Showing posts with label sea ice. Show all posts
Showing posts with label sea ice. Show all posts

Monday, March 24, 2025

Accelerating Temperature Rise

The Northern Hemisphere temperature was 12.86°C on March 19, 2025, a record daily high and 1.65°C higher than 1979-2000.
Very high temperature anomalies are forecast over the Arctic Ocean for November 2025. 


[ Nov 2025 temperature anomaly forecast ]
The image on the right shows the same forecast of temperature anomalies for November 2025, in this case with a Northern Hemisphere projection. Very high anomalies are visible over the Arctic Ocean, showing anomalies of 13°C, i.e. at the end of the scale, so anomalies may be even higher over some parts of the Arctic Ocean. 

What makes such high temperatures possible is a combination of conditions and mechanisms as described below. Some conditions have been building up for a long time, whereas some mechanisms can contribute to a very rapid acceleration of the temperature rise. 

1. ENSO - a new El Niño could emerge in 2026. The image below shows NOAA's forecast outlook issued March 30, 2025, with rising El Niño probabilities.


2. Sunspots - have long been far higher than predicted, while expected to reach their peak in the current cycle in July 2025. NOAA has meanwhile added new predictions based on a nonlinear curve fit to the observed monthly values for the sunspot number and F10.7 Radio Flux, updated every month as more observations become available.

3. Earth's Energy Imbalance - very high and rising, as illustrated by the image below by Leon Simons.

4. Greenhouse gases

High concentrations of greenhouse gases and other gases such as carbon monoxide result in high temperatures. The daily average carbon dioxide (CO₂) at Mauna Loa, Hawaii, was 430.60 parts per million (ppm) on March 7, 2025, the highest daily average on record. To find CO₂ levels this high back in history, one needs to go back millions of years, as illustrated by the image below, from an earlier post. 
What makes current conditions even more dire is that not only are concentrations of CO₂ very high, but the speed at which CO₂ is rising is also unprecedented, while additionally there has been an increase in total solar irradiance of ∼400 Wm⁻² since the formation of the Earth. 

Between 14 and 15 million years ago, the temperature in central Europe was 20°C higher than today, as illustrated by the image below (adapted from a 2020 study by Methner et al.).

[ from earlier post ]
Given today's very high CO₂ levels, why is the temperature in central Europe not 20°C higher today? It can take long for oceans to heat up due to their mass, while ice also acts as a buffer, consuming heat in the process of melting and ice can also reflect a lot of sunlight back into space, as long as there is ice present.

A trend, based on 2015-2024 annual data, points at 1200 ppm CO₂ getting crossed in the year 2032, as illustrated by the image below.

[ from an earlier post ]
The above trend illustrates that the clouds tipping point could get crossed in early 2032 due to rising CO₂ alone, which on its own could push temperatures up by an additional 8°C. The clouds tipping point is actually at 1200 ppm CO₂e, so when taking onto account growth of other greenhouse gases and further mechanisms, the tipping point could be crossed much earlier than in 2033.

Methane in the atmosphere could be doubled soon if a trend unfolds as depicted in the image below. A rapid rise is highlighted in the inset and reflected in the trend.

[ from earlier post ]
The trend points at a doubling of methane by March 2026. If the trend would continue, methane concentrations in the atmosphere would by September 2026 increase to more than triple the most recent value, and would increase to more than fourfold the October 2024 value by the end of 2026. 

A rise like the one depicted in the trend could eventuate as rising ocean heat destabilizes methane hydrates contained in sediments at the seafloor of the Arctic Ocean. The temperature rise in the Arctic would accelerate since the methane would have a huge immediate impact on temperatures over the Arctic and cause depletion of hydroxyl, of which there is very little in the atmosphere over the Arctic in the first place. Such a rise in methane would also cause dramatic increases in tropospheric ozone and in stratospheric water vapor. A large increase in methane over the Arctic would also trigger massive forest fires and tundra fires, devastating terrestrial permafrost and resulting in huge amounts of further emissions.

