over short periods of time that occur as the jet stream troughs and ridges sweep past a fixed region such as a city are wreaking havoc on infrastructure. We have commonly been getting temperature swings of 40 degrees Celsius (72 degrees F) within a day or two. These swings usually cross zero, and result in torrential rain events followed by flash freezing and then large amounts of snow, or the inverse process occurs, often in a cycle over a week. Clearly buildings, roads, railroad tracks, and pipelines are under siege from these temperature swings, precipitation changes and repeated freeze/thaw cycles.

Consider a railroad track. The rails are basically two ribbons of steel of length L separated by width w that are held in place by spikes onto wooden railroad ties. Each section L is joined to adjacent sections with spacers. The tracks are designed for a nominal temperature range. At the high end temperature, the steel expands to its maximum length, and adjacent sections butt together at the join. At the low end temperature, the steel contracts and the gap between adjacent rails is at a maximum. As the daily temperature varies between the lows and highs, the rail expands and contracts. Similarly, for seasonal changes. All within design tolerances. What we are seeing now is a higher frequency of extreme temperature swings of 40 degrees C or larger (72 degrees F), which is greatly stressing the rail infrastructure. These large swings are stretching the limits of the design tolerances since they exceed the usual daily temperature ranges, and occur way faster than any seasonal change. In combination with the explosion of rail traffic from oil trains, the risk of derailment accidents has greatly increased, and we are seeing an enormous increase in derailments. We have also seen a large increase in the frequency, amplitude, duration, and spatial area of torrential rainfall events which have led to floods and extreme river flow rates which undercuts bridges and also leads to more rail derailments. Especially when the rail is submerged for extended periods of time, as occurred, for example in Colorado in late summer 2013.

Ditto with pipelines. Pipeline sections are attached to each other via welds or sleeves and during extreme temperature swings the expansion and contraction of concern is in the longitudinal direction of the pipe. The pipelines are usually buried a few meters under the ground, which can reduce the temperature variation during the atmospheric temperature swings, however where they cross rivers and streams they are exposed to the changing elements and river flows. They are also susceptible to flash freeze events in which large sections of the ground contract and lead to cracking and soil displacement. Water saturation levels in the soils has a large effect on pipeline stresses, and can undergo rapid changes from rapidly changing precipitation cycles.

We are all familiar with how roads fare under extensive freeze/thaw cycles. Even worse, the ice melting salt corrodes guardrails, signs, and posts and as cracks open up in the asphalt salty water percolates in and the freeze thaw cycles widen the cracks leading to potholes and road breakup. And that is in northern latitude regions that have a regular snow in winter climate. In more southern regions that are unaccustomed to snow, there is widespread use of concrete for road surfaces. When there are large temperature swings the concrete is more prone to cracking and it is more difficult to remove snow and ice from these roads, since there is a lack of snow removal equipment and salt in these regions, and the concrete is lighter in color and thus absorbs less solar energy than asphalt and thus stays colder.

The biggest problem that homeowners face in more southern latitudes from these deep freeze situations, apart from personal discomfort in poorly insulated homes, is water pipe freezing and rupturing. Leaving the water taps all partially open to ensure a trickle of water flow through the pipes alleviates a lot of this problem.

In summary, climate change caused extreme weather events are severely stressing infrastructure like roads, bridges, rail, pipelines, and buildings. Much of this infrastructure was built many years ago and upgrading and maintenance has been neglected due to postponed and reduced budgets; while traffic on rail, for example has exploded in volume and weight. We are now facing the consequences of accelerated climate change and the years of neglect of our aging infrastructure.

In the video below, Paul says more about the damage to railway tracks and pipelines.



