How Much Warming Have Humans Caused?

How much did temperatures rise?

Differences in baseline (reference period) can result in dramatic differences in temperature rise. The U.K. Met Office HadCRUT4 dataset typically presents temperature anomalies relative to a 1961-1990 baseline. NASA typically uses a 1951-1980 baseline, but the NASA website allows for different baselines to be selected. When selecting a 1961-1990 baseline, temperatures over the past half year were 1.05°C (1.89°F) higher than this baseline, as shown by the NASA map in the left panel of the image below. As the map in the right panel of the image below shows, when compared to 1890-1910, temperatures have risen by 1.48°C (or 2.664°F).

A polynomial trend can reduce variability such as caused by volcanoes and El Niño events. The graph below was created with the NASA L-OTI monthly mean global surface temperature anomaly, which has a 1951-1980 baseline, and then with 0.29°C added, which makes the anomaly 0°C in the year 1900 for the added polynomial trend.



This gives an idea of how much temperatures have risen since the year 1900, with a rise for both February and March 2016 showing up that was more than 1.5°C, as also illustrated by the image below. The trend further points at temperature anomalies that will be more than 1.5°C within a decade and more than 2°C soon thereafter.

Historical Temperatures

To calculate by how much warming humans have caused since pre-industrial times, we need to go back further than 1900. The graph below shows that carbon dioxide concentrations have gone up and down between roughly 180 ppm and 280 ppm over the past 800,000 years and did recently reach a peak of 411 ppm (peak hourly average on May 11, 2016).

The graph below, from an earlier post, shows how in the past, over the past 420,000 years, temperatures (and levels of CO2 and CH4) have gone up and down by some 10°C, in line with the Milankovitch cycles.

Historically, carbon dioxide rises of 100 ppm have gone hand in hand with temperature rises of some 10°C. The recent rise in carbon dioxide concentrations is a 131 ppm rise (from some 280 ppm to 411 ppm). The rise in methane concentrations is even steeper. Could we therefore expect a temperature rise of more than 10°C to happen, and if so how soon could this eventuate? As described below, warming caused by humans could result in a temperature rise of more than 10°C (18°F) within a decade.

The graph on the right, created by Jos Hagelaars, shows that, during the most current cycle, temperatures reached a peak some 7000 years ago (in the blue part of the graph).

The graph underneath, based on work by Marcott et al., focuses on this blue part of the graph, while using a 1961-1990 baseline. Temperatures reached a peak some 7000 years ago, and then came down to reach a low a few hundred years ago.

The peak and the bottom temperatures (highlighted in red on image) over the period suggest a fall of more than 0.7°C.

A few hundred years ago, temperatures were falling and they would have kept falling, in line with the Milankovitch cycles, had there been no warming caused by humans.

From that bottom point, temperatures first rose by about 0.4°C, overwhelming the downward trend that would otherwise have taken temperatures down further, and then there was an additional rise of at least 1.05°C, when using a baseline of 1961-1990. That may suggest that humans have caused a total of 1.45°C warming.

Humans have caused even more warming

The situation looks to be even worse than what the above figures may suggest. Indeed, the bottom low point in the Marcott graph would have been even lower had there been no warming by humans. 

Temperatures before 1900 were already higher than what they would have been had humans caused no warming. The fact that humans did cause substantial warming between 1800 and 1900 is illustrated by the graph below, from a recent post by Michael Mann, who adds that some 0.3°C greenhouse warming had already taken place between the year 1800 and the year 1900.

Some 0.3C greenhouse warming had already taken place by 1900, and some 0.2C warming by 1870

Further studies suggest that humans also caused substantial warming well before 1800, as illustrated by the image on the right. While this study focuses on Europe, it does suggest a rise from 1600 to 1800.

Another example of warming caused by humans before 1800 is presented in research by Dull et al., which suggests that burning of Neotropical forests increased steadily in the Americas, peaking at a time when Europeans arrived in the late fifteenth century. By 1650, some 95% of the indigenous population had perished. Regrowth of forests led to carbon sequestration of some 2 to 5 Pg C, thereby contributing to a fall in atmospheric carbon dioxide recorded in Antarctic ice cores from about 1500 through 1750.