5. Sea surface temperatures

While it can take long for oceans to heat up due to their mass, sea surface temperatures can rise rapidly and what makes the situation worse is that as temperatures rise, stratification increases. 

Slowing down of the Atlantic meridional overturning circulation (AMOC) results in a huge amount of ocean heat accumulating in the North Atlantic. Much of the heat in the North Atlantic could soon be pushed abruptly into the Arctic Ocean, as storms can temporarily speed up currents strongly, carrying huge amounts of ocean heat with them into the Arctic Ocean. 
[ from earlier post ] 
The mechanism behind this has been described often in earlier posts and this page. Meanwhile, sea surface temperatures remain very high. The red trend on the image below points at a huge rise by 2026.

6. Less lower clouds - as temperatures rise, there is a decrease in lower clouds that have previously reflected a lot of sunlight back into space. A 2021 study finds that warming oceans cause fewer bright clouds to reflect sunlight into space, admitting even more energy into Earth's climate system.

[ Earthshine annual albedo anomaly expressed as reflected flux in W/m². CERES data. ] 
7. Reductions in cooling aerosols 

Reductions in sulfates and other cooling aerosols also result in albedo loss. Similarly, terpines from healthy trees can cause a lot of sunlight to be reflected back into space. Droughts, fires and deforestation can cause decreases in terpines. A recent study led by Annele Virtanen concludes that the indirect cooling effect of aerosols is at the higher end of the uncertainty range of IPCC AR6 and of satellite-derived forcing estimates.

8. More heating aerosols 

Heating aerosols such as soot are caused by road traffic, burning biomass for energy, burning wood for heat and forests fires. Such aerosols cause heat to remain in the atmosphere, while they also speed up the decline of sea ice and glaciers through albedo loss and growth of algae. 

9. Less sea ice and glaciers

Sea ice and glaciers have been in decline for many years and the decline may soon reach tipping points.
 
Arctic sea ice extent was 14.35 million km² on March 28, 2025, a record daily low for the time of year and 1.17 million km² lower than the extent in 2012 on this date. The comparison with extent in 2012 is important since Arctic sea ice extent was 3.18 million km² on September 16, 2012, an all-time low in this record dating back to 1981. A tipping point could be reached when sea ice falls below a critical threshold. 

[ Arctic-sea-ice extent, click on images to enlarge ]
A Blue Ocean Event could be declared when Arctic sea ice reaches or crosses a threshold of 1 million km² in extent. However, extent can include holes, gaps or cracks in the sea ice and melt ponds on top of the ice, all having a darker color than ice. By contrast, sea ice area is the total region covered by ice alone, making it a more critical measurement in regard to albedo than extent. Accordingly, the threshold for a Blue Ocean Event can be 1 million km² in area. 

Arctic sea ice area typically reaches its annual minimum about half September. Arctic sea ice area was only 2.24 million km² on September 12, 2012, i.e. 1.24 million km² away from a Blue Ocean Event. On March 19, 2025, Arctic sea ice area was 1.34 million km² lower than on March 19, 2012, as also discussed in an earlier post. Therefore, would there be such a difference about half September 2025, a Blue Ocean Event could be declared. 
The above image illustrates this, with the black dashed line indicating the threshold for a Blue Ocean Event and the red dotted line indicating Arctic sea ice area 1.34 million km² below what it was in 2012 for the respective date. 

Loss of albedo can occur due to retreat of sea ice, due to developments of cracks and holes in the sea ice, and due to discoloring of sea ice, which includes soot settling on the sea ice, growth of algae and ponding water on ice due to melting, as discussed in a recent study led by Philip Dreike. 

Loss of albedo can also occur due to loss of lower clouds and due to reduction in cooling aerosols (mechanism 3). Thawing of terrestrial permafrost is a further self-reinforcing feedback mechanisms that can cause more albedo loss as well as more emissions of carbon dioxide, methane and nitrous oxide, thus further accelerating the temperature rise in the Arctic. 

