Showing posts with label climate. Show all posts
Showing posts with label climate. Show all posts

Wednesday, September 16, 2020

Temperatures threaten to become unbearable

Many people could face unbearable temperatures soon. 

Temperature anomalies on land in the Northern Hemisphere (red) are spread out much wider and they are more than 0.5°C higher than global land+ocean anomalies (blue).


The pale green and grey trends are both long-term trends based on January 1880-August 2020 NOAA data. The short-term red and blue trends, based on January 2013-August 2020 NOAA data, are added to show the potential for a rapid rise. How could temperatures possibly rise this fast? 

A rapid temperature rise could eventuate by 2026 due to a number of contributing factors:
• crossing of the latent heat and methane tipping points
• moving toward an El Niño 
• entering solar cycle 25
• changes in aerosols
• feedbacks kicking in more strongly as further tipping points get crossed.

Crossing the Latent Heat and Methane Hydrate Tipping Points

The image below, updated from an earlier post, shows two such tipping points.


The August 2020 ocean temperature anomaly on the Northern Hemisphere was 1.13°C above the 20th century average. The image shows a trend based on January 1880-August 2020 NOAA data. The latent heat tipping point is estimated to be 1°C above the 20th century average. Crossing the latent heat tipping point threatens to cause the methane hydrates tipping point to be crossed, estimated to be 1.35°C above the 20th century average.

Keep in mind that above images show temperature anomalies from the 20th century average, which is NOAA's default baseline. As an earlier analysis points out, when using a 1750 baseline and when using ocean air temperatures and higher Arctic anomalies, we may have already crossed both the 1.5°C and the 2°C thresholds that politicians at the Paris Agreement pledged would not get crossed.

Natural Variability - El Niño and Solar Cycle

Currently, we are currently in a La Niña period, which suppresses air temperatures.

Only a thin layer of sea ice remained left in the Arctic, with extent almost as low as it was in 2012 around this time of year, as discussed in the previous post. As air temperatures dropped in September 2020, Arctic sea ice extent started to increase again about September 15, 2020. This made that a patch of sea ice remained present at the surface of the Arctic Ocean, despite the dramatic thinning of the sea ice. 

When an El Niño event returns, conditions will get worse. 


How long will it take before we'll reach the peak of the upcoming El Niño? NOAA says
El Niño and La Niña episodes typically last nine to 12 months, but some prolonged events may last for years. While their frequency can be quite irregular, El Niño and La Niña events occur on average every two to seven years. Typically, El Niño occurs more frequently than La Niña.
The temperature rise is strongest in the Arctic, as illustrated by the zonal mean temperature anomaly map below. The map has latitude on the vertical axis and shows anomalies as high as 4.83°C or 8.69°F in the Arctic. The North Pole is at the top of the map, at 90° North, the Equator is in the middle, at 0°, and the South Pole is at the bottom, at -90° South. And yes, NASA's default baseline is 1951-1980, so anomalies are even higher when using a 1750 baseline. 


So, what could make the difference next year is an upcoming El Niño. Solar irradiance is also on the rise, in line with the 11-year Solar Cycle.


Above image shows a NOAA graph depicting the current Solar Cycle (24) and the upcoming Solar Cycle (25). 

In 2019, Tiar Dani et al. analyzed a number of studies and forecasts pointing at the maximum in the upcoming Solar Cycle occurring in the year 2023 or 2024.

The analysis found some variation in intensity between forecasts, adding images including the one on the right, which is based on linear regression and suggests that the Solar Cycle 25 may be higher than the previous Solar Cycle 24. 

In 2012, Patrick (Pádraig) Malone analyzed factors critical in forecasting when an ice-free day in the Arctic sea first might occur. 

Patrick concluded that once solar activity moved out of the solar minimum, Arctic sea ice extent would start to crash. Accordingly, a Blue Ocean Event could occur as early as 2021, as illustrated by the image below.  


