Monday, December 9, 2024

Did a Terminal Temperature Acceleration Event start in December 2024?

Terminal Temperature Acceleration?

On December 30, 2024, the temperature was at a record high for the time of year. Given that La Niña suppresses temperatures, the question is what is driving up the temperature. 


The red dots in the above image are Copernicus ERA5 global daily mean near-surface (2m) air temperature anomalies December 13, 2022 through December 30, 2024, compared to a 1991-2020 base (left vertical axis) and a 1901-1930 base (right vertical axis). 

The pink shading indicates El Niño (end May 2023 to early May 2024) and the blue shading indicates ENSO-neutral conditions and La Niña. The gray shading indicates uncertainty regarding ENSO and the potential for Terminal Temperature Acceleration. 

Two trends are added based on these data (red dots). The linear trend (black) shows a steady, rapid rise. The non-linear trend (red) better follows variable mechanisms such as El Niño and sunspots, and the red trend indicates that a Terminal Temperature Acceleration Event may have started end December 2024 (the area with the grey shading). 

The grey shading may seem to be a grey area, but note that as La Niña will gradually decline in the course of 2025 (as predicted), the suppressing impact that La Niña has on temperatures will disappear and the prospect for a steep rise can be expected to become more manifest, as indicated by the red trend. Furthermore, as discussed below and in earlier posts such as this one, there are additional mechanisms that jointly and through their interaction increase the potential for a steep temperature rise in the course of 2025. 

Pre-industrial base
[ click on images to enlarge ]

The above comparison image illustrates that the use of a 1901-1930 base instead of the default Copernicus 1991-2020 base comes with an adjustment of the temperature anomaly of 0.91°C. Note that neither of these bases are pre-industrial. As discussed at the pre-industrial page, using pre-industrial as a base requires a further adjustment of as much as an additional 0.99°C, which would correspond with a total temperature anomaly for the year 2023 of as much as 2.47°C.

The image below, created with NASA data through November 2024 while using a 1903-1924 custom base, illustrates that the monthly temperature anomaly has been more than 1.5°C above this base for 17 consecutive months (from July 2023 through November 2024). The red line shows a trend (2-year Lowess Smoothing) associated with recent data and the trend indicates that the anomaly is rising.


Note that the 1903-1924 base is not pre-industrial. When using a genuinely pre-industrial base, anomalies such as the above-mentioned 1.89°C for February 2024 will exceed 2°C, as discussed at the pre-industrial page.

El Niño–Southern Oscillation (ENSO)

The current La Niña is predicted to be weak and short-lived, as illustrated by the image below, from NOAA, with probabilities for an El Niño getting progressively higher in the course of 2025.


The image below, adapted from NOAA, confirms that La Niña is expected to persist through February-April 2025.


The image below, adapted from NOAA, shows monthly temperature anomalies versus El Niño/La Niña through November 2024.


Since a La Niña typically suppresses temperatures, the question arises as to what is causing the temperatures to remain high. The strength of La Niña is also discussed here and here on facebook.

Temperature maps November 2024


As the images above and below show, temperature anomalies in November 2024 were particularly high in the Arctic.


The image on the right also shows temperature anomalies versus 1951-1980 for November 2024 over the Arctic, this time using NCEP/NCAR data.

Keep in mind that, while the 1951-1980 base for the above maps is NASA's default base, none of the bases used in the above images is pre-industrial. As said, anomalies from a pre-industrial base are higher.

Carbon dioxide keeps rising rapidly

Carbon dioxide (CO₂) keeps rising rapidly. On December 31, 2024, the CO₂ concentration reached 427.16 parts per million (ppm) at Mauna Loa, Hawaii, after reaching an earlier peak of 427.85 ppm on December 11, 2024, as illustrated by the image below, adapted from NOAA. 

The mean annual carbon dioxide was 424.61 ppm in 2024, an increase of 3.53 ppm compared to 2023 and the highest annual growth on record. This record high growth rate indicates that emissions of carbon dioxide are increasing while carbon sinks are weakening at the same time.  