10. Latent heat buffer loss - as sea ice, permafrost and glaciers disappear.

Arctic sea ice decline comes not only with loss of albedo, but also with loss of the latent heat buffer that previously consumed a lot of heat entering the Arctic Ocean from the Atlantic Ocean and the Pacific Ocean. This mechanism constitutes a critical tipping point. 

     [ Arctic sea ice volume, click to enlarge ]
Loss of Arctic sea ice volume is illustrated by the image on the right, indicating that Arctic sea ice has become much thinner over the years.

Sea ice acts as a Buffer that previously consumed much incoming ocean heat. As temperatures rise, sea ice thins and the Buffer disappears.

The disappearance of the Buffer occurs at the same time as increasingly larger amounts of ocean heat are entering the Arctic Ocean from the North Atlantic Ocean and the Pacific Ocean. 

Consequently, the temperature of the water of the Arctic Ocean threatens to increase dramatically. 

         [ Arctic sea ice volume, click to enlarge ]
The image on the right illustrates the decline of Arctic sea ice volume over the years.

More heat in turn threatens to reach sediments at the seafloor of the Arctic Ocean and destabilize hydrates contained in the these sediments, resulting in eruptions of huge amounts of methane from hydrates as well as from methane stored in the form of free gas underneath these hydrates.  

The image below illustrates these mechanisms and their interaction and amplification, i.e. the thinning of Arctic sea ice, the increase in ocean heat and the threat of methane eruptions.
[ The Buffer is gone ]
Further mechanisms

There are many further mechanisms that jointly can rapidly speed up the temperature rise. Many of these mechanisms are self-reinforcing feedbacks that can interact and amplify each other, such as the formation of a freshwater lid at the surface of the North Atlantic, as also illustrated by the images above and below. 

[ formation of a freshwater lid at the surface of the North Atlantic ]
[ from Moistening Atmosphere ]
Global warming is causing more extreme weather events all around the world, and as temperatures keep rising, these events look set to become more extreme, i.e. hitting larger areas for longer, with higher frequency, more ubiquity and greater intensity.

[ from earlier post ]
For more on mechanisms behind a steep rise in temperature, also see this earlier post. 

Warnings ignored

A 2013 post issued a runaway global warming warning, i.e. that a 2°C global temperature rise could eventuate by 2024 and that a 10°C global temperature rise could eventuate by 2040. A post later in 2013 warned that the global temperature rise could continue beyond 20°C, with the added comment that it is in many respects irrelevant whether a temperature rise of 20°C will be reached in 2049, 2050 or 2051; the point is, as Sam Carana said in 2013, that we're facing a global temperature rise of potentially more than 20°C and that such a temperature rise would devastate Earth and drive most species (including human beings) to extinction well before such a temperature rise is reached.

A 2015 post shows an update of the 10°C global temperature rise image, as well as an image with estimates of the climate-related deaths that could occur would such a rise eventuate, while a post later in 2015 shows an update of the warning of a 20°C global temperature rise combined with the accumulated climate-related deaths in a single image (copy below). 

Sadly, politicians have long ignored warnings that a steep rise in temperature could occur and that this would result in a horrific number of associated deaths. In some respects, warnings were confusing and too conservative, e.g. the above image may have given the wrong impression that the temperature rise would be gradual and that we had until the year 2054 to get into action, whereas over the years indications have become ever stronger that a huge rise could take place within a few years, even within one year, as discussed below.

A warning was issued in 2016 that the temperature could rise by more than 10°C by 2026. The 2016 analysis is recreated below. The most recent NASA data gives the February 2016 temperature an anomaly of 1.35°C above 1951-1980. A number of non-linear trends can be calculated based on the anomalies, including one trend based on 2000-2016 data pointing at 10°C getting crossed by 2026 and another trend based on 1880-2016 data pointing at 1.5°C getting crossed in 2030, as shown by the chart and the details below.   

[ from the Extinction page ]
Three further trends can be calculated, based on different periods, two of them pointing at a rise of 10°C by 2017 and one trend pointing at a rise of 10°C by 2016, thus indicating that such a steep rise could happen very fast.