Southern Hemisphere Climate Changes

In the video below, Paul Beckwith explains how declining Arctic sea ice is causing Australia to bake and Antarctic sea ice to grow.


to be continued

Saturday, January 25, 2014

Higher Altitude Methane Rise

Dramatic methane releases from the Arctic Ocean seafloor have been documented at this blog over the past few months. While the most recent IPCC figures for emissions from hydrates and permafrost are only 7 Tg per year, a recent post estimates current emissions from hydrates at 99 Tg per year, a figure that is growing rapidly. Furthermore, as discussed in an earlier post, the IPCC's estimated annual increase in global methane levels may seem small, but this figure appears to be based on low-altitude data collected over the past few decades.

These high methane releases undoubtedly contribute to higher global levels, but they may not (as yet) translate into higher global averages due to the way data are collected and figures are averaged and calculated. 

Global levels can be calculated by adding up and averaging readings from all measuring stations around the world. This works well for conventional emissions such as from wetlands, from agriculture or from burning fuel. Such emissions originate from numerous land-based sources that are spread out over large areas, while each emitting relatively small quantities of methane periodically or continuously, which makes it easy for hydroxyl to brake down this type of methane before it rises up into the air. Thus, such emissions can be relatively easily measured from land-based measuring stations. 

By contrast, the Arctic Ocean covers only 2.8% of the Earth's surface and releases from hydrates originate in only parts of the Arctic Ocean. Thus, the methane that enters the atmosphere over the Arctic Ocean is very concentrated to start with. Furthermore, hydroxyl levels in the Arctic atmosphere are low, especially at this time of year. As a result, much of the methane that enters the atmosphere over the Arctic Ocean will rise higher up into the atmosphere without being broken down, and much of the methane will continue to be present over the Arctic for years, exercizing methane's very high initial warming potential. 

There are only a few measuring stations in the Arctic and they are all land-based, making that measurements can be taken at altitudes that are too low to capture the full scale of the methane concentrations that have formed as a result of methane releases from the Arctic Ocean seafloor over the past few months. The local nature and further characteristics of releases from the Arctic Ocean can make that they are underestimated or even ignored in measurements taken at land-based stations and in global levels that are calculated from such data. 

The situation can be tested by looking at peak levels of methane showing up at specific altitudes, as measured by satellite sensors, specifically at two altitudes, i.e. at 14,385 Ft (or 4,385 m) and at 19,820 Ft (or 6,041 m), since methane as measured by the IASI MetOp polar-orbiting satellite shows up most prominently at these altitudes over the Arctic. Thus, to detect methane originating from hydrates under the Arctic Ocean, it's best to look at peak levels at these altitudes. The image below shows IASI data available in January 2013 and in January 2014, for these two altitudes.  





The results of this analysis are quite disturbing, for two reasons. Firstly, January 2014 peak levels have increased strongly, compared to January 2013 peak levels. Secondly, the rise in average peak readings has been most dramatic at the higher altitude (from 2066 ppb in 2013 to 2240 ppb in 2014). 

This suggests that huge quantities of methane have indeed been released from hydrates under the Arctic ocean, and that much of the methane is rising and building up at higher altitudes. The increasing appearance of noctilucent clouds further confirms indications that methane concentrations are rising at higher altitudes. 

Of course, the above analysis uses a limited dataset, but if verified by further analysis, it would confirm a dramatic rise in the presence of methane in the atmosphere due to releases from hydrates. Moreover, it would confirm the immensity of threat that releases from the Arctic Ocean will escalate and trigger runaway warming. The risk that this will eventuate is unacceptable, which calls for comprehensive and effective action such as discussed at the ClimatePlan blog

Saturday, January 18, 2014

Our New Climate and Weather


by Paul Beckwith

The familiar global weather patterns that we, our parents, and our grandparents (and most of our distant ancestors, at least as far back as the last ice age remnants) have always experienced are no more. We have entered an abrupt climate change phase in which an energized water primed atmosphere and disrupted circulation patterns give rise to unfamiliar, massive and powerfully destructive storms, torrential rains, widespread heat waves and droughts, and less commonly but occasionally widespread cold spells.