Further Tipping Points and Feedbacks

Further tipping points and feedbacks can start kicking in more strongly as one tipping point gets crossed. At least ten tipping points apply to the Arctic, as discussed in an earlier post and it looks like the latent heat tipping point has already been crossed. 

Ocean heat is very high in the North Atlantic and the North Pacific, and heat continues to enter the Arctic Ocean. 


Arctic sea surface temperatures and air temperature are now high since ocean heat, previously consumed by sea ice, is now coming to the surface where the sea ice has disappeared.

As above image shows, sea surface temperature anomalies in the Arctic Ocean on September 14, 2020, were as high as 9.3°C or 16.8°F (at the location marked by green circle), compared to the daily average during the years 1981-2011. 

These high sea surface temperature anomalies occur at locations where the daily average during the years 1981-2011 was around freezing point at this time of year.

Part of this ocean heat is rising into the atmosphere over the Arctic Ocean, resulting in high air temperatures that in turn prevent formation of sea ice thick enough to survive until the next melting season. The image on the right shows a forecast of Arctic air temperatures (2 m) that are 5°C higher than 1979-2000 (forecast for October 5, 2020, 18Z run Sep 26, 2020 06Z). 

Methane Danger is High


Ominously, peak methane levels of 2762 parts per billion (ppb) were recorded by the MetOp-1 satellite on the morning of September 20, 2020, at 586 milibar (mb), as above image shows.


Mean methane levels of 1925 ppb were recorded by the MetOp-1 satellite on the morning of September 20, 2020, at 293 mb, as above image shows.


Peak methane levels of 2813 ppb were recorded by the MetOp-1 satellite on the afternoon of September 30, 2020, at 469 mb, as above image shows. 


Methane has been rising most at higher altitudes over the past few years. On September 26, 2020 pm, the MetOp-1 satellite recorded a mean global methane level of 1929 ppb at 293 mb, which is equivalent to a height of 9.32 km or 30,57 ft, i.e. in the lower stratosphere over the North Pole (the top of the troposphere over the Equator is higher, at about 17 km).

Why methane is so important

As illustrated by the image on the right, from an earlier post, high methane levels could be reached within decades, and such a scenario could unfold even without sudden big bursts, but merely due to a continuation of a trend based on data up to 2014. This would obviously result in a huge rise in global temperature. 

A huge rise in global temperature would eventuate even earlier in case of a big burst of methane erupting from the seafloor of the Arctic Ocean. 

Methane's initial global warming potential (GWP) is very high. For the first few years after its release, methane is more than 150 times as strong as a greenhouse gas compared to carbon dioxide, as discussed in an earlier post.

How high are current methane levels? NOAA's May 2020 level for methane was 1874.7 ppb

Using a GWP of 150, this translates into 1.8747 x 150 = 281.205 ppm CO₂e. 

NOAA's figures are conservative, given that NOAA measures methane at marine surface level. 

Anyway, when using this conservative NOAA methane figure of 1874.7 ppb which at a GWP of 150 results in 281.205 ppm CO₂e, and when using an additional 413.6 ppm for recent carbon dioxide levels (NOAA's global May 2020 CO₂ level), these two add up to 694.805 ppm CO₂e, which is 505.195 CO₂e away from the cloud feedback tipping point (1200 CO₂e) that can, on its own, raise global temperatures instantly by 8°C. 

This is illustrated by the image on the right, an update from an earlier post

An additional eruption of methane from the Arctic Ocean into the atmosphere of 505.195 CO₂e translates into 505.195 / 150 = 3.368 ppm or 3368 ppb of methane. 

If the current amount of methane in the atmosphere is about 5 Gt, then 3368 ppb of methane corresponds with an amount of methane just under 9 Gt.

Coincidently, a peak level of 3369 ppb was recorded on August 31, 2018, pm. Granted, there is a large difference between a local peak level and a global mean level, but then again, a much smaller burst of methane can trigger the clouds feedback.