The clouds tipping point is mentioned above. A 2019 study concludes that crossing a tipping point of 1200 ppm CO₂e could cause the disappearance of marine stratus clouds, resulting in a global temperature rise of 8°C, which would come on top of the rise associated with greenhouse gases reaching 1200 ppm CO₂e. 

The image on the right illustrates how much conditions and mechanisms could each contribute to such a huge temperature rise. 

Very fast mechanisms include panic. As more people start to realize how dire the situation is and as they seek to occupy the last few habitable areas left, more people may stop showing up for work, resulting in a rapid loss of the aerosol masking effect, as industries that now co-emit cooling aerosols (such as sulfates) come to a grinding halt (mechanism 7 above).

As it becomes harder to obtain food and fuel for cooking and heating, and as the grid shuts down due to conflicts and people no longer showing up for work, many people may start collecting and burning more wood, decimating the forests that are left and resulting in more emissions that further speed up the temperature rise. 

As temperatures rise, huge fires could also break out in forests, peatlands, grassland and urban areas (including backyards, landfills and buildings, in particular warehouses containing flammable materials, chemicals and fluorinated gases), further contributing to more emissions that speed up the temperature rise.

As the likeliness of a huge and accelerating temperature rise, the severity of its impact, and the ubiquity and the imminence with which it will strike all become more manifest—the more sobering it is to realize that a mere 3°C rise may suffice to cause human extinction. Indeed, humans will likely go extinct with a 3°C rise and most life on Earth will disappear with a 5°C rise, as discussed in an earlier post and illustrated by the image below. 

[ from earlier post ]

According to a recent study lead by Richard Meade, many regions may soon experience heat and humidity levels that exceed the safe limits for human survival. "Our research provided important data supporting recent suggestions that the conditions under which humans can effectively regulate their body temperature are actually much lower than earlier models suggested," states co-author Glen Kenny.

Climate Emergency Declaration

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at this group.



Links

• Climate Reanalyzer
https://climatereanalyzer.org

• Tropical Tidbits
https://www.tropicaltidbits.com

• NOAA - ENSO: Recent Evolution, Current Status and Predictions - 31 March 2025
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

• Leon Simons - Earth's Energy Imbalance 
https://bsky.app/profile/leonsimons.bsky.social/post/3llcffaa65s2d

• High sensitivity of cloud formation to aerosol changes - by Annele Virtanen et al. (2025)
https://www.nature.com/articles/s41561-025-01662-y
discussed on facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10162536396379679

• Arctic and Antarctic Data Archive System (ADS) of the National Institute of Polar Research of Japan
https://ads.nipr.ac.jp

• Kevin Pluck - seaice.visuals.earth
https://seaice.visuals.earth

• Danish Meteorological Institute - Arctic sea ice volume and thickness
https://ocean.dmi.dk/arctic/icethickness/thk.uk.php

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

• Broadband radiometric measurements from GPS satellites reveal summertime Arctic Ocean Albedo decreases more rapidly than sea ice recedes - by Philip Dreike et al. 
https://www.nature.com/articles/s41598-023-39877-x
• El Nino in 2025?
https://arctic-news.blogspot.com/2025/03/el-nino-in-2025.html

• The Clouds Feedback and the Clouds Tipping Point
https://arctic-news.blogspot.com/p/clouds-feedback.html

• Mechanisms behind a steep rise in temperature

• How much will temperatures rise? (10°C rise image)

• Arctic Methane Impact (20°C rise image)

• Temperature rise (updated 10°C rise image)

• Methane Levels Early 2015 (updated 20°C rise image)

• Validating new limits for human thermoregulation - by Robert Meade et al. (2025) 
Posted by at
Labels: , , , ,

Monday, March 17, 2025

Arctic Blue Ocean Event 2025?

Arctic sea ice area 

Arctic sea ice area has been at a record daily low since the start of February 2025. 

Arctic sea ice area was 1.34 million km² lower on March 19, 2025, compared to March 19, 2012. The comparison with the year 2012 is important, since Arctic sea ice area reached its lowest minimum in 2012. Arctic sea ice area was only 2.24 million km² on September 12, 2012, i.e. 1.24 million km² above a Blue Ocean Event. 