Paris Agreement

NASA data suggest that it was 1.48°C (or 2.664°F) warmer than in 1890-1910 for the period from November 2015 to April 2016. Note again that this 1890-1910 baseline is much later than pre-industrial times. The Paris Agreement had pledged to limit the temperature rise to 1.5°C above pre-industrial levels. On land on the Northern Hemisphere, it was 1.99°C (or 3.582°F) warmer (right map of the image below).

[ Temperature anomalies for the period from November 2015 to April 2016, see also comments ]

The above images only account for a half-year period, so they are only indicative for the total rise for the year 2016. Nonetheless, when taking into account warming caused by people before 1900, the year 2016 looks set to exceed the guardrails that the Paris Agreement had pledged would not be crossed. The situation looks even worse when considering that temperatures measured in ice cores already included a substantial amount of warming due to humans even before the start of the Industrial Revolution.

February 2016 was 1.67°C (3°F) warmer than 1890-1910

Again, at the Paris Agreement nations pledged to hold the increase in the global average temperature to well below 2°C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5°C above pre-industrial levels.

When looking at a single month, February 2016 was 1.67°C (3°F) warmer than 1890-1910 (see image right). When adding a mere 0.34°C to account for warming before 1900, total warming in February 2016 did exceed 2°C. Looking at it that way, the guardrails set in Paris in December 2015 were already crossed in February 2016.

Situation

So, what is the situation? On the one hand, there's the current observed temperature rise (∆O). This rise is typically calculated as the difference between the current temperature and the temperature at a given baseline.

However, this ∆O does not reflect the full impact of human emissions. Temperatures would have been lower had there been no emissions by humans. The full warming impact due to people's emissions therefore is ∆E. This ∆E is higher than the often-used observed rise, since the baseline would have been lower without warming caused by humans.

At the same time, part of global warming caused by people is currently masked due the aerosol emissions (∆A). Such aerosol emissions result from mainly burning of fossil fuel and biomass. There's no doubt that such emissions should be reduced, but the fact remains that the current temperature rise may increase substantially, say, by half when the masking effect disappears.

Thus, the full (unmasked) warming caused by humans is the sum of these two, i.e. ∆E + ∆A, and the sum could be as high as 3°C or even more than 5°C.

In addition, there is a future temperature rise that's already baked into the cake (∆F). Some feedbacks are not yet very noticeable, since some changes take time to become more manifest, such as melting of sea ice and non-linear changes due to feedbacks that are only now starting to kick in. Furthermore, the full effect of CO2 emissions reaches its peak only a decade after emission, while even with the best efforts, humans are likely to still be causing additional emissions over the coming decade. All such factors could jointly result in a temperature rise greater than ∆E + ∆A together, i.e. ∆F could alone cause a temperature rise of more than 5°C within a decade.

In summary, total warming caused by humans (∆E + ∆A + ∆F) could be more than 10°C (18°F) within one decade, assuming that no geoengineering will take place within a decade.

The situation is dire and calls for comprehensive and effective action as described in the Climate Plan.


Links

- Methane Erupting From East Siberian Arctic Shelf
http://arctic-news.blogspot.com/2014/11/methane-erupting-from-east-siberian-arctic-shelf.html

- Jos Hagelaars' graph, created with graphs by Shakun et al., Marcott et al. and more, is at:
https://ourchangingclimate.wordpress.com/2013/03/19/the-two-epochs-of-marcott/

- Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation, by Shakun et al. http://www.nature.com/nature/journal/v484/n7392/full/nature10915.html

- A Reconstruction of Regional and Global Temperature for the Past 11,300 Years, by Marcott et al.
http://science.sciencemag.org/content/339/6124/1198

- The Columbian Encounter and the Little Ice Age: Abrupt Land Use Change, Fire, and Greenhouse Forcing, by Dull et al., in:
https://www.sciencenews.org/article/columbus-arrival-linked-carbon-dioxide-drop

- Arctic Climate Records Melting
http://arctic-news.blogspot.com/2016/05/arctic-climate-records-melting.html

- 2500 Years of European Climate Variability and Human Susceptibility, Ulf Büntgen et al. (2011)

http://science.sciencemag.org/content/331/6017/578

- Paris Agreement
http://arctic-news.blogspot.com/2015/12/paris-agreement.html
http://unfccc.int/documentation/documents/advanced_search/items/6911.php?priref=600008831
https://unfccc.int/resource/docs/2015/cop21/eng/l09r01.pdf

- February Temperature
http://arctic-news.blogspot.com/2016/03/february-temperature.html

- Climate Plan
http://arctic-news.blogspot.com/p/climateplan.html

Ten Degrees Warmer In A Decade?

