Showing posts with label Greenland. Show all posts
Showing posts with label Greenland. Show all posts

Monday, April 8, 2019

Blue Ocean Event Consequences

A Blue Ocean Event looks set to occur in the Arctic when there will be virtually no sea ice left. At first, the duration of this event will be a few weeks in September, but as more heat accumulates in the Arctic, the event will last longer each year thereafter.

Indeed, a Blue Ocean Event will come with accumulation of more heat, due to loss of latent heat, as a dark (blue) ocean absorbs more sunlight than the reflective ice, etc. Consequences will extend far beyond the Arctic, as shown on the image below that features Dave Borlace's Blue Ocean Top Ten Consequences.


Dave Borlace goes into more detail regarding these consequences in the video Blue Ocean Event : Game Over?


A Blue Ocean Event could happen as early as September 2019. The image below shows that Arctic sea ice extent on April 7, 2019, was 12.97 million km², a record low for measurements at ads.nipr.ac.jp for the time of year. By comparison, on May 28, 1985, extent was larger (13.05 million km²) while it was 51 days later in the year.


In the video below, Paul Beckwith also discusses the rapid decline of the sea ice and the consequences.


Clearly, the rapid decline of the sea ice has grave consequences. When also looking beyond what's happening in the Arctic, there are further events, tipping points and feedbacks that make things worse. An earlier post contains the following rapid warming scenario:
  1. a stronger-than-expected El Niño would contribute to
  2. early demise of the Arctic sea ice, i.e. latent heat tipping point +
  3. associated loss of sea ice albedo, 
  4. destabilization of seafloor methane hydrates, causing eruption of vast amounts of methane that further speed up Arctic warming and cause
  5. terrestrial permafrost to melt as well, resulting in even more emissions,
  6. while the Jet Stream gets even more deformed, resulting in more extreme weather events
  7. causing forest fires, at first in Siberia and Canada and
  8. eventually also in the peat fields and tropical rain forests of the Amazon, in Africa and South-east Asia, resulting in
  9. rapid melting on the Himalayas, temporarily causing huge flooding,
  10. followed by drought, famine, heat waves and mass starvation, and
  11. collapse of the Greenland Ice Sheet.


Importantly, depicted above is only one scenario out of many. Things may eventuate in different order and occur simultaneously, i.e. instead of one domino tipping over the next one sequentially, many events reinforcing each other. Further points should be added to the list, such as falling away of sulfate cooling due to economic changes, ocean stratification and stronger storms that can push large amounts of warm salty water into the Arctic Ocean.

Global sea ice extent is also at a record low for the time of year. Global sea ice extent on April 8, 2019, was 17.9 million km². On April 8, 1982, global sea ice extent was 22.32 million km², i.e. a difference of 4.42 million km². That constitutes a huge albedo loss.


As discussed in an earlier post, this all adds up to further global warming that may eventuate very rapidly. The image below shows how a total rise of 18°C or 32.4°F from preindustrial could eventuate by 2026.



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


Links

• Blue Ocean Event : Game Over? - by Dave Borlace
https://www.youtube.com/watch?v=qo3cznpfIpA

• Climate System Upheaval: Arctic Sea-Ice, Snow Cover, Jet-Stream, Monsoonal Consequences - by Paul Beckwith
https://www.youtube.com/watch?v=ZtpF--rqZZ8

• Jet Stream Center-of-Rotation to Shift 17 degrees Southward from North Pole to Greenland with Arctic Blue Ocean Event - by Paul Beckwith
https://www.youtube.com/watch?v=bFme3C9e-cs

• Blue Ocean Event
https://arctic-news.blogspot.com/2018/09/blue-ocean-event.html

• Stronger Extinction Alert
https://arctic-news.blogspot.com/2019/03/stronger-extinction-alert.html

• It could be unbearably hot in many places within a few years time
https://arctic-news.blogspot.com/2016/07/it-could-be-unbearably-hot-in-many-places-within-a-few-years-time.html

• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html

• Latent Heat
https://arctic-news.blogspot.com/p/latent-heat.html

• Albedo and more
https://arctic-news.blogspot.com/p/albedo.html

• Warning of mass extinction of species, including humans, within one decade
https://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html

• How much warming have humans caused?
https://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html

• The Threat
https://arctic-news.blogspot.com/p/threat.html

• A rise of 18°C or 32.4°F by 2026?
https://arctic-news.blogspot.com/2019/02/a-rise-of-18c-or-324f-by-2026.html

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

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


Saturday, March 23, 2019

Climate Tipping Points

Paleoclimate perspectives of 21st-23rd centuries, IPCC projections and tipping points

by Andrew Glikson
Earth and paleo-climate scientist
Australian National University

Abstract

IPCC models of future climate trends contain a number of departures from patterns deduced from the paleoclimate evidence. With CO₂ levels reaching 411.8 ppm in January 2019 and CH₄ levels reaching 1.867 ppm in October 2018, for a greenhouse radiative forcing factor of CH₄=25 CO₂ equivalents, the total CO₂-equivalent of 457.5 ppm¹ approaches the stability limit of the Greenland ice sheet, estimated at a greenhouse gas forcing of approximately 500 ppm CO₂ although ephemeral ice may have existed as far back as the middle Eocene. As the concentration of greenhouse gases is rising and amplifying feedbacks from land, oceans and ice sheet melting increase, transient temperature reversals (stadials) accentuate temperature polarities between warming land masses and oceanic regions cooled by the flow of cold ice melt water from the ice sheets, leading to extreme weather events. The rise in Arctic temperatures, at a rate twice as fast as that of lower latitudes, weakens the polar boundary and results in undulation of the jet stream, allowing warm air masses to shift north across the boundary, further heating the polar region. The weakened boundary further allows cold air masses to breach the boundary shifting away from the Arctic. Combined with the flow of ice melt water from Greenland, these developments are leading to a cooling of sub-polar oceans and adjacent land. Similar growth of cold water pools occur along the fringes of Western Antarctica. The cold water pools cover deeper warmer salt water layers which melt the frontal glaciers. The slow-down of the AMOC is analogous to Pleistocene (2.6-0.01 Ma) and early Holocene stadial freeze events such as the Younger Dryas (12.9 – 11.7 kyr) and the 8.5 kyr Laurentide ice melt, where peak temperatures were followed closely by sharp cooling. Climate projections by Hansen et al. (2016) suggest a stadial event associated with significant sea level rise and involving sharp cooling of approximately -2°C, lasting several decades between the mid-21 st century and the mid-22nd century, a time dependent on the rate of Greenland and Antarctic ice melt. Accelerating ice melt and nonlinear sea level rise would reach multi-meters levels over a timescale of 50–150 years.

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¹ January 2019: CO₂ = 410.8 ppm https://www.esrl.noaa.gov/gmd/ccgg/trends/ ; October 2018: CH₄ 1.8676 ppm (CO₂ equivalent x25 = 46.7 CO₂e) https://www.esrl.noaa.gov/gmd/ccgg/trends_ch4/

Paleoclimate records

Pleistocene paleo-climate records are marked by abrupt warming and cooling events during both glacial periods (Dansgaard-Oeschger (D-O) cycles; Ganopolski and Rahmstorf 2001; Camille and Born, 2019) and stadial interglacial periods, the latter defined as stadial freeze events (Figure 1). The paleo-climate record indicates that during the last ~450,000 years peak interglacial temperatures were repeatedly succeeded by temporary freeze events, attributed to the flow of cold ice melt water flow into the North Atlantic Ocean (Cortese et al. 2007) (Figure 1), associated with rapid rises in sea level, as during the last glacial termination (Figure 2). The rise in extreme weather events associated with current global warming to ~0.9°C above 1884 level (NASA, 2018) compares with temperatures and extreme weather events associated with the early Holocene Period (~11.6 –7.0 kyr), a period of major sea level rise of ~60 meters (Smith et al. 2011) and with the Eemian interglacial (128-116 kyr). During the Eemian tropical and extratropical North Atlantic cyclones may have been more intense than at present, and may have produced waves larger than those observed historically, as evidenced by large boulders transported by waves generated by intense storms and cliff erosion (Roverea et al. 2017). Sea levels during the Eemian, when temperatures were about +1°C or and sea levels were +6 to +9 m higher than during the late Holocene, offer analogies with current developments (Roverea A et al. 2017; Kaspar et al. 2007).