The size of the sea ice can be measured either in extent or in area. What is the difference between sea ice area and extent? Extent is the total region with at least 15% sea ice cover. Extent can include holes or cracks in the sea ice and melt ponds on top of the ice, all having a darker color than ice. Sea ice area is the total region covered by ice alone. 

Blue Ocean Event (BOE)

A Blue Ocean Event (BOE) occurs when the size of the sea ice falls to 1 million km² or less, which could occur in Summer 2025 in the Northern Hemisphere for Arctic sea ice. If the difference between 2012 and 2025 continues to be as large as it is now, there will be a Blue Ocean Event in September 2025. 

A BOE is often defined as crossing a tipping point that is crossed when sea ice reaches or falls below 1 million km² in extent. However, it make more sense to look at sea ice area, rather than at sea ice extent, since sea ice area is a more critical measure in regard to albedo. Loss of sea ice area (and thus of albedo) is a self-reinforcing feedback that causes the temperature to rise, resulting in further melting of sea ice and thus further accelerating the temperature rise. 

A BOE occurs when the size of the sea ice falls to 1 million km² or less, which could occur in Summer 2025 in the Northern Hemisphere for Arctic sea ice. Arctic sea ice area was only 1.24 million km² above a BOE on September 12, 2012. If the difference between 2012 and 2025 continues to be as large as it is now, there will be a BOE in September 2025. 

Arctic sea ice volume and thickness

Volume and thickness are two further measures to assess the health of Arctic sea ice, and they are critical in regard to the latent heat buffer, which decreases as sea ice, permafrost and glaciers disappear.

Latent heat is energy associated with a phase change, such as the energy consumed when ice turns into water. During a phase change, the temperature remains constant. As long as there is ice, additional heat will be absorbed by the process of ice turning into water, so the temperature doesn't rise at the 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 energy required to melt a volume of ice can raise the temperature of the same volume of rock by as much as 150ºC.

Warmer water flowing into the Arctic Ocean causes Arctic sea ice to lose thickness and thus volume, diminishing its capacity to act as a buffer that consumes ocean heat entering the Arctic Ocean from the North Atlantic. This means that - as sea ice thickness decreases - a lot of incoming ocean heat can no longer be consumed by melting the sea ice from below, and the heat will therefore contribute to higher temperatures of the water of the Arctic Ocean. Similarly, there is a point beyond which thawing of permafrost on land and melting of glaciers can no longer consume heat, and all further heat will instead warm up the surface.
[ from earlier post ]
[ Arctic sea ice volume, click to enlarge ]
Abrupt seafloor methane eruptions

The image on the right shows that Arctic sea ice volume has been at a record daily low for more than a year, reflecting loss of the latent heat buffer. 

Loss of the latent heat buffer constitutes a tipping point. Beyond a certain point, further ocean heat arriving in the Arctic Ocean from the Atlantic Ocean and the Pacific Ocean will no longer be able to be consumed by melting sea ice from below. 

Further incoming heat therefore threatens to instead reach the seafloor of the Arctic Ocean and destabilize methane hydrates contained in sediments at the seafloor, resulting in eruptions of huge amounts of methane, in turn threatening increased loss of permafrost, resulting in additional emissions, as illustrated by the above image.

The danger is especially large in the East Siberian Arctic Shelf (ESAS), which contains huge amounts of methane and which is hit strongly by the temperature rise. The image below shows that high February 2025 sea surface temperature anomalies are present in the Arctic Ocean, including over ESAS. 


The bathymetry map in the right panel of above image shows how shallow seas in the Arctic Ocean can be. The water over the ESAS is quite shallow, making that the water can warm up very quickly during summer heat peaks and heat can reach the seafloor, which comes with the risk that heat will penetrate cracks in sediments at the seafloor. Melting of ice in such cracks can lead to abrupt destabilization of methane hydrates contained in sediments.