In 2015, mean global carbon dioxide grew by 3.09 parts per million (ppm), more than in any year since the record started in 1959. An added polynomial trendline points at a growth of 5 ppm by 2026 (a decade from now) and of 6 ppm by 2029.

NOAA data, added trend points at 5 ppm growth a decade from now

There are a number of elements that determine how much the total temperature rise will be, say, a decade from now:

Rise 1900-2016: In January 2016, it was 1.92°C (3.46°F) warmer on land than in January 1890-1910, as discussed in an earlier post that also featured the image below.

Rise before 1900: Before 1900, temperature had already risen by ~0.3°C (0.54°F), as Dr. Michael Mann points out.

Rise 2016-2026: The image at the top shows a trend pointing at 5 ppm growth a decade from now. If levels of carbon dioxide and further greenhouse gases keep rising, then that will account for additional warming over the next ten years. Even with dramatic cuts in carbon dioxide emissions, temperatures will keep rising, as maximum warming occurs about one decade after a carbon dioxide emission, so the full wrath of the carbon dioxide emissions over the past ten years is still to come.

Removal of aerosols: With dramatic cuts in emissions, there will also be a dramatic fall in aerosols that currently mask the full warming of greenhouse gases. From 1850 to 2010, anthropogenic aerosols brought about a decrease of ∼2.53 K, says a recent paper. In addition, people will have emitted a lot more aerosols since 2010.

Albedo change: Warming due to Arctic snow and ice loss may well exceed 2 W per square meter, i.e. it could more than double the net warming now caused by all emissions by people of the world, calculated Professor Peter Wadhams in 2012.

Methane eruptions from the seafloor: ". . . we consider release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time," Dr. Natalia Shakhova et al. wrote in a paper presented at EGU General Assembly 2008. Authors found that such a release would cause 1.3°C warming by 2100. Note that such warming from an extra 50 Gt of methane seems conservative when considering that there now is only some 5 Gt of methane in the atmosphere, and over a period of ten years this 5 Gt is already responsible for more warming than all the carbon dioxide emitted by people since the start of the industrial revolution.

Water vapor feedback: Water vapour feedback acting alone approximately doubles the warming from what it would be for fixed water vapour. Furthermore, water vapour feedback acts to amplify other feedbacks in models, such as cloud feedback and ice albedo feedback. If cloud feedback is strongly positive, the water vapour feedback can lead to 3.5 times as much warming as would be the case if water vapour concentration were held fixed, according to the IPCC.

The image below puts these elements together in two scenarios, one with a relatively low temperature rise of 3.5°C (6.3°F) and another one with a relatively high temperature rise of 10°C (18°F).

Temperature rise on land a decade from now (without geoengineering)

Note that the above scenarios assume that no geoengineering will take place within a decade.

[ click on images to enlarge ]

As described above, the January 2016 temperature anomaly on land compared to January 1890-1910 was 1.92°C (3.46°F). Globally, the anomaly was 1.53°C (2.75°F), as shown by the image top right.

Putting the elements together for two global scenarios will result in a total rise of 3.11°C (5.6°F) for a relatively low global temperature rise and 9.61°C (17.3°F) for a relatively high global temperature rise, as shown by the image bottom right.

So, will climate catastrophe occur in a decade or later? There are many indications that the odds are large and growing rapidly. Some say climate catastrophe is inevitable or is already upon us. Others may like to believe the odds were rather small. Even so, the magnitude of the devastation makes it imperative to start taking comprehensive and effective action now.

The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.

In 2015, mean global CO2 grew by 3.09 parts per million, more than in any year since the record started in 1959. An...
Posted by Sam Carana on Wednesday, March 9, 2016

Methane's Role in Arctic Warming

Arctic Ocean hit most strongly by global warming

Over the past 12 months, global warming was felt most strongly over the Arctic Ocean, as above image illustrates. Over most parts of the Arctic Ocean, surface temperatures were above the top end of the scale, i.e. more than 2.5°C higher than in 1981-2010.