Figure 1. (A) Evolution of sea surface temperatures in 5 glacial-interglacial transitions recorded in ODP
1089 at the sub-Antarctic Atlantic Ocean. Lower grey lines – δ¹⁸O measured on Cibicidoides plankton;
Black lines – sea surface temperature. Marine isotope stage numbers are indicated on top of diagrams.
Note the stadial temperature drop events following interglacial peak temperatures, analogous
to the Younger Dryas preceding the onset of the Holocene (Cortese et al. 2007⁽²⁵⁾).
(B) Mean temperatures for the late Pleistocene and early Holocene.

With CO₂ levels reaching 411.8 ppm in January 2019 and CH₄ reaching 1.867 ppm in October 2018, for a greenhouse radiative forcing factor of CH₄=25 CO₂e, the total CO₂-equivalent of 457.5 ppm¹ approaches Miocene levels (Gasson et al. 2016). Levy et al. (2016), Tripati and Darby (2018) and other considered the implications of the rise of greenhouse levels above about 500 ppm CO₂ for the future of the Greenland ice sheet. Whereas due to hysteresis² of the ice sheets may delay complete melting, the extreme rate of warming (Figure 3) may in part override this effect.

Anthropocene tipping points

During the late Anthropocene³, accelerating since about 1960, the rise of radiative forcing due mainly to increasing greenhouse gas concentration above >457 ppm CO₂-equivalent, accounts for a rise of mean global temperatures by 0.98°C since 1880 (NASA (2018) A further rise by more than >0.5°C is masked by aerosols, mainly sulphur dioxide and sulfuric acid (Hansen et al., 2011).

The temperature rise is potentially further enhanced by amplifying feedbacks from land and oceans, including infrared absorption by water surfaces following sea ice melting, reduction of CO₂ concentration in warming water, release of methane and fires. However, climate change trajectories are likely to be highly irregular as a result of stadial ocean cooling events affected by flow of ice melt. Whereas similar temperature fluctuations including stadial events have occurred during past interglacial periods (Cortese et al. 2007; figure 1), with a further rise in atmospheric greenhouse gases the intensity and frequency of extreme weather events would enter uncharted territory unlike any recorded during the Pleistocene, potentially rendering large parts of the continents uninhabitable (Wallace-Wells, 2019).

Figure 2. Tipping points in the Earth system (Lenton et al., 2008)
https://www.pik-potsdam.de/services/infodesk/tipping-elements/kippelemente
Creative Commons BY-ND 3.0 DE license.

Expressions of climate tipping points include intensifying climate feedbacks such ice sheet and sea ice melting, declining Atlantic circulation, intensifying monsoons, increasing El-Nino events, heatwaves and fires, rainforest dieback, melting permafrost and breakdown of methane clathrates (Figure 2) (Lenton et al., 2008). According to the Potsdam Climate Impacts Institute (PIK), tipping points include transformation of the Amazon Rainforest, retreat of the Northern Boreal Forests, destruction of Coral Reefs and weakening of the Marine Carbon Pump, melting of the Arctic Sea Ice, loss of the Greenland Ice Sheet, collapse of the West Antarctic Ice Sheet, partial Collapse in East Antarctica, melting of the Yedoma Permafrost and methane Emissions from the Ocean (Schellnhuber, 2009).

Figure 3. Atmospheric carbon dioxide rise rates and global warming events: a comparison between current
global warming, the Paleocene-Eocene Thermal Event (PETM) and the last Glacial Termination. 