[ from earlier post, click on images to enlarge ]

Large abrupt methane releases will quickly deplete the oxygen in shallow waters, making it harder for microbes to break down the methane, while methane rising through waters that are shallow can enter the atmosphere very quickly.

The situation is extremely dangerous, given the vast amounts of methane present in sediments in the ESAS, given the high global warming potential (GWP) of methane immediately following its release and given that over the Arctic there is very little hydroxyl in the air to break down the methane.

[ from earlier post ]


High temperatures

On March 20, 2025, the temperature was 14.29°C (57.72°F), an anomaly of 0.78°C (1.4°F) above 1991-2020 and the highest daily temperature on record for this day of the year. It is significant that this record was reached despite the presence of La Niña conditions that suppress the temperature. 


ENSO variations (El Niño/La Niña/neutral) are indicated by the color of the shading. El Niño and La Niña are opposite phases of a natural climate pattern across the tropical Pacific Ocean that swings back and forth every 3-7 years on average, so a period of three years can suffice to reflect this pattern. The graph covers a period of roughly 3 years (end 2022 to end 2025) and is based on 829 daily data (December 13, 2022, to March 20, 2025). 

The above image shows two trends that warn that the temperature continues to rise and that the rise is accelerating. The black linear trend warns about a rise of 0.5°C over a time span of roughly 3 years (end 2022 to end 2025), a much steeper rise than the 1.1°C rise over the 81 years between 1941 and 2022. The red non-linear trend warns that further acceleration of the temperature rise could result in a rise exceeding 2°C over three years.

Both trends indicate acceleration of the temperature rise, despite the presence of La Niña conditions. The black trend is a straight line, while the red non-linear trend can bend and thus follow short-term variables more closely, such as ENSO variations (El Niño/La Niña) and sunspots, and it can also warn that further mechanisms can jointly speed up the temperature rise very rapidly, as discussed in many earlier posts such as this one.


NOAA doesn't expect a new El Niño to emerge soon (image above), which makes it even more significant that temperature anomalies currently are this high. One of the mechanisms that is pushing up temperatures is albedo loss, partly due to low sea ice. The image below shows that the global sea ice area has been at a record daily low since the start of February 2025. The associated albedo loss constitutes an important self-reinforcing feedback mechanism accelerating the temperature rise.


Why is sea ice loss causing the temperature to rise? Sea ice loss comes with loss of albedo (reflectivity), resulting in less sunlight to get reflected back into space and instead to get absorbed at the surface. Sea ice loss also comes with loss of the latent heat buffer, as discussed above. Albedo loss can also occur due to loss of lower clouds and reductions in cooling aerosols. Also have a look at feedbacks for more details. 

Meanwhile, the Northern Hemisphere reached a temperature of 12.32°C on March 14, 2025, a record daily high and 1.59°C higher than 1979-2000.
Ominously, very high temperature anomalies are forecast over the Arctic Ocean for November 2025.

[ Very high temperature anomalies forecast over Arctic Ocean, from earlier post ]
Further mechanisms accelerating the temperature rise

A recent analysis led by James Curran concludes that the rate of natural sequestration of CO₂ from the atmosphere by the terrestrial biosphere peaked in 2008. Natural sequestration is now declining by 0.25% per year. A recent analysis led by Rongbo Dai concludes that phytoplankton is reduced due to ocean acidification and stratification. 

Concentration of CO₂ in the atmosphere will rise as sinks turn into sources. Furthermore, more emissions can be expected from seafloor methane hydrate eruptions, from thawing permafrost, from flooded areas, and from fires (including fires in forests, peatland, grassland, urban waste in backyards and landfills, and fires in buildings - especially warehouses that contain flammable materials, chemicals and fluorinated gases). Mechanisms that are accelerating the temperature rise are discussed in this earlier post.

Human extinction at 3°C

If the temperature does indeed keep rising rapidly, the anomaly compared to pre-industrial may soon be higher than 3°C, implying that humans are already functionally extinct, especially if no decisive, comprehensive and effective action is taken.