Even a relatively small burst of methane could trigger the clouds feedback, given that it will cause huge heating of the Arctic both directly and indirectly, in turn triggering further eruptions of methane from the seafloor of the Arctic Ocean.

Huge direct heating of the Arctic could occur due to methane's high immediate GWP and its even higher Local Warming Potential (LWP) given that the release takes place in the Arctic, while huge indirect heating of Arctic would occur due to the resulting decline of sea ice and of much of the permafrost on land.

Even a relatively small burst of methane could cause not only albedo losses but also releases of carbon dioxide, methane and nitrous oxide and further fast feedbacks such as a rise in clouds and water vapor, especially over the Arctic Ocean, as illustrated by the image on the right, from the extinction page and an earlier post.

Importantly, the initial trigger to a huge temperature rise by 2026 could be an event that is typically categorized under natural variability, such as an El Niño, increased solar irradiance or a storm causing a sudden large influx of hot, salty water into the Arctic Ocean and causing an eruption of seafloor methane. Indeed, a seemingly small forcing can result in total collapse that takes place so rapidly that any political action will be too little, too late.

The video below illustrates the importance of the Precautionary Principle. The video shows how a seemingly small bump by a forklift causes all shelves in a warehouse to collapse. 


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


Links

• NOAA Global Climate Report - August 2020
https://www.ncdc.noaa.gov/sotc/global/202008

• Multivariate El Niño/Southern Oscillation (ENSO) Index Version 2 (MEI.v2)
https://psl.noaa.gov/enso/mei

• What are El Niño and La Niña?

• NOAA ISIS Solar Cycle Sunspot Number Progression

• Multiple regression analysis predicts Arctic sea ice - by Patrick Malone (Pádraig) Malone 
https://www.facebook.com/Amber.and.Patrick/posts/1140053003062976 

• Prediction of maximum amplitude of solar cycle 25 using machine learning - by Tiar Dani et al. 
https://iopscience.iop.org/article/10.1088/1742-6596/1231/1/012022

• NOAA - Trends in Artmospheric Methane 

• Trends in Atmospheric Carbon Dioxide - global

• When will we die?

• A rise of 18°C or 32.4°F by 2026?

• Most Important Message Ever

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

• Record Arctic Warming
https://arctic-news.blogspot.com/2016/04/record-arctic-warming.html

• Warning of mass extinction of species, including humans, within one decade



Tuesday, May 19, 2020

An uncharted 21-23rd centuries’ climate territory

by Andrew Glikson

Precis

21–23ʳᵈ centuries’ transient ocean cooling events (stadials), triggered by ice melt flow from the Greenland and Antarctic ice sheets into the adjacent oceans, herald conditions analogous in part to those of the Younger Dryas stadial (12.9–11.7 kyr) which succeeded the pre-Holocene Bölling-Allerod thermal maximum. The subsequent Younger Dryas cooling event was associated with penetration of polar air masses and ocean currents, leading to storminess, analogous to recent breaching of the weakened polar jet stream boundary, ensuing in major snow storms in North America and Europe and cooling of parts of the North Atlantic Ocean and parts of the circum-Antarctic ocean triggered by the flow of ice melt water from melting glaciers.