In January 2016, air temperatures close to sea level (at 925 hPa) were more than 6°C or 13°F above average across most of the Arctic Ocean, as NSIDC.org announced recenty. Moreover, daily average temperatures over many parts of the Arctic Ocean often exceed the top end of the scale, i.e. 20°C or 36°F higher than in 1979-2000, as illustrated by the Climate Reanalyzer forecast below.

So, how can temperature anomalies over the Arctic Ocean at this time of year be so much higher than elsewhere on Earth?

One factor is feedbacks such as changes to the jet stream and decline of snow and ice cover in the Arctic that makes that ever more sunlight is getting absorbed by the water of the Arctic Ocean, in turn causing further decline, as discussed in many earlier posts.

Right now, however, warming over the Arctic Ocean is very pronounced at a time of year when there is a wider temperature difference between the Arctic and the Equator, while there is little or no sunlight reaching the Arctic. So, albedo changes are less relevant, while changes to the jet stream would be expected to be less prominent now. Nonetheless, a strongly deformed jet stream can push a lot of warm air all the way up to the North Pole, while pushing a lot of cold air out of the Arctic over North America, as illustrated by the forecast on the right.

Let's look at some further factors that are at work.

High levels of greenhouse gases over the Arctic

The question was, why is warming hitting to Arctic Ocean so strongly at this time of year? Greenhouse gas levels are higher over the Arctic than elsewhere on Earth. Greenhouse gases trap heat that would otherwise be radiated out to space, and this greenhouse effect is occurring all year long.

[ click on images to enlarge them ]

Let's look more closely at carbon dioxide (CO2) levels. On February 4, 2016, CO2 level at Mauna Loa, Hawaii, was 405.83 ppm, as illustrated by the image on the right. 

The image below shows that global mean CO2 level on February 6, 2016, was 407 ppm at an altitude close to sea level (972 mb). The image also shows higher CO2 levels at higher latitudes north, with levels over 410 ppm showing up over most of the Northern Hemisphere. 

Carbon dioxide levels on Feb. 8, 2016, were as high as 416 ppm at a location over the Kara Sea (marked by the green circle at the top of the image on the right).

Nonetheless, the levels of carbon dioxide over the Arctic Ocean are not that much higher than elsewhere, i.e. not enough to explain such huge temperature anomalies.

Methane, another greenhouse gas, is also present over the Arctic Ocean at levels that are higher than the rest of the world, as illustrated by the image below, showing methane levels over 1900 ppb over most of the Arctic Ocean on February 4, 2016. 

In the case of methane, the situation is different than for carbon dioxide:

• levels at the North Pole are more than 10% higher than at the South Poles, a much larger difference than for carbon dioxide. 
• methane is reaching its highest levels over the Arctic Ocean from October onward to well into the next year. 
• methane persists longer over the Arctic due to low hydroxyl levels there. 
• methane levels over the Arctic Ocean are high, as increasingly large amounts of methane are rising up from the Arctic Ocean seafloor, making that this methane will inherently be highly concentrated over the Arctic, especially shortly after its release. 

In conclusion, it looks like methane is playing an increasingly large role in warming up the Arctic, especially given its large short-term potency as a greenhouse gas.

from: arctic-news.blogspot.com/p/methane.html

AMOC is carrying ever more heat into the Arctic Ocean

Besides methane, there is another big reason why temperature anomalies are so high over Arctic Ocean at this time of year. Huge amounts of heat are rising up from the water into the atmosphere over the Arctic Ocean, warming up the air over the water. The warmer the sea, the less ice will form. The weaker the ice, the more cracks and spots where heat gets transferred to the atmosphere.

The water of the Arctic Ocean is getting warmer, compared to previous years, as the Gulf Stream heats up. When referring to the full length from the Gulf of Mexico to the Arctic Ocean, this current is often referred to as the North Atlantic Meridional Overturning Circulation (AMOC). The direction of AMOC's flow is determined by two forces, i.e. the flow of warm water from the Equator to the north, and the the flow east due to the Coriolis force. The result is warm, salty water is carried by AMOC in the upper layers of the Atlantic toward the north-east, to Arctic Ocean. Eventually, the water sinks and flows back as colder water through the deep Atlantic. As the NOAA image below shows, the amount of heat that has been carried by AMOC toward the Arctic Ocean has been increasing over the past few years.