Analysis by Shona and Bradshaw (2019) finds that, due to co-extinction, global biodiversity collapse occurs at around 5°C heating, as discussed in this 2019 post. The post adds the warning that a rise of more than 5°C could happen within a decade, possibly by 2026, and that humans who depend on many other species will likely go extinct with a 3°C rise.


A recent analysis led by Joseph Williamson concludes that many species that live together appear to share remarkably similar thermal limits. That is to say, individuals of different species can tolerate temperatures up to similar points. This is deeply concerning as it suggests that, as ecosystems warm due to climate change, species will disappear from an ecosystem at the same time rather than gradually, resulting in sudden biodiversity loss. It also means that ecosystems may exhibit few symptoms of heat stress before a threshold of warming is passed and catastrophic losses occur.

A recent analysis led by Thiago Gonçalves-Souza concludes that species turnover does not rescue biodiversity in fragmented landscapes.

Climate Emergency Declaration

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at this group.



Links

• Kevin Pluck - seaice.visuals.earth
https://seaice.visuals.earth 

• NSIDC - What is the difference between sea ice area and extent?
https://nsidc.org/learn/ask-scientist/what-difference-between-sea-ice-area-and-extent

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

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

• Heat flux forecast to enter Arctic early February 2025
https://arctic-news.blogspot.com/2025/01/heat-flux-forecast-to-enter-arctic-early-february-2025.html

• Danish Meteorological Institute - daily temperature Arctic
https://ocean.dmi.dk/arctic/meant80n.uk.php

• Danish Meteorological Institute - Arctic sea ice volume and thickness
https://ocean.dmi.dk/arctic/icethickness/thk.uk.php

• Arctic and Antarctic Data Archive System (ADS) of the National Institute of Polar Research of Japan
https://ads.nipr.ac.jp

• Copernicus
https://pulse.climate.copernicus.eu

• NOAA - ENSO: Recent Evolution, Current Status and Predictions (17 March 2025)
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

• NOAA - El Niño and La Niña: Frequently asked questions
• Climate Reanalyzer
https://climatereanalyzer.org

• Natural sequestration of carbon dioxide is in decline: climate change will accelerate - by James Curran et al. 
https://rmets.onlinelibrary.wiley.com/doi/10.1002/wea.7668
discussed on facebook at: 
• Eukaryotic phytoplankton drive a decrease in primary production in response to elevated CO₂ in the tropical and subtropical oceans - by Rongbo Dai et al.
discussed on facebook at: 

• University of Bremen - sea ice
https://seaice.uni-bremen.de/start

• Tropical Tidbits
https://www.tropicaltidbits.com

• When will we die?
https://arctic-news.blogspot.com/2019/06/when-will-we-die.html

• Species turnover does not rescue biodiversity in fragmented landscapes - by Thiago Gonçalves-Souza et al.
https://www.nature.com/articles/s41586-025-08688-7
discussed on facebook at: 

For comments and discussion of this post on facebook, click below.




Posted by at
Labels: , , , , , , , , ,

Wednesday, March 5, 2025

How to respond to the threat of a huge temperature rise


The above image illustrates the threat of a huge temperature rise. The red trendline warns that the temperature could increase at a terrifying speed soon. 

Mechanisms contributing to a huge acceleration in the temperature rise

At first glance, the data may seem to disagree with such a rise, temperature anomalies even appear to have come down recently. However, a closer look at the shading in the image highlights the difference between El Niño conditions (pink shading) and La Niña conditions (blue shading). An El Niño pushes up temperatures, whereas La Niña suppresses temperatures. 

We're currently in a La Niña, so temperatures are suppressed, but this is predicted to end soon. NOAA predicts a transition away from La Niña to occur next month, as illustrated by the image below. 


Later this year, a new El Niño may emerge, which may push up the temperature dramatically. 

Importantly, ENSO is only one out of ten mechanisms that could jointly cause the temperature rise to accelerate dramatically in a matter of months, as described in a previous post and with further details for some of them following below. 