21–23ʳᵈ Centuries’ Stadial freeze events

IPCC climate change projections for 2100-2300 portray linear to curved temperature progressions (SPM-5). By contrast, examination of transient cooling events (stadials) which ensued from the flow of ice melt water into the oceans during peak interglacial warming events portray abrupt temperature variations (Fig. 1). The current flow of ice melt water from Greenland and Antarctica ensuing from Anthropogenic global warming is leading to regional ocean cooling in the North Atlantic near Greenland and around Antarctica (Rahmstorf et al, 2015; Hansen et al. (2016); Bronselaer et al. 2018; Purkey et al. 2018; Vernet et al. 2019) (Fig. 2). The incipient developments of ice melt-derived cold water pools in ocean regions adjacent to the large ice sheets imply portents of future stadial events such as, inexplicably, are not indicated by the predominantly linear IPCC climate projections for the 21–23ʳᵈ centuries (IPCC AR5). By contrast, as modelled by Hansen et al. (2016) and Bronselaer et al. (2018), under high greenhouse gas and temperature rise trajectories (RCP8.5), the ice meltwater flow into the oceans from the Antarctic and Greenland ice sheets would lead to cooling of large regions of the ocean, with major consequences for future climate projections. This would include the build-up of large cool ocean pools in the North Atlantic south of Greenland (Rahmstorf et al, 2015) (Fig. 2A) and around Antarctica (Fig. 2B).

Depending on different greenhouse emission scenarios (IPCC 2019; van Vuren et. al. (2011), including the CO₂ forcing-equivalents of methane (CH4) and nitrous oxide (N2O), the total CO₂–equivalent rise amounts to 496 ppm (NOAA, 2019), close to transcending the melting points of large parts of the Greenland and Antarctica ice sheets. Given the extreme rise in temperature since the mid-20th Century, where the oceans heat contents is rising, an incipient cooling of near-surface sub-Greenland and sub-Antarctic ocean regions raises the question whether incipient stadial events, perhaps analogous to the Younger Dryas stadial (Johnsen et al. 1972; Severinghaus et al. 1998), may be developing?

Interglacials, late Pleistocene and early Holocene stadial events

Stadial effects in the late Pleistocene record follow peak interglacial temperatures (Cortese et al., 2007) (Fig. 1). During the last glacial termination (LGT) stadial effects included the Oldest Dryas at ~16 kyr, the Older Dryas at ~14 kyr and the Younger Dryas at 12.9 - 11.7 kyr (Fig. 3), the latter with sharp transitions as short as 1 to 3 years (Steffensen et al., 2008), signifying a return to glacial conditions. A yet younger stadial event is represented at ~8.4 - 8.2 kyr when large-scale melting of the Laurentian ice sheet ensued in the discharge of cold water via Lake Agasiz (Matero et al. 2017; Lewis et al., 2012) into the North Atlantic Ocean. The Laurentian cooling involved temperature and CO₂ decline of ~25 ppm over ~300 years (Fig. 3B and C) and a decline of the North Atlantic Thermohaline circulation.

Figure 1. (a) Evolution of sea surface temperatures in 5 glacial-interglacial transitions recorded in
ODP 1089 at the sub-Antarctic Atlantic Ocean. 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 following interglacial peak temperatures (Cortese et al. 2007).
 (b) The last glacial maximum and the last glacial termination.
Olds  Oldest Dryas; Old – Older Dryas; Yd – Younger Dryas.

Greenland and Antarctica ice melt events

Oxygen isotopes (¹⁸O/¹⁹O), argon isotopes (⁴⁰Ar/³⁹Ar) and nitrogen isotopes (¹⁵N/¹⁴N) studies of Greenland ice cores (Johnsen et al. 1972; Severinghaus et al. 1998) indicate a rise in temperature to -36°C, followed by a sharp fall to -50°C (Table 1; Fig. 3A). At lower latitudes the mean temperatures drop about -2°C and 6°C (Table 1). In the southern hemisphere temperatures dropped by about -2°C in lower latitudes and about -8°C at high latitudes and (Fig. 4; Table 1) Shakun and Carlson, 2010).

Figure 2. A. The cold ocean region south of Greenland visible on NASA's 2015 global mean temperatures, the warmest year on record since 1880. Colors indicate temperature anomalies (NASA/NOAA; 20 January 2016);
B. Circum-Antarctic summer surface temperatures, showing the large Weddell Sea cold anomaly
and a seasonal warming anomaly in the Ross Sea due to upwelling of warm salty water.