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


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 growth of other greenhouse gases and further mechanisms is taken into account, the tipping point could be crossed much earlier than in 2033. 

Mechanisms behind accelerated temperature rise

Research led by Helge Goessling suggests that global warming itself may be reducing the number of low clouds, resulting in less sunlight getting reflected back into space. “If a large part of the decline in albedo is indeed due to feedbacks between global warming and low clouds, as some climate models indicate, we should expect rather intense warming in the future,” Helge Goessling warns.

A Terminal Temperature Acceleration Event may occur soon due to a number of mechanisms, incl.:
- falling sea ice volume causing hydrates to destabilize, resulting in methane eruptions
- falling albedo as a result of reduction in sea ice extent
- falling albedo as a result of a reduction in lower clouds      
- El Niño developing in the course of 2025
- sunspots reaching a maximum in the current cycle (predicted to occur July 2025)
- reductions in sulfur aerosols combined with an increase in black carbon and brown carbon 
- less ocean heat reaching deeper parts of the ocean as a result of changes in ocean currents
  (see below)

Atlantic Meridional Overturning Circulation (AMOC)
[ Zonal and meridional flow, from Freshwater lid ]
[ Gulf Stream, from Freshwater lid ]
[ AMOC, from Freshwater lid ]
[ Global Ocean Circulation System, from Freshwater lid ]

For more details on the above mechanisms also have a look at the post Double Blue Ocean Event 2025?, which warns about the potential for dramatic ice decline at both poles.

Antarctic sea ice


[ Antarctic sea ice thickness in cm ]
The above compilation of four images by the University of Bremen and the image on the right illustrate the decline in Antarctic sea ice thickness between August 27, 2024, and December 29, 2024.

Changes to ocean currents can cause more heat 
to accumulate at the ocean surface, resulting in more Antarctic sea ice melting from below and losing thickness. Where the temperature of the (saline) ocean water rises above -1.8°C (28.7°F), the sea ice will start melting away. 

The image below shows the Southern Hemisphere 
on December 22, 2024, when the sea surface temperature off the coast of East Antarctica was 0.1°C at the green circle (image left), an anomaly from 1981-2011 of 1.4°C (image right).


Arctic sea ice

In 2023, North Atlantic (0-60°N 0-80°W) sea surface temperature anomalies vs 1882-2010 rose strongly in line with El Niño. In 2024, temperature anomalies remained consistently high, despite La Niña conditions present at the end of 2024.


As illustrated by the images above and below, the North Atlantic sea surface temperature was 21.31°C on December 26, 2024, a record high for the time of year and 1.03°C above 1982-2010. For much of 2024, the anomaly has been higher than it was in 2023.


As discussed in earlier posts, Arctic sea ice has also become very thin, diminishing its capacity to act as a buffer that consumes ocean heat entering the Arctic Ocean from the North Atlantic. Of the combination image below, the top part is adapted from an image by the Danish Meteorological Institute and this illustrates that both maximum- and minimum Arctic sea ice volume reached a new record low in September 2024. Markers for September (red) and April (blue) correspond with the year's minimum- and maximum volume.


One out of many dangers of rising temperatures is that, as Arctic sea ice keeps declining in volume while the water of the North Atlantic keeps heating up, more heat will reach the seafloor of the Arctic Ocean, destabilizing methane hydrates contained in sediments at the seafloor and resulting in eruptions of huge amounts of methane, as illustrated by the bottom part of the above combination image. 

The danger is particularly large in the East Siberian Arctic shelf (ESAS), where the sea has a mean depth of less than 50 m. This shallow depth makes it easier for heat to reach the seafloor and destabilize hydrates contained in sediments at the seafloor, resulting in methane eruptions. This shallow depth also means there is less opportunity for the methane to be broken down while rising in the water. 

As illustrated by the image on the right, Arctic sea ice volume was at a record low for the time of year on December 31, 2024.