Overall ocean temperatures are increasing, as discussed in posts such as Ocean Heat and Temperature Rise. As a result, more heat is getting carried toward the Arctic Ocean now. The Gulf Stream off the coast of North America is warming up strongly and is pushing more heat toward the Arctic ocean, compared to previous years. The result is illustrated by the image below, showing huge sea surface temperature anomalies in the Arctic Ocean near Svalbard, despite the cold lid on the north Atlantic, indicating that the heat is continuing to travel underneath the cold freshwater lid to the Arctic Ocean.

Such high sea surface temperature anomalies are not uncommon in the Arctic Ocean these days. The image below shows that on January 24, 2016, sea surface temperature was 12.3°C or 54.2°F at a location near Svalbard marked by the green circle, a 10.4°C or 18.7°F anomaly.

from: Arctic sea ice area at record low for time of year

Water now much warmer off the North American coast

The water off the east coast of North America is much warmer than it used to be due to emissions that extend from North America over the Atlantic Ocean due to the Coriolis force. The image below, from an earlier post, shows carbon dioxide levels as high as 511 ppm over New York on November 5, 2015, and as high as 500 ppm over the water off the coast of coast of New Jersey on November 2, 2015.

from the post: 2015 warmest year on record

The image below shows carbon monoxide levels. Carbon monoxide depletes hydroxyl, making it harder for methane to be oxidized. So again methane appears to be a major factor.

from: Arctic sea ice area at record low for time of year

Such emissions heat up the Gulf Stream and make that ever warmer water is carried underneath the sea surface all the way into the Arctic Ocean. 

Cold freshwater lid on the North Atlantic

Finally, the cold freshwater lid on the North Atlantic makes that less heat transfer occurs from ocean to atmosphere. This cold freshwater lid makes that more heat is flowing toward the Arctic Ocean just below the sea surface of the North Atlantic. 

sea ice speed and drift, forecast for February 18, 2016

This cold freshwater lid is spreading over the North Atlantic for a number of reasons: 

• more melting of glaciers on Greenland, on Svalbard and in North Canada; 
• more sea ice drifting into the Atlantic Ocean due to stronger winds. Storms move up the Atlantic in a circular way, speeding up sea ice drift along the edges of Greenland, as illustrated by this video and the images on the right;
• stronger evaporation off the east coast of North America, with moisture being carried by stronger winds to the north-east, resulting in more precipitation settling on the water and thus freshwater getting added to the North Atlantic, as illustrated by the image below.

As above image also illustrates, this cold freshwater lid on the North Atlantic could also result in more heat being carried into the Arctic Ocean, due to reduced heat transfer to the atmosphere from water on its way to the Arctic Ocean.

Above image illustrates how higher temperatures over the Arctic (top panel) can go hand in hand with the cold freshwater lid over the North Atlantic (second panel), with high sea surface temperatures off the east coast of North America (third panel) and with higher precipitation over this cold freshwater lid (bottom panel).

The image below indicates that the cold freshwater lid on the North Atlantic also goes hand in hand with falling salinity levels.

Precipitation over the North Atlantic is increasing, due to stronger winds and storms there, as discussed in earlier posts such as this one and as illustrated by the images below. Stronger winds, storms with high levels of precipitation and higher waves can all make the cold freshwater lid spread further across the North Atlantic. 

Above image show that waves as high as 17.81 m or 58.4 ft were forecast for the North Atlantic on February 1, 2016, and as high as 17.31 m or 56.8 ft for February 8, 2016.

Conclusion

In conclusion, the danger is that ever more heat will arrive in the Arctic Ocean. This will result in greater melting of the sea ice, in a self-reinforcing feedback loop that makes that more sunlight gets absorbed by the Arctic Ocean (rather than being reflected back into space, as before).

On February 11, 2016, Arctic sea ice had - for this time of year - the lowest extent since satellite records started in 1979, as illustrated by the image below.

The biggest danger is that, as the Arctic Ocean continues to warm, huge amounts of methane will erupt abruptly from the seafloor of the Arctic Ocean, driving up temperatures over the Arctic dramatically and triggering ever more methane eruptions, resulting in a rapid escalation into runaway warming.

The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.