Table 1.

Cooling intervals (stadial events) during late Pleistocene and early Holocene interglacial phases.
Isotopic Stage 
Agemax kyr
Agemin kyr
∆tkyr
TmaxoC SST
TminoC SST
∆ToC 
Stadial MIS 11-12 Ref. A
434 kyr
424 kyr
10 kyr
19.3oC SST
13.4oC SST
-5.9oC
Stadial MIS 9-10  Ref. B
346 kyr
331 kyr
5 kyr
19oC SST
13oC SST
-6oC
Stadial MIS 7-8   Ref. C
243.5 kyr
241.5 kyr
2.0 kyr
18oC SST
15.5oC SST 
-2.5oC
Stadial MIS 5-6 Ref. D
136 kyr
130 kyr
6.0 kyr
19oC SST
15.2oC SST
-3.8oC
Younger Dryas stadial ice core In Greenland
MIS 1-2-3  Ref. E
12.86 kyr
11.64 kyr
1.22 kyr
Greenland ice core
-50oC Greenland ice core
-14±3oC
Greenland ice core
Younger Dryas at lower and mid-latitudes of the NH (Fig. 4) Ref. F
12.86 kyr
11.64 kyr
1.22 kyr


-2 to -6oC
8.3 kyr Stadial  Ref. G
8.45 kyr
8.1 kyr
0.35 kyr
-28oC
CO₂=310 ppm
-30oC
CO₂=275 ppm
-2.0oC
Figure 3. A. Temperature variations during the late Pleistocene to the beginning of the Younger Dryas stadial
and the onset of the Holocene, determined as proxy temperatures from ice cores of the central Greenland ice sheet;
B. The ~8.2 kyr stadial event in a coupled climate model (Wiersma et al. 2011);
C. Reconstructed CO₂ concentrations for the interval between ~8,700 and ~6,800 B.P. 

based on CO₂ extracted from air in Antarctic ice of Taylor Dome (Wagner et al. 2002).
Figure 4. Magnitude of late Holocene glacial-interglacial temperature changes in relation to latitude.
Black squares are the Northern Hemisphere (NH), gray circles the
Southern Hemisphere (SH) (Shakun and Carlson, 2010)

Antarctic ice melt dynamics


Circum-Antarctic surface air temperatures, precipitation and sea-ice cover (Bronselaer et al. (2018), including testing the effects of ice-shelf melting, identifies penetration of relatively warm circumpolar deep water below 400 m into the grounding line underlying the ice shelf (Figs 5, 6A). The flow of ice melt water into the adjacent ocean forms an upper cold water layer away from ice shelf areas (Figure 6B). These authors indicate the flow of ice-sheet meltwater results in a decrease of global atmospheric warming, shifts rainfall northwards, and increases sea-ice area and offshore subsurface Antarctic Ocean temperatures.

Figure 5. Schematic circulation and water masses in the Antarctic continental shelf (Purkey et al., 2018) displaying layering of the sub-Antarctic into a cold ice melt-derived upper layer (-2.1°C) overlying a warmer water zone (-1.0°C) which acts as a source of modified warm water penetrating the grounding zone of the glacial ice shelf.

Figure 6. A. The grounding zone where the bedrock-grounded ice sheet transits to a freely floating ice shelf over several km. The floating ice shelf changes in elevation in response to tides, atmospheric air pressure and oceanic processes. B. The Helium (∆He% - Temperature proxy) profile in the Amundsen Sea. The black dots indicate the sampling depth, and the grey dotted lines indicate the isopycnal (density) lines. The shelf break is located at about ∼280 km).

In turn warmer salty water from the circum-polar deep water (CDW) from the circum-Antarctic current can penetrate below the cold off-shelf layer, as is the case in the Weddell Sea Gyre (Figures 5, 6 and 7).