Why is this happening now? Sophisticated Earth System computer Models (ESMs), summaries of state-of-the-art peer reviewed climate science (Intergovernmental Panel on Climate Change IPCC), and mainstream science have generally put the climate change threat out to the latter part of the century. Global data from all parts of the world, but most noticeably the Arctic shows that reality is quite different from these models and mainstream thinking.

Just by looking out the window much of humanity now senses that something is very different, and uncomfortably wrong in their particular region.

Depending on location, vegetation is drying out and burning, or being toppled by very high wind events, or oceans are invading upon coastlines, or rivers are overrunning banks or drying up or both, while rainfall deluges are inundating other regions. In fact some regions are vacillating between massive floods and massive droughts, or record high temperatures and record low temperatures, even on a weekly basis.

As crazy as things are now, clearly they are not bad enough to wake up the general population enough to vote down denier politicians and demand extensive governmental action on the problem. Not to worry, that action is a sure bet in the near future, the only question is will it happen next year, or in 3 years?

In the meantime, many of us are doing as much as we can to educate people on the dangers we face and speed up the understanding of climate reality process. As much as we do, ultimately it is the hammer of extreme weather, causing, for example global crop failures or taking out a few more cities in rich countries that will take the final credit for an abrupt tipping point in human behavior.

The key to the disruption in the climate system is the Arctic.

Human emissions have inexorably increased levels of carbon dioxide and methane (Greenhouse gases GHGs) in the atmosphere sufficiently to cause an incremental overall increase of global mean surface temperature by 0.8 degrees C over the last century. Over the last 3 decades, the GHGs have caused sufficient warming in the Arctic to melt enough land-covered snow and ocean covered ice such that the highly reflective surfaces have been replaced by dark underlying land and ocean greatly increasing sunlight absorption causing Arctic temperature amplification of 3x to 5x and higher.

This has melted permafrost on the land and on the shallow continental shelves and has increased Arctic methane emissions, which on a molecule-to-molecule basis cause warming >150x compared to carbon dioxide on a short timescale. Arctic temperature amplification has reduced the equator-to-Arctic temperature difference, which is responsible for setting up global circulation patterns on the rotating Earth. Thus, the high speed jet stream winds which circumvent the globe become slower, and wavier, and weather patterns change.

Extreme weather events become stronger, more frequent, of longer duration, and act on new regions. In effect, the climate background has changed, so the statistics of all weather events changes. When the ocean tide comes in all boats rise, when the climate system changes all weather events change.

So how does the North American freeze of early January, 2014 and the upcoming late January, 2014 freeze fit into this picture? In our familiar climate, the polar jet stream flowed mostly west to east (with small north-south deviations or waves, with typically 4 to 7 crests and troughs around the globe) separating cold dry Arctic air from lower latitude warmer moist air. The latitude of the jet moves southward in our winter and northward in our summer.

In our present climate the jet stream waviness has greatly increased and eastward average speed has decreased. Not only that, but in early January there were only two troughs (over North America and central Asia) and two crests (over Europe and the Pacific up through Alaska and the Bering Strait).

The troughs had temperatures 20 degrees C cooler than normal, while the crests had temperatures 20 degrees C warmer than normal. These large waves and slowing of the jet stream is directly responsible for the changes we have been experiencing in weather extremes. Cold or warm, depending on your location.

continued at part 2

Thursday, January 16, 2014

High methane levels over the Arctic Ocean on January 14, 2014

[ click on image to enlarge - note that 'level' is the peak reading for the respective altitude ]
Above image shows IASI methane levels on January 14, 2014, when levels as high as 2329 ppb were recorded. This raises a number of questions. Did these high methane levels originate from releases from the Arctic Ocean, and if so, how could such high methane releases occur from the seafloor of the Arctic Ocean at this time of year, when temperatures in the northern hemisphere are falling?

Location

Let's first establish where the methane releases occurred that caused these high levels. After all, high methane concentrations are visible at a number of areas, most prominently at three areas, i.e. at the center of the Arctic Ocean, in Baffin Bay and over an area in Asia stretching out from the Taklamakan Desert to the Gobi Desert.