Over the past 12 months, global warming was felt most strongly over the Arctic Ocean. Over most parts of the Arctic...
Posted by Sam Carana on Thursday, February 11, 2016

September 2015 Sea Surface Warmest On Record

Arctic Sea Ice Extent Growth Seals Off Arctic Ocean

Arctic sea ice increased rapidly in October 2015, after reaching its annual minimum in September. As the image below shows, the growing sea ice extent has effectively sealed off the Arctic Ocean from the atmosphere, resulting in less evaporation and heat transfer from the ocean to the atmosphere.

The Naval Research Laboratory 30-days animation (up to October 22, with forecast added up to October 30) on the right shows that sea ice has grown in extent, adding plenty of very thin sea ice, while the existing ice has hardly increased its thickness.

The Buffer Has Gone

Thick sea ice used to extend meters below the sea surface in the Arctic, where it could consume massive amounts of ocean heat through melting this ice into water. As such, thick sea ice acted as a buffer. Over the years, Arctic sea ice thickness has declined most dramatically. This means that the buffer that used to consume massive amounts of ocean heat carried by sea currents into the Arctic Ocean, has now largely gone.

Latent heat loss, feedback #14 on the Feedbacks page

Cold Freshwater Lid on North Atlantic

Meanwhile, especially from 2012, huge amounts of freshwater have run off Greenland, with the accumulated freshwater now covering a huge part of the North Atlantic, acting as a lid that prevents ocean heat to evaporate from the North Atlantic.

Since it's freshwater that is now covering a large part of the surface of the North Atlantic, it will not easily sink in the very salty water that was already there. The water in the North Atlantic was very salty due to the high evaporation, which was in turn due to high temperatures and strong winds and currents. Freshwater tends to stay on top of more salty water, even though the temperature of the freshwater is low, which makes this water more dense. The result of this stratification is less evaporation in the North Atlantic, and less transfer of ocean heat to the atmosphere, and thus lower air temperatures than would have been the case without this colder surface water.

Cold freshwater lid on North Atlantic, feedback #28 on the Feedbacks page

The cold lid over the North Atlantic has meanwhile expanded. Greenland has been experiencing wild weather swings this month, with temperatures shifting from one extreme end of the scale to the other end. The image below shows temperature anomalies on October 17 (left panel), October 23 (center panel) and a forecast for October 30 (right panel). Temperatures are forecast to swing back to the extreme high end of the scale, pushing up temperature anomalies for the Arctic as a whole to as high as 2.37°C on October 30, 2015.

Wild weather swings causing methane releases, feedback #21 on the Feedbacks page

These wild weather swings over Greenland threaten to cause cracks in the ice, with methane hydrates in the ice becoming destabilized, resulting in releases of huge amounts of methane from hydrates and free gas into the atmosphere, as earlier discussed as feedback #21 on the Feedbacks page.

Strong winds have further contributed to extend the cold lid over the North Atlantic, while also making cold air flow from Greenland over the North Atlantic. This is illustrated by the image below, depicting the situation on October 23, 2015, with the left panel showing surface wind speed, while the right panel shows the resulting sea surface temperature anomalies. 

The video below shows surface wind speed forecasts in the Arctic from October 25 to November 1, 2015.

Ocean Temperature Rise

NOAA analysis shows that the global sea surface in September 2015 was the warmest on record, at 0.81°C (1.46°F) above the 20th century average of 16.2°C (61.1°F). On the Northern Hemisphere, the anomaly was 1.07°C (1.93°F).

[ click on image to enlarge ]

Of all the excess heat resulting from people's emissions, 93.4% goes into oceans. Accordingly, the temperature of oceans has risen substantially over the years and - without action - the situation only looks set to get worse.

The Threat

As ocean temperatures continue to rise, especially in the North Atlantic, the Gulf Stream will keep carrying ever warmer water from the North Atlantic into the Arctic Ocean. Without the buffer of thick sea ice to consume the increasing amount of ocean heat, the threat is that ocean heat will increasingly reach the seafloor and unleash huge methane eruptions from destabilizing clathrates. Such large methane eruptions will then warm the atmosphere at first in hotspots over the Arctic and eventually around the globe, while also causing huge temperature swings and extreme weather events, contributing to increasing depletion of fresh water and food supply, as further illustrated by the image below, from an earlier post.