On December 29, 2024, Arctic sea ice extent was at a record low for the time of year, as illustrated by the image below, adapted from ads.nipr.ac.jp. 






The above image shows Arctic sea ice extent in December, a month when Arctic sea ice is growing in extent. The red line shows 2024 sea ice extent through December 29, 2024. Dots mark Arctic sea ice extent on December 29 for the respective year. Arctic sea ice was at a record daily low extent on December 29, 2024.

The image on the right, adapted from NSIDC.org, shows that Arctic sea ice extent was 12.195 million million km² on December 30, 2024, a record low for this date.

The record low daily Arctic sea ice volume and extent occur under La Niña conditions that suppress temperatures. 

As said, as La Niña will gradually decline in the course of 2025 (as predicted), the suppressing impact that La Niña has on temperatures will disappear and the prospect for a steep temperature rise can be expected to become more manifest, with rapid decline of Arctic sea ice constituting just one out of many feedback mechanisms further accelerating the temperature rise.

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



• Recent global temperature surge intensified by record-low planetary albedo - by Helge Goessling et al.
https://www.science.org/doi/10.1126/science.adq7280
also discussed on facebook at:
https://www.facebook.com/groups/arcticnews/posts/10162210409914679


• NOAA - ENSO: Recent Evolution, Current Status and Predictions - 30 December 2024 update
also discussed on facebook at:

• NOAA - Monthly Temperature Anomalies Versus El Niño/La Niña
https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/202411/supplemental/page-4




• NOAA - Global Monitoring Laboratory - monthly trends in CO2
https://gml.noaa.gov/ccgg/trends/monthly.html


• 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

• NSIDC - Charctic Interactive Sea Ice Graph

• Cold freshwater lid on North Atlantic
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Tuesday, November 5, 2024

Sea ice alert

Sea ice

[ click on images to enlarge ]
The above image shows Arctic sea ice extent from November 5 to December 24, a period when Arctic sea ice is growing in extent. The red line shows 2024 sea ice extent through November 23, 2024. Dots mark Arctic sea ice extent on November 23 for the respective year. On November 23, Arctic sea ice extent was lower only in 2016, which is worrying, since El Niño conditions were dominant in 2016, whereas La Niña conditions are now dominant. 

The current La Niña is predicted to be weak and short-lived, as illustrated by the image below, from NOAA. 


The image below shows NOAA monthly temperature anomalies versus El Niño through October 2024. 


The image below shows Antarctic sea ice extent during the months September and October, highlighting extent in 2023 and 2024, as compared to extent averages in previous decades.

As illustrated by the above image, Antarctic sea ice extent in September and October 2023 & 2024 was much lower than in previous decades, a huge difference that occurred during a period when little or no sunlight was reaching Antarctic sea ice. On November 9, 2024, Antarctic sea ice extent was 14.99 million km², a record low for the time of year.

Global sea ice typically reaches its annual maximum extent around this time of year, as Arctic sea ice expands in extent. On November 9, 2024, global sea ice extent was 23.34 million km², a record low for the time of year and well below the 24.15 million km² on November 9, 2023. 


Higher ocean heat in combination with higher air temperatures over the Arctic Ocean are two drivers behind the current slow growth in Arctic sea ice extent, which is in turn keeping global sea ice extent low.

[ from earlier post ]
Record low Arctic sea ice extent of 3.387 million km² was reached on September 17, 2012 (image below left). 

The fact that this has remained the record low for more than a dozen years may be caused by slowing down of the Atlantic meridional overturning circulation (AMOC) resulting in less ocean heat reaching the highest latitudes North, while more ocean heat instead is accumulating in the North Atlantic. 

At the same time, rising ocean heat has caused a steady decrease in the volume of Arctic sea ice, as illustrated by the image on the right.  

The danger is that as more heat accumulates in the North Atlantic, some of it can get abruptly pushed into the Arctic Ocean along the path of the Gulf Stream due to ever stronger hurricanes and formation of a freshwater lid at the surface of the North Atlantic, resulting in more ocean heat reaching the seafloor of the Arctic Ocean and destabilizing sediments that contain hydrates holding huge amounts of methane, in turn resulting in huge amounts of methane abruptly entering the atmosphere. 