Closer examination, illustrated by the inset, shows that the highest methane levels were recorded in the afternoon, and at altitudes where methane concentrations over these Asian deserts and over Baffin Bay were less prominent, leading to the conclusion that these high methane levels did indeed originate from the seafloor of the Arctic Ocean.

The image below, showing 1950+ ppb readings over the past few days, illustrates the magnitude of the methane concentrations over the Arctic Ocean.


High concentrations persist over the Arctic Ocean

High methane concentrations have persistently shown up over the Arctic Ocean from October 1, 2013, through to January 2014. On January 19, 2014, levels as high as 2363 ppb were recorded over the Arctic Ocean, as illustrated by the image below.

[ click on image to enlarge ]
Causes

What caused these high releases from the seafloor of the Arctic Ocean to persist for so long? At this time of year, one may have thought that the water in the Arctic Ocean would be much colder than it was, say, on October 1, 2013.

Actually, as the combination image below shows, sea surface temperatures have not decreased much at the center of the Arctic Ocean between early October, 2013 (left) and January 14, 2014 (right). In the area where these high methane concentrations occured, sea surface temperatures have remained the same, at about zero degrees Celsius.

[ click on image to enlarge ]
Furthermore, as the above image shows, surface temperatures in the Atlantic Ocean may have fallen dramatically with the change of season, but temperatures in the Arctic Ocean have changed only little.

In this case of course, what matters more than surface temperatures are water temperatures at greater depth. Yet, even here temperatures in the Arctic Ocean will have decreased only slightly since early October 2013, as the Gulf Stream has continued to push warmer water into the Arctic, i.e. water warmer than the water in the Arctic Ocean. In other words, the heating impact of the Gulf Stream has continued.

Furthermore, as the sea ice extent increased, there have been less opportunities for the heat to evaporate on the surface and for heat to be transferred from the Arctic Ocean to the air.

Finally, what matters a lot is salinity. The combination image below compares salinity levels between October 1, 2013 (left), and January 14, 2014 (right).

[ click on image to enlarge ]
Salinity levels were low on October 1, 2013, as a lot of ice and snow had melted in the northern summer and rivers had carried a lot of fresh water into the Arctic Ocean. After October 1, 2013, little or no melting took place, yet the Gulf Stream continued to carry waters with higher salt levels from the Atlantic Ocean into the Arctic Ocean.

Annual mean sea surface salinity
Seawater typically has a salinity level of over 3%; it freezes and melts at about −2°C (28°F). Where more saline water from the Atlantic Ocean flows into the Arctic Ocean, the water in the Arctic Ocean becomes more saline. The freezing and melting point of fresh water (i.e. zero salinity) is 0°C (or 32°F). More salinity makes frozen water more prone to melting, i.e. at temperatures lower than 0°C, or as low as −2°C.

As the salinity levels of the water on the seafloor of the Arctic Ocean increased, the ice that had until then held the methane captive in hydrates on the seafloor of the Arctic Ocean started to melt. Indeed, the areas in the Arctic Ocean where the high methane releases occurred on January 14, 2014 (top image) show several practical salinity units (psu) increase since October 1, 2013.

Higher salinity levels are now reaching the faultline that runs through the Arctic Ocean from the top of Greenland to the Laptev Sea, where major releases are taking place now, as illustrated by the image below, with faultlines added on the insets.

[ click on image to enlarge ]
Above image shows methane levels recorded on the evening of January 16, 2014 (main image). The top left inset shows all methane readings of 1950 ppb and higher on January 15 and 16, 2014, while the bottom left inset shows methane readings of 1950 ppb and higher on January 16, 2014, p.m. only and for seven layers only (from 469 to 586 mb), when levels as high as 2353 ppb were reached (at 469 mb).