Figure 7. Penetration of relatively warm and salty water from the circum-Antarctic current below the cold off-shelf surface layer of the Weddell Sea Gyre.

Global stadial cooling events


Hansen et al. (2016) suggest that, depending on ice melt rates of the polar ice sheets, transient cooling events (stadials) can be expected to develop at times dependent on the rates of ice melt (Fig. 8). The model is consistent with a slowdown of the Atlantic Meridional Ocean Circulation (AMOC) (Weaver et al. 2012) and the exceptional growth of a cold water region southeast of Greenland, (Rahmstorf et al, 2015). These authors suggest stadial cooling of about -2°C lasting for several decades (Fig. 8B), depending on ice melt rates, can affect temperatures in Europe and North America.

Figure 8. A. Model surface air temperature (°C) change in 2055–2060 relative to 1880–1920 for modified forcings.
B. Surface air temperature (°C) relative to 1880–1920 for several ice melt scenarios.

According to Bronselaer et al. (2018) temporal evolution of the global-mean surface-air temperature (SAT) shows meltwater-induced cooling translates to a reduced rate of global warming (Fig. 9), with a maximum divergence between standard models and models which include the effects of meltwater induced cooling of 0.38 ± 0.02°C in 2055. The SAT response shows the effect of ice meltwater becomes weaker as the ocean becomes more stratified as a result of both moderate to deep level warming and cooling/freshening at the surface (Fig. 6B). As stated by the authors “We demonstrate that the inclusion in the model of ice-sheet meltwater reduces global atmospheric warming, shifts rainfall northwards, and increases sea-ice area”, and “Antarctic meltwater is therefore an important agent of climate change with global impact, and should be taken into account in future climate simulations and climate policy.”
Figure 9. A. 2080–2100 meltwater-induced sea-air temperature anomaly relative to the standard RCP8.5 ensemble. Hatching indicates where the anomalies are not significant at the 95% level.
B. Time series of the global-mean sea-air temperature (SAT) anomaly relative to the 1950–1970 mean.
Orange shows the standard ensemble and blue shows the meltwater-included ensemble. Solid lines show ensemble means, the dark shading shows the 95% uncertainty in the mean and the light shading shows the full ensemble spread of 20-year means. The green bar indicates the period when the standard and meltwater ensembles diverge.

Based on the paleoclimate record, global warming and rates of melting and surface cooling around parts of Antarctica and the North Atlantic (Fig. 2) would determine the future climate of large parts of Earth. Transient stadial cooling events, inherently associated with meters-scale sea level rise, would result in increased temperature polarities between subpolar and tropical latitudes, leading to storminess where polar-derived and tropical-derived air masses and ocean currents collide. Regional to global stadial cooing would, in principle, last as long as ice sheets remain. Once the large ice sheets are exhausted a transition takes place toward tropical Miocene-like and even Eocene-like conditions about 4 to 5 degrees Celsius warmer than Holocene climate conditions, which allowed agriculture and thereby civilization to emerge.


Andrew Glikson
Dr Andrew Glikson
Earth and Paleo-climate scientist
ANU Climate Science Institute
ANU Planetary Science Institute
Canberra, Australia

Books:
The Asteroid Impact Connection of Planetary Evolution
http://www.springer.com/gp/book/9789400763272
The Archaean: Geological and Geochemical Windows into the Early Earth
http://www.springer.com/gp/book/9783319079073
Climate, Fire and Human Evolution: The Deep Time Dimensions of the Anthropocene
http://www.springer.com/gp/book/9783319225111
The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth
http://www.springer.com/gp/book/9783319572369
Evolution of the Atmosphere, Fire and the Anthropocene Climate Event Horizon
http://www.springer.com/gp/book/9789400773318
From Stars to Brains: Milestones in the Planetary Evolution of Life and Intelligence
https://www.springer.com/us/book/9783030106027
Asteroids Impacts, Crustal Evolution and Related Mineral Systems with Special Reference to Australia
http://www.springer.com/us/book/9783319745442


Tuesday, December 17, 2019

Extinction in 2020?