The rate at which atmospheric greenhouse gases and temperatures are rising exceeds global warming rates of the PETM and of last glacial termination and is the fastest recorded in Cenozoic record, excepting that associated with asteroid impacts (Figure 3). Ice mass loss would raise sea level by several meters in an exponential rather than linear response, with doubling time of ice loss yielding multi-meter sea level rise. Modelled 2055-2100 AIB model forcing of +1.19°C above 1880-1920 leads to a projected global warming trend which includes a transient drop in temperature, reflecting stadial freezing events in the Atlantic Ocean and the sub-Antarctic Ocean, reaching -2°C over several decades (Figure 7) (Hansen et al., 2016). These authors used paleoclimate data and modern observations to estimate the effects of ice melt water from Greenland and Antarctica, showing cold low-density meltwater tends to cap increasingly warm subsurface ocean water, affecting an increase ice shelf melting. This affects acceleration of ice sheet mass loss (Figure 4) and slowing of deep water formation (Figure 5).

Figure 4. Greenland and Antarctic ice mass change. GRACE data are extension of Velicogna et al. (2014)
gravity data. MBM (mass budget method) data are from Rignot et al. (2011). Red curves are gravity data for
Greenland and Antarctica only; small Arctic ice caps and ice shelf melt add to freshwater input. (Hansen et al. 2016)
Figure 5. (a) AMOC (in Sverdrup) at 28°N in simulations (i.e., including freshwater injection of 720 Gt year⁻¹ in 2011
                around Antarctica, increasing with a 10-year doubling time, and half that amount around Greenland).
(b) SST (°C) in the North Atlantic region (44–60°N, 10–50°W).

Future trends and Tipping points

Whereas the precise nature tipping point/s ensuing from the confluence of numerous processes (Figure 2) remains little defined, the weakened boundaries between the Arctic and sub-Arctic zones (Figure 7) and the build-up of cold ice melt pools in the oceans fringing Greenland and Antarctica represent an initial stage in the development of a stadial freeze. The warming of the Arctic, formed approximately 3.6-2.2 million years ago when CO₂ levels were about 400 ppm and polar temperatures near 2°C higher than in the late Holocene, heralds conditions somewhat similar to those of the Pliocene. Whereas reports of the International Panel of Climate Change (IPCC, 2018) (Figure 9), based on thousands of peer reviewed science papers and reports, offer a confident documentation of past and present processes in the atmosphere (Climate Council 2018), the portrayal of mostly linear temperature rise trends need to be questioned. Already early stages of a stadial event are manifest by the build-up of a large pools of cold water in the North Atlantic Ocean south of Greenland (Figure 6A) (Rahmstorf et al., 2015) and at the fringe of West Antarctica (Figure 6A) signify early stages in the development of a stadial freeze in large parts of the oceans, consistent with the decline in the Atlantic Meridional Ocean Circulation (AMOC) (Figure 6A).

Figure 6. (A) 2018 global temperature (NASA);
(B) projected 2055-2100 surface-air temperature to +1.19°C above 1880-1920
(AIB model modified forcing, ice melt to 1 meter) (Hansen et al., 2016).
These projections differ markedly from linear model trends (Figure 9) of IPCC models, which mainly assume long term ice melt (Ahmed, 2018). Rignot et al. (2011) report that in 2006 the Greenland and Antarctic ice sheets experienced a combined mass loss of 475 ± 158 Gt/yr, equivalent to 1.3 ± 0.4 mm/yr sea level rise”. For the Antarctic ice sheet the IEMB team (2017) states the sheet lost 2,720 ± 1,390 billion tonnes of ice between 1992 and 2017, which corresponds to an increase in mean sea level of 7.6 ± 3.9 millimeter (IMBIE team 2017). Hansen et al. (2008) consider global temperature higher than 1.0°Celsius due to CO₂ level of ~450 ppm would lead to irreversible ice sheet loss, given most climate models did not include amplifying feedbacks effects such as ice sheet disintegration, vegetation migration, and greenhouse gas release from soils, tundra, or ocean sediments. Such feedbacks can lead to climate tipping points leading to irreversible runaway climate change (Ahmed, 2018).