[ click on image at original post to enlarge ]

October 2015 Sea Surface Temperature Update

The North Atlantic continues to be very warm. Sea surface temperature anomalies were as high as 7.9°C or 14.2°F at a location off the east coast of North America on October 22, 2015. Anomalies were 8.1°C or 14.5°F at that same spot on October 16, 2015.

Sea surface temperature anomalies were as high as 7.5°C or 13.6°F at a location near Svalbard on October 25, 2015. On October 9, 2015, sea surface temperatures were as high as 13.1°C or 55.6°F at that same location near Svalbard (marked by green circle on image below), an anomaly of 9.5°C or 17.2°F. These temperatures indicate that the water can be much warmer below the surface than at the surface, and that this warm water is transported by the Gulf Stream below the surface of the North Atlantic into the Arctic Ocean. The animation below switches between the above two dates and also shows that the cold freshwater lid on the North Atlantic has meanwhile extended further south.

In the Bering Strait, warm water also keeps flowing into the Arctic Ocean. At the location marked by the green circle on the image below, sea surface temperatures were as high as 7.3°C or 45.1°F on October 22, 2015, an anomaly of 5.7°C or 10.2°F.

Methane

The images below show high methane concentrations over the Arctic.

Above image shows methane levels at low altitude on October 22, 2015. Because of its height, there are no data at this altitude for Greenland. The image below shows methane concentrations at a higher altitude, with high methane levels showing up over Greenland on October 16, 2015.

Climate Plan

The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan.

Malcolm Light comments

GLOBAL EXTINCTION IS NOW SIX YEARS CLOSER The following comments refer to Figure 224 below. All historical floating ice appears to have been lost in the Arctic by September 2015 so we can assume that the 5+ year old ice pack has largely gone by this time. The 5+ year old ice pack was only predicted to melt back by 2021.7 consequently this year's volume of ice melting has occurred 6 years earlier than the previous prediction. The previous estimate of the final loss of 1 year Arctic floating ice from polynomial data was 2037.7 which now corrects to 2031.7, 16 years in the future. Previous estimates of when the average atmospheric global temperature anomaly increase would reach 6°C was 2034.7, by which time massive global extinction would be proceeding. The new corrected time for this event is 2034.7 - 6 = 2028.7 which is 13 years in the future. During the major Permian Extinction event, which was caused by a massive methane build-up in the atmosphere, the mean surface atmospheric temperature increased by 5°C over 13 years. As the present mean global surface atmospheric temperature is already greater than 1°C hotter than the mean, we will be looking at at least a 6°C temperature increase by 2028 with its associated global extinction event. This is a frightening correlation between the new predicted 6°C average global surface atmospheric temperature rise and what is known to have occurred during the major Permian extinction event, both of which were caused by a massive buildup of methane in the atmosphere. We are clearly in for a very rough-hot ride in the next decade as the terminal global extinction event approaches. Malcolm P.R. Light (Dr) Earth Scientist Figure 224. Arctic sea ice melt back times estimated from area, volume and thickness anomalies compared to various extinction zones defined by the global atmosphere temperature field. Credit: Malcolm Light. Click on image to enlarge.

Related

- Ocean Temperature Rise
http://arctic-news.blogspot.com/2014/10/ocean-temperature-rise.html

- Ocean Temperature Rise Continues

http://arctic-news.blogspot.com/2014/11/ocean-temperature-rise-continues.html 

- Gulf Stream brings ever warmer water into Arctic Ocean
http://arctic-news.blogspot.com/2015/06/gulf-stream-brings-ever-warmer-water-into-arctic-ocean.html

- The Mechanism leading to Collapse of Civilization and Runaway Global Warming
http://arctic-news.blogspot.com/p/the-mechanism.html

- The Threat of Global Warming causing Near-Term Human Extinction
http://arctic-news.blogspot.com/p/threat.html

- Warming Arctic Ocean Seafloor Threatens To Cause Huge Methane Eruptions
http://arctic-news.blogspot.com/2015/09/warming-arctic-ocean-seafloor-threatens-to-cause-huge-methane-eruptions.html

- Climate Plan
http://arctic-news.blogspot.com/p/plan.html

NOAA analysis shows that the global sea surface in September 2015 was the warmest on record, at 0.81°C (1.46°F) above...
Posted by Sam Carana on Friday, October 23, 2015