Above image depicts how humans could go extinct as early as 2020. The image was created with NASA LOTI 1880-Nov.2019 data, 0.78°C adjusted to reflect ocean air temperatures (as opposed to sea surface temperatures), to reflect higher polar temperature anomalies (as opposed to leaving out 'missing' data) and to reflect a 1750 baseline (as opposed to a 1951-1980 baseline), with two trends added. Blue: a long-term trend based on Jan.1880-Nov.2019 data. Red: a short-term trend, based on Jan.2009-Nov.2019 data, to illustrate El Niño/La Niña variability and how El Niño could be the catalyst to trigger huge methane releases from the Arctic Ocean.

How was above image created? Let's first look at the baseline. The NASA default baseline is 1951-1980. The added trend in the image below shows early 1900s data to be well below this 1951-1980 baseline. In this analysis, a 0.28°C adjustment was therefore used to reflect this, and to reflect a 1750 baseline, a further 0.3°C was used, adding up to a 0.58°C baseline adjustment.


Furthermore, the NASA Land+Ocean temperature index (LOTI) uses sea surface temperatures, but ocean air temperatures seem more appropriate, which adds a further 0.1°C adjustment. Also, when comparing current temperatures with preindustrial ones, it's hard to find data for the polar areas. Treating these data as 'missing' would leave important heating out of the picture. After all, the polar areas are heating up much faster than the rest of the world, and especially so in the Arctic region. Therefore, a further 0.1°C adjustment was used to reflect higher polar temperature anomalies, resulting in the above-mentioned 0.78°C adjustment.

Finally, the red trend illustrates El Niño/La Niña variability. As discussed in a recent post, an El Niño is forecast for 2020 and this could be the catalyst to trigger huge methane releases from the Arctic Ocean.

The image below shows El Niño/La Niña variability going back to 1950, added to the NOAA monthly temperature anomaly.



As said, the Arctic region is heating up much faster than the rest of the world. There are several reasons why this is the case. Decline of the sea ice makes that less sunlight gets reflected back into space and that more sunlight is reaching the Arctic Ocean. This also causes more water vapor and clouds to appear over the Arctic Ocean. Furthermore, Arctic sea ice has lost most of the thicker multi-year ice that used to extend meters below the surface, consuming huge amounts of ocean heat entering the Arctic Ocean along ocean currents from the North Atlantic and the North Pacific oceans.

[ created with NOAA Arctic Report Card 2019 image ]
Above-mentioned feedbacks (albedo changes and more water vapor and clouds) contribute to higher temperatures in the Arctic. Furthermore, as the temperature difference between the North Pole and the Equator narrows, the jet stream changes, which can lead to further Arctic heating, i.e. higher temperatures of the atmosphere over the Arctic Ocean and over land around the Arctic Ocean, which in turn causes higher temperatures of the water flowing into the Arctic Ocean from rivers.

Furthermore, jet stream changes can also cause additional heating of parts of the Pacific Ocean and the Atlantic Ocean.

[ click on images to enlarge ]
Above image shows that sea surface temperature anomalies off the East Coast of North America as high as 13.6°C or 24.4°F were recorded on December 18, 2019.

Ocean currents can bring huge amounts of heat into the Arctic Ocean, and this can be amplified due to cyclones speeding up the inflow of water from the Atlantic Ocean and the Pacific Ocean into the Arctic Ocean.


As above image shows, the temperature rise of the oceans on the Northern Hemisphere is accelerating. This constitutes a critical tipping point, i.e. there are indications that a rise of 1°C will result in most of the sea ice underneath the surface to disappear. This sea ice used to consume the inflow of warm, salty water from the Atlantic Ocean and the Pacific Ocean. So, while there may still be sea ice left at the surface, since low air temperatures will cause freezing of surface water, the latent heat buffer has gone.