Figure 7. Global surface-air temperature to the year 2300 in the North Atlantic and Southern Oceans,
including stadial freeze events as a function of Greenland and Antarctic ice melt doubling time (Hansen et al., 2018)

According to NOAA (2018) Arctic surface air temperatures continue to warm at twice the rate relative to the rest of the globe (Figure 8B), leading to a loss of 95 percent of its oldest ice over the past three decades. Arctic air temperatures for 2014-18 have exceeded all previous records since 1900 and are driving broad changes within the Arctic as well he sub-Arctic through weakening of the jet stream which separates the Arctic from warmer climate zones. The recent freezing storms in North America represent penetration of cold air masses through a weakening and increasingly undulating jet stream barrier (Figure 8A). This weakening also allows warm air masses to move northward, further warming the Arctic and driving further ice melting. The freezing storms in North America (Figure 8C) are cheering those who refuse to discriminate between the climate and the weather.

Figure 8. – A. The weakened undulating Jet stream bounding the polar vortex.
Red represents the fastest air flow (Berwyn 2016). The "big freeze" in North America
results from a slow-moving depression of a Rossby wave⁵. The troughs and ridges of
these waves carry wind around the world and generally have a speed rating
of six or seven, with higher numbers representing faster moving winds;
B. The North American and Siberian freeze event 30 January 2019 (NOAA Global
Forecast system model) (Francis 2019). Predicted near-surface air temperature
differences from normal, relative to 1981-2010. Pivotal Weather, CC BY-ND (Francis 2019);
C. North America is experiencing the weather pattern on the left, while Europe enjoys the other one.

IPCC models of future climate change (Figure 9) contain a number of departures from patterns deduced from the paleoclimate evidence. The role of feedbacks from land and water, estimates of future ice melt rates, sea level rise rates, rates of methane release from permafrost and the extent of fires in enhancing atmospheric CO₂, and the already observed onset of ocean cooling south of Greenland and fringes of Antarctica freeze events need to be quantified. According to Hansen et al. (2016) ice mass loss would raise sea level by several meters in an exponential rather than linear response even within the 21st century. According to Rignot et al. (2011) the Greenland and Antarctic ice sheets experienced in 2006 a combined mass loss of 475 ± 158 billion tons per year.

According to a Met Office briefing evaluating the implications of the UN report, once we go past 1.5°C, we dramatically increase the risks of floods, droughts, and extreme weather that would impact hundreds of millions of people. According to the IPCC this would just be the beginning: as we are currently on track to hit 3-4°C by end of century (Figure 9), which would lead to a largely unlivable planet (Ahmed, 2018). The progressive melting of Greenland and the Arctic Sea ice, formed in the Pliocene approximately 3.6-2.2 million years ago when CO₂ levels were about 560-400 ppm (Stone et al. 2010). Future climate model projections by the IPCC (Figure 9) contain a number of significant departures from observations based on the paleoclimate evidence. This includes factors related to amplifying feedbacks from land and water, ice melt rates, temperature trajectories, sea level rise rates, methane release rates, the role of fires, and observed onset of transient stadial (freeze) events. As the Earth continues to heat, cold air masses breach the Arctic boundary and move southward and warm air penetrates into the Arctic, temperature contrasts between polar and subpolar climate zones decrease, further weakening the polar divide. Temperature contrasts between Arctic-derived cold air masses and subtropical air masses result in an increase in the intensity and frequency of extreme weather events.

Figure 9. IPCC AR5: Time series of global annual mean surface air temperature anomalies relative to 1986–2005
from CMIP5 (Coupled Model Inter-comparison Project) concentration-driven experiments.
Projections are shown for each RCP for the multi model mean (solid lines) and the 5–95% range
(±1.64 standard deviation) across the distribution of individual models (shading) (Easterbrook 2014).⁽⁴⁾

As the Earth warms, the increase in temperature contrasts across the globe, and thereby an increase in storminess and extreme weather events, occurring at present, need to be taken into account when planning adaptation measures, including preparation of coastal defenses, construction of channel and pipelines from heavy precipitation zones to draught zones. A non-linear climate warming trend, including stadial freeze events, bears significant implications for planning future adaptation efforts, including preparations for transient deep freeze events in parts of Western Europe and eastern North America for periods lasting several decades (Figure 7) and coastal defenses against enhanced sea levels and storms. In Australia this should include construction of water pipelines and channels from the flooded north to parched regions such as the Murray-Darling basin.