[ click on images to enlarge ]

Antarctic sea ice reached a record minimum extent of 1.788 million km² on February 21, 2023 (above image right). The increasingly low Antarctic sea ice extent of the past few years may have been caused by slowing down of AMOC causing less vertical mixing in the Southern Ocean, resulting in more heat  accumulating at the surface that melted more Antarctic sea ice, with numerous feedbacks reinforcing the sea ice decline.

Since the minimum extent of Antarctic sea ice is much lower than the minimum sea ice extent in the Arctic, it may well be that a Blue Ocean Event (BOE) will occur in the Southern Hemisphere, before occurring in the Northern Hemisphere. 

A double Blue Ocean Event could occur in 2025. Both Antarctic sea ice and Arctic sea ice could virtually disappear in 2025. A BOE occurs when sea ice extent falls to 1 million km² or less, which could occur early 2025 for Antarctic sea ice and in Summer 2025 in the Northern Hemisphere for Arctic sea ice.

The compilation of four images by the University of Bremen below illustrates the decline in Antarctic sea ice thickness from August 27, 2024, to November 28, 2024.


An Antarctic Blue Ocean Event in early 2025 would have terrifying consequences; it would rapidly and dramatically drive up global temperatures and threaten to unleash a double Blue Ocean Event in 2025.  

The image and the right and below illustrate the ocean heat that is accumulating at the surface of the Atlantic Ocean.

On November 30, 2024, the sea surface temperature of the US Atlantic was as high as 31.1°C.

On November 28, 2024, the sea surface temperature was 27.1°C in the Gulf of Mexico, 2.07°C higher than 1982-2010.  

[ click on images to enlarge ]

Historic rise: more than 1.5°C above 1903-1924 for 16 consecutive months 


The above image, created with NASA data through October 2024 while using a 1903-1924 custom base, illustrates that the monthly temperature anomaly has been more than 1.5°C above this base for 16 consecutive months (from July 2023 through October 2024). The red line shows a trend (2-year Lowess Smoothing) associated with recent data and the trend indicates that the anomaly is rising. 

How appropriate is the use of a 1903-1924 base? Using a different base can make a lot of difference. As illustrated by the image below, the temperature anomaly for February 2024 can be as high as 1.89°C when using a 1904-1911 base. 


A recent study argues that existing estimates of ocean temperatures for the period 1900–1930 are too cold. When adjusting ocean data upward, the anomaly compared to this period would come down, so in order not to downplay the temperature rise, it's important to put this into perspective.

As the image below shows, differences between ocean and land data for the period 1880-1898 are even larger, which is important since the period 1880-1898 is part of the period that the IPCC has selected as pre-industrial base. 


While adjusting ocean data for 1921-1943 makes sense, it is even more important to use the most appropriate base as pre-industrial and to adjust the temperature rise from pre-industrial accordingly. When using a genuinely pre-industrial base, anomalies such as the above-mentioned 1.89°C for February 2024 will exceed 2°C, as discussed at the pre-industrial page. 

[ click on images to enlarge ]
The map on the right with October 2024 temperature anomalies from 1951-1980 based on NCEP data shows high polar anomalies.   

Similarly, the map below with October 2024 temperature anomalies from 1951-1980 based on ERA5 data shows high polar anomalies.  

The 1951-1980 base for the maps is NASA's default base, but neither 1951-1980 nor the above 1903-1924 is pre-industrial. As said, anomalies from a pre-industrial base are higher.


The rise to come

As illustrated by the image below, adapted from Copernicus, the temperature in 2024 has been higher than it was in 2023 for most of the year. On November 23, 2024, the temperature was 13.86°C, the highest on record for the time of year. 