As long as there is sea ice, this will keep absorbing heat as it melts, so the temperature will not rise at the sea surface. The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C.

The danger is that, as Arctic Ocean heating accelerates further, hot water will reach sediments at the Arctic Ocean seafloor and trigger massive methane eruptions, resulting in a huge abrupt global temperature rise. As discussed in an earlier post, a 3°C will likely suffice to cause extinction of humans.


Earlier this year, an Extinction Alert was issued, followed by a Stronger Extinction Alert.

In a rapid heating scenario:
  1. a strong 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.
[ from an earlier post ]

The precautionary principle calls for appropriate action when dangerous situations threaten to develop. How can we assess such danger? Risk is a combination of probability that something will eventuate and severity of the consequences. Regarding the risk, there is growing certainty that climate change is an existential threat, as discussed in a recent post. There's a third dimension, i.e. timescale. Imminence alone could make that a danger needs to be acted upon immediately, comprehensively and effectively. While questions may remain regarding probability, severity and timescale of the dangers associated with climate change, the precautionary principle should prevail and this should prompt for action, i.e. comprehensive and effective action to reduce damage is imperative and must be taken as soon as possible.

The image below gives a visual illustration of the danger.


Polynomial trendlines can point at imminent danger by showing that acceleration could eventuate in the near future, e.g. due to feedbacks. Polynomial trendlines can highlight such acceleration and thus warn about dangers that could otherwise be overlooked. This can make polynomial trendlines very valuable in climate change analysis. In the image below, the green linear trend and the blue polynomial trend are long-term trends (based on Jan.1880-Nov.2019 data), smoothing El Niño/La Niña variability, but the blue polynomial trend better highlights the recent temperature rise than the green linear trend does. The red short-term trend (based on Jan.2009-Nov.2019 data) has the highest R² (0.994) and highlights how El Niño could be the catalyst for huge methane eruptions from the Arctic Ocean, triggering a huge global temperature rise soon.


The image below, from an earlier post, explains the speed at which warming elements can strike, i.e. the rise could for a large part occur within years and in some cases within days and even immediately.


As the image below shows, peak methane levels as high as 2737 parts per billion (ppb) were recorded by the MetOp-2 satellite in the afternoon of December 20th, 2019, at 469 mb. Ominously, a large part of the atmosphere over the East Siberian Arctic Shelf (ESAS) is colored solid magenta, indicating methane levels above 1950 ppb.



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



Links

• NASA - GISS Surface Temperature Analysis (GISTEMP v4)
https://data.giss.nasa.gov/gistemp/maps/index_v4.html

• NOAA Northern Hemisphere ocean temperature anomalies through November 2019
https://www.ncdc.noaa.gov/cag/global/time-series/nhem/ocean/1/11/1880-2019

• NOAA - Monthly temperature anomalies versus El Niño
https://www.ncdc.noaa.gov/sotc/global/201911/supplemental/page-3

• 2020 El Nino could start 18°C temperature rise
https://arctic-news.blogspot.com/2019/11/2020-el-nino-could-start-18-degree-temperature-rise.html

• NOAA Arctic Report Card 2019
https://www.arctic.noaa.gov/Report-Card/Report-Card-2019

• Critical Tipping Point Crossed In July 2019
https://arctic-news.blogspot.com/2019/09/critical-tipping-point-crossed-in-july-2019.html

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• Accelerating greenhouse gas levels
https://arctic-news.blogspot.com/2019/11/accelerating-greenhouse-gas-levels.html

• Debate and Controversy
https://arctic-news.blogspot.com/p/debate.html

• Extinction Alert
https://arctic-news.blogspot.com/2019/02/extinction-alert.html

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

• Abrupt Warming - How Much And How Fast?
http://arctic-news.blogspot.com/2017/05/abrupt-warming-how-much-and-how-fast.html

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