_________________________
² Hysteresis: The phenomenon in which the value of a physical property lags behind changes in the effect causing it, as for instance when magnetic induction lags behind the magnetizing force.
³ The Anthropocene is a proposed epoch dating from the commencement of significant human impact on the Earth's 
geology and ecosystems. https://en.wikipedia.org/wiki/Anthropocene
⁴ Steve Easterbrook, New IPCC Report (Part 6). Azimuth. https://johncarlosbaez.wordpress.com/2014/04/16/what-does-the-new-ipcc-report-say-about-climate-change-part-6/
https://oceanservice.noaa.gov/facts/rossby-wave.html
https://www.dw.com/en/understanding-the-polar-vortex/a-17347788


Andrew Glikson
Dr Andrew Glikson
Earth and Paleo-climate science, Australia National University (ANU) School of Anthropology and Archaeology,
ANU Planetary Science Institute,
ANU Climate Change Institute,
Honorary Associate Professor, Geothermal Energy Centre of Excellence, University of Queensland.

Books:
The Archaean: Geological and Geochemical Windows into the Early Earth
The Asteroid Impact Connection of Planetary Evolution
Asteroids Impacts, Crustal Evolution and Related Mineral Systems with Special Reference to Australia
Climate, Fire and Human Evolution: The Deep Time Dimensions of the Anthropocene
The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth
Evolution of the Atmosphere, Fire and the Anthropocene Climate Event Horizon
From Stars to Brains: Milestones in the Planetary Evolution of Life and Intelligence


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https://www.penguin.com.au/books/the-uninhabitable-earth-9780241400517

Sunday, July 17, 2016

High Methane Levels Follow Earthquake in Arctic Ocean

In the 12 months up to July 14, 2016, 48 earthquakes with a magnitude of 4 or higher on the Richter scale hit the map area of the image below, mostly at a depth of 10 km (6.214 miles).


As temperatures keep rising and as melting of glaciers keeps taking away weight from the surface of Greenland, isostatic rebound can increasingly trigger earthquakes around Greenland, and in particular on the faultline that crosses the Arctic Ocean.

Two earthquakes recently hit the Arctic Ocean. One earthquake hit with a magnitude of 4.5 on the Richter scale on July 9, 2016. The other earthquake hit with a magnitude of 4.7 on the Richter scale on July 12, 2016, at 00:15:24 UTC, with the epicenter at 81.626°N 2.315°W and at a depth of 10.0 km (6.214 miles), as illustrated by the image below.


Following that most recent earthquake, high levels of methane showed up in the atmosphere on July 15, 2016, over that very area where the earthquake hit, as illustrated by the image below.


Above image shows that methane levels were as high as 2505 ppb at an altitude of 4,116 m or 13,504 ft on the morning of July 15, 2016. At a higher altitude (of 6,041 m or 19,820 ft), methane levels as high as 2598 ppb were recorded that morning and the magenta-colored area east of the north-east point of Greenland (inset) looks much the same on the images in between those altitudes. All this indicates that the earthquake did cause destabilization of methane hydrates contained in sediments in that area.

Above image, from another satellite, confirms strong methane releases east of Greenland on the afternoon of July 14, 2016, while the image below shows high methane levels on July 16, 2016, along the faultline that crosses the Arctic Ocean.


The image on the right shows glaciers on Greenland and sea ice near Greenland and Svalbard on July 15, 2016. Note that clouds partly obscure the extent of the sea ice decline.