Quantities

These high levels of methane showing up over the Arctic Ocean constitute only part of the methane that did escape from the seafloor of the Arctic Ocean. Where these high concentrations did show up, the ocean can be thousands of meters deep, giving microbes plenty of opportunity to decompose methane rising through the water first. Furthermore, the methane has to pass through sea ice that is now getting more than one meter thick in the area where these high levels of methane showed up on satellite records. In conclusion, the quantities of methane that were actually released from the seafloor must have been huge.

Importantly, these are not one-off releases, such as could be the case when hydrates get destabilized by an earthquake. As the Arctic-news blog has documented, high releases from the seafloor of the Arctic Ocean have been showing up persistently since early October 2013, i.e. three months ago. This blog has warned about the threat for years. This blog has also described in detail the mechanisms that are causing these releases and the unfolding climate catastrophe that looks set to become more devastating every year.

Given that a study submitted in April 2013 concluded that 17 Tg annually was escaping from the East Siberian Arctic Shelf alone, given the vast quantity of the releases from hydrates that show up on IASI readings and given the prolonged periods over which releases from hydrates can persist, I put the methane being released from hydrates under the seafloor of the Arctic Ocean in the highest category, rivaling global emissions from fossil fuel, from agriculture and from wetlands. As said, the amounts of methane being released from hydrates will be greater than the methane that actually reaches the atmosphere. To put a figure on the latter, my estimate is that emissions from hydrates and permafrost currently amount to 100 Tg annually, a figure that is growing rapidly. This 100 Tg includes 1 Tg for permafrost, similar to IPCC estimates.



This is vastly more than the IPCC's most recent estimates, which put emissions from hydrates and permafrost at 7 Tg annually, a mere 1% of the total annual methane emissions globally, as illustrated by the image below.


Impacts and Response

Huge releases from the seafloor of the Arctic Ocean have occurred persistently since early October 2013, even when releases like this may show up for one day in one area without showing up in that same area the next day on satellite images.

This apparent 'disappearance' can be due to the Coriolis effect that appears to move the methane, whereas it is in fact the Earth that is spinning underneath the methane. This doesn't mean that the methane had disappeared. Actually, much of this methane will persist over the Arctic for many years to come and will continue to exercize its very high initial warming potential over the Arctic for years.

Furthermore, even if less methane may show up on satellite images the next day, that doesn't necessarily mean that releases from the seafloor has stopped. Instead, it looks like methane is being released continuously from destabilizing hydrates. The methane may accumulate underneath the sea ice for some time, to burst through at a moment when fractures or ruptures occur in the sea ice, due to changes in wind and wave height.


The threat here is that methane will further warm up the air over the Arctic, causing further weakening of the Jet Stream and further extreme weather events, particularly extreme warming of water all the way along the path of the Gulf Stream from the Atlantic Ocean into the Arctic Ocean, in turn triggering further releases from hydrates at the seafloor of the Arctic Ocean and escalating into runaway global warming. This threat calls for comprehensive and effective action, such as described at the ClimatePlan blog.





Saturday, January 11, 2014

Arctic in early January 2014

In early January 2014, Arctic sea ice extent reached levels as low as they were in early January 2013, as illustrated by the image below.


Methane levels over the Arctic remain extremely high. The image below shows methane readings for the period January 1 - 11, 2014, with the inset showing the situation in 2013 for the same period.


Similarly, the image below makes a comparison between methane recorded in 2013 and in 2014 for this period (January 1-11), this time focusing on the Arctic and only showing methane readings of 1950 ppb and higher in yellow.


Below a combination of images by Dr. Leonid Yurganov, also comparing methane levels between early 2013 and 2014. The difference isn't as marked in the image below as in the above image, as the highest value in the image below is 1920+ ppb, whereas the above image highlights levels of 1950+ ppb.


These high methane releases from the seafloor of the Arctic Ocean are contributing to the over 20°C temperature anomalies that have hit parts of the Arctic Ocean recently, as illustrated by the image below.

In conclusion, the Arctic is hit by three kinds of warming, while there are at least 13 feedbacks that further accelerate warming in the Arctic, as described in the post The Biggest Story of 2013.