[ SSTA and wind, click to enlarge ]
An important mechanism driving up the temperature is rising ocean heat. The image on the right shows a sea surface temperature anomaly of 9.7°C (17.4°F) versus 1981-2011 at the green circle south of Africa on March 5, 2025.

The image also shows the impact of high sea surface temperature anomalies (SSTA) on the Jet Stream (250 hPa), with the Jet Stream going circular in two areas with high sea surface temperature anomalies.

These mechanisms interact and can also amplify each other dramatically, in particular rising ocean heat, deformation of the Jet Stream and shrinking sea ice.

[ click on image to enlarge ]
As the above compilation image shows, the Jet Stream (250 hPa) is forecast to go circular in three areas on the Northern Hemisphere and reach speeds as high as 216 km/h (134 mph, circle) over Greenland on March 11, 2025 06 UTC, pushing a lot of heat toward Baffin Bay (left panel). As a result, temperatures over Baffin Bay are forecast to be as much as 30°C higher than 1979-2000 (right panel).

[ Arctic sea ice volume, click to enlarge ]
The above image shows that Arctic sea ice area has been at a record daily low since the start of February 2025.  Importantly, Arctic sea ice volume has been at a record daily low for more than a year, as illustrated by the image on the right. 

There has been little to no sunshine over the Arctic over the past few months (Spring has only just started), so rising ocean heat is obviously contributing strongly to this extremely low Arctic sea ice volume. 

A recent study lead by Sohail describes how cold, fresh meltwater from Antarctica migrates north, filling the deep ocean as it goes and causing changes to the density structure of the ocean, leading to an overall slowdown in the current. 

[ from Sohail et al. (2025) ]
The above image, from the study, depicts how this could lead to reduced Antarctic Bottom Water. One danger is that less ocean heat reaching the seafloor will result in more heat accumulating at the surface and in the atmosphere, as discussed in an earlier post. A weaker current may also allow more warm water to penetrate southwards, and faster ice melting could then lead to further weakening of the current, commencing a vicious spiral of current slowdown, says Taimoor Sohail.

As illustrated by the image below, global sea ice area has been at a record daily low since February 2025. If this situation continues, a huge amount of sunlight that was previously reflected back into space will instead be absorbed by the surface—increasingly so on the Northern Hemisphere over the coming months, with the change in seasons. 

The loss of Earth's albedo (reflectivity) over the years is illustrated by the graph below, by Eliot Jacobson.

[ Image by Eliot Jacobson ]
What to expect

Some may question whether the temperature could rise as high as depicted in the red trendline in the image at the top. Others may question whether such a huge temperature rise could occur this rapidly. They all miss the point. The point is that a huge rise may occur soon and that politicians are taking little to no action. 

As the likeliness of a huge and accelerating temperature rise, the severity of its impact, and the ubiquity and the imminence with which it will strike all become more manifest—the more sobering it is to realize that a mere 3°C rise may suffice to cause human extinction.

A state of emergency is typically declared only after a disaster hits a specific area. Increasingly though, extreme weather events can be expected to occur more frequently and we must not only look at the intensity and severity at which one specific place is hit by an event, but we must also incorporate ubiquity and imminence in our response. As temperatures rise, more extreme weather events will occur with greater intensity, more frequently, over larger areas, with longer duration and they will become more ubiquitous and follow each other up with increasing if not accelerating rapidity.

How to repond

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at this group.



Links

• Copernicus
https://climate.copernicus.eu

• NOAA - ENSO evolution and El Niño status 

• Danish Meteorological Institute - Arctic sea ice volume and thickness
https://ocean.dmi.dk/arctic/icethickness/thk.uk.php

• Decline of Antarctic Circumpolar Current due to polar ocean freshening - by Taimoor Sohail et al. https://iopscience.iop.org/article/10.1088/1748-9326/adb31c
discussed on facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10162412290944679

• Kevin Pluck - seaice.visuals.earth
https://seaice.visuals.earth

• Climate Reanalyzer
https://climatereanalyzer.org

• nullschool.net
https://earth.nullschool.net

Posted by at
Labels: , , , , , ,