Above image shows the sea ice on July 12, 2016. There is a large area with very little sea ice close to the North Pole (left) and there is little or no sea ice around Franz Josef Land (right). Overall, sea ice looks slushy and fractured into tiny thin pieces. All this is an indication how warm the water is underneath the sea ice.

[ click on image to enlarge ]
In addition to the shocks and pressure changes caused by earthquakes, methane hydrate destabilization can be triggered by ocean heat reaching the seafloor of the Arctic Ocean. Once methane reaches the atmosphere, it can very rapidly raise local temperatures, further aggravating the situation.

Temperatures are already very high across the Arctic, as illustrated by the image below, showing that on July 16, 2016, it was 1.6°C or 34.8°F over the North Pole (top green circle), while it was 32.7°C or 90.8°F at a location close to where the Mackenzie River flows into the Arctic Ocean (bottom green circle).

Arctic sea ice is in a very bad shape, as also illustrated by the Naval Research Laboratory nowcast below.


Sea ice thickness has fallen dramatically over the years, especially the ice that was more than 2.5 m thick. The image below compares the Arctic sea ice thickness (in m) on July 15, for the years from 2012 (left panel) to 2015 (right panel), using Naval Research Laboratory images.

[ Click on image to enlarge ]
The image below shows sea surface temperature anomalies from 1961-1990 on July 24, 2016.


Sea surface temperatures off the coast of America are high and much of this ocean heat will be carried by the Gulf Stream toward the Arctic Ocean over the next few months.


On July 24, 2016, sea surface temperature near Florida was as high as 33.2°C or 91.7°F, an anomaly of 3.7°C or 6.6°F from 1981-2011 (bottom green circle), while sea surface temperature near Svalbard was as high as 17.3°C or 63.2°F, an anomaly of 12.6°C or 22.8°F from 1981-2011 (top green circle).

A cold freshwater (i.e. low salinity) lid sits on top of the ocean and this lid is fed by precipitation (rain, hail, snow, etc.), melting sea ice (and icebergs) and water running off the land (from rivers and melting glaciers on land). This lid reduces heat transfer from ocean to atmosphere, and thus contributes to a warmer North Atlantic where huge amounts of heat are now carried underneath this lid toward the Arctic Ocean. The danger is that more ocean heat arriving in the Arctic Ocean will destabilize clathrates at the seafloor and result in huge methane eruptions, as discussed in earlier posts such as this one.

As temperatures keep rising, snow and ice in the Arctic will decline. This could result in some 1.6°C or 2.88°F of warming due to albedo changes (i.e. due to decline both of Arctic sea ice and of snow and ice cover on land). Additionally, some 1.1°C or 2°F of warming could result from methane releases from clathrates at the seafloor of the world's oceans. As discussed in an earlier post, this could eventuate as part of a rise from pre-industrial levels of as much as 10°C or 18°F, by the year 2026.

[ click on image to enlarge ]



The impact of rising temperatures will be felt firstly and most strongly in the Arctic, where global warming is accelerating due to numerous feedbacks that can act as self-reinforcing cycles.

Already now, this is sparking wildfires across the Arctic.

Above image shows wildfires (indicated by the red dots) in Alaska and north Canada, on July 15, 2016.

The image on the right shows smoke arising from wildfires on Siberia. The image below shows that, on July 18, 2016, levels of carbon monoxide (CO) over Siberia were as high as 32318 ppb, and in an area with carbon dioxide (CO2) levels as low as 345 ppm, CO2 reached levels as high as 650 ppm on that day.

[ click on images to enlarge them ]
The image below shows the extent of smoke from wildfires in Siberia on July 23, 2016.


The image below shows high methane levels over Siberia on July 19, 2016.


The image below, from the MetOp satellite, shows high methane levels over Siberia on July 21, 2016.

Below are further images depicting mean global methane levels, from 1980-2016 (left) and 2012-2016 (right).

The image below shows methane levels at Barrow, Alaska.


The image below shows that, while methane levels may appear to have remained stable over the past year when taking measurements at ground level, at higher altitudes they have risen strongly.


The conversion table below shows the altitude equivalents in feet, m and mb.
57016 feet44690 feet36850 feet30570 feet25544 feet19820 feet14385 feet 8368 feet1916 feet
17378 m13621 m11232 m 9318 m 7786 m 6041 m 4384 m 2551 m 584 m
 74 mb 147 mb 218 mb 293 mb 367 mb 469 mb 586 mb 742 mb 945 mb

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




Sunday, July 19, 2015

Arctic Sea Ice Collapse Threatens - Update 1

The image below compares the Arctic sea ice thickness (in m) on July 15, for the years from 2012 (left panel) to 2015 (right panel), using Naval Research Laboratory images.

Click on image to enlarge
The image below compares the Arctic sea ice concentration (in %) on July 18, for the years from 2012 (left panel) to 2015 (right panel), using Naval Research Laboratory images.


Above images show the dramatic decline of the sea ice in 2015, both in thickness and in concentration.

In terms of thickness, sea ice has been reduced by more than one meter in many places, such as north of Greenland and the Canadian Archipelago, all in the time span of just one month.

The dramatic fall in sea ice concentration also becomes apparent when comparing recent sea ice concentration (July 18, 2015, above right) with sea ice concentration back in May 2015 (image right, May 1, 2015).

This dramatic decline of the sea ice in 2015 is the result of a combination of factors, including:

  1. High levels of greenhouse gases over the Arctic Ocean, as illustrated by the image below, showing that on July 17, 2015 (pm), levels as high as 2512 parts per billion were recorded at 6,041 m (19,820 ft) altitude, while mean methane levels were 1830 parts per billion at this altitude.
  2. High levels of ocean heat, as illustrated by the image below showing high sea surface temperatures off the east coast of North America; much of this ocean heat will be carried by the Gulf Stream into the Arctic Ocean over the next few months.
  3. High air temperatures over North America and Siberia extending over the Arctic Ocean, as illustrated by the image below showing a temperature of 23.1°C (73.7°F), recorded on July 19, 2015, at Banks Island, in the Canadian Archipelago (green circle).
  4. Wildfires triggered by these heatwaves resulting in darkening compounds settling on snow and ice, as illustrated by the image below showing smoke covering a wide area on July 19, 2015, from the east Siberia over North America to the southern tip of Greenland.
  5. Very warm river water running into the Arctic Ocean, as illustrated by the image below, showing sea surface temperatures as high as 19°C (66.2°F) off the coast of Alaska on July 12-15, 2015.
The image below shows the already very high sea surface temperature anomalies as at July 18, 2015.

The Climate Reanalyzer image below shows the high sea surface temperature anomalies in the Pacific Ocean, and where water enter the Arctic Ocean through the Bering Strait, on July 19, 2015.



With still two months of melting to go before the sea ice can be expected to reach its minimum for 2015, the threat of sea ice collapse is ominous. The Arctic-News Blog has been warning for years about the growing chance of a collapse of the sea ice, in which case huge amounts of sunlight that previously were reflected back into space, as well as heat that previously went into melting the ice, will then instead have to be absorbed by the water, resulting in a dramatic rise of sea surface temperatures.

More open water will then come with an increased chance of storms that can cause high sea surface temperatures to be mixed down all the way to seafloor of the Arctic Ocean, which in many cases is less than 50 m (164 ft) deep. This is the case for the East Siberian Arctic Shelf, where experts estimate that huge amounts of methane are contained in subsea sediments. Already now, sea surface temperatures as high as 10°C (~50°F) are recorded there, as illustrated by the image below.


Massive amounts of ocean heat will be carried by the Gulf Stream into the Arctic Ocean over the next few months. The combined result of high sea surface temperatures being mixed down to the seafloor and the ocean heat entering the Arctic Ocean from the Atlantic and Pacific Oceans can be expected to result in dramatic methane eruptions from the Arctic Ocean seafloor by October 2015.

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



Arctic sea ice thickness on July 15, compared over the years 2012 through to 2015. Already virtually all the thick sea...

Posted by Sam Carana on Thursday, July 16, 2015