The image below shows temperature anomalies versus 1991-2020 from early 2023 through November 23, 2024. Trends added to the ERA5 data show that the anomaly has been rising for almost 18 consecutive months, i.e. since the start of El Niño (June 2023, pink shading), during ENSO-neutral conditions (from May 2024, blue shading) and into La Niña (from October 2024, also blue shading).


The black linear trend shows a huge rise. The red trend is closer in line with variability such as resulting from ENSO and sunspots. The red trend indicates very high anomalies and a steep further rise into 2025, in line with the next El Niño becoming dominant in the second half of 2025, coinciding with very high sunspots.

Self-amplifying feedbacks, crossing of tipping points and further developments (such as loss of the aerosol masking effect) can all contribute to further accelerate the temperature rise through 2026, resulting in a rise from pre-industrial of more than 10°C, while in the process causing the clouds tipping point to get crossed that can push up the temperature rise by a further 8°C, as discussed in earlier posts such as this one.

Jet Stream distortion

As a result of the narrowing temperature difference between the Arctic and the Tropics, the Jet Stream gets distorted. The image below shows a distorted Jet Stream (250 hPa) over the North Atlantic on November 11, 2024. 


Precipitation

The image below shows an atmospheric river stretched out over the North Atlantic from the Tropics to the Arctic with high rainfall over the North Atlantic and snowfall over Greenland on November 11, 2024.  


Water vapor

The image below shows a forecast for November 12, 2024, with precipitable water anomalies at the high end of the scale over the Arctic Ocean. 

Feedbacks

The image below illustrates how multiple feedbacks can interact and jointly contribute to further acceleration of the temperature rise.

[ from earlier post ]

There are many feedbacks and other mechanisms active and they are interacting on top of driving up temperatures individually. 

Albedo change is a feedback that can have a huge impact. The currently very low global sea ice extent is a self-reinforcing feedback, as it results in less sunlight getting reflected back into space and more heat getting absorbed by oceans.

Extra water vapor is another self-reinfocing feedback, since water vapor is a potent greenhouse gas. 

These are just some of the feedbacks that can contribute to further acceleration of the temperature rise, as discussed in an earlier post.

Carbon dioxide keeps rising

The above image shows carbon dioxide on November 12, 2024 - forecast for 03 UTC by Copernicus. The graph at the bottom of the image shows monthly carbon dioxide exceeding 425 ppb in October 2024 at Mauna Lao, Hawaii, based on NOAA data with trend added.


The images on the right, adapted from Climate Reanalyzer, shows the total precipitation standardized anomaly over the past few years. The top image shows the anomaly in Brazil.

The image underneath on the right shows the anomaly in Africa. In many places, what were previously carbon sinks have turned into sources of carbon emissions.

[ click on images to enlarge ]
Methane

Ominously, high methane peaks have been recorded recently. The image below shows - on the left - that methane reached a peak of 2616 parts per billion (ppb) at 481.5-489 mb on November 28, 2024 pm, with high methane levels recorded over the Arctic and also over Antarctica. The image below shows - on the right - that, on November 28, 2024 pm, high methane levels were present over the oceans at 988.6-1002.4 mb. 



Where does the methane come from?

The image on the right shows methane at pressure levels from 988.6 to 1002.4 mb, which corresponds to near sea level, so no methane does show up on over land with higher elevation, e.g. Greenland, Antarctica, even Australia (lowest continent). 

Methane is light and will rise up in the atmosphere, so more methane will typically accumulate at higher altitudes than at near sea level. Much of the methane that is visible at the higher altitude image (left) is also present at the low altitude image (right) and at relatively high concentrations, peaking at 2415 parts per billion (ppb). 

Furthermore, on the image on the left with the 2616 ppb peak, relatively little extra magenta-colored methane shows up over continental areas where typically high concentrations are present, compared to the image on the right. 

These points indicate that much of the high concentrations of methane could have originated from oceans and from hydrates in sediments that are getting destabilized by high temperature swings. 

[ click on images to enlarge ]

As mentioned above, ocean heat threatens to destabilize sediments that contain hydrates holding huge amounts of methane, resulting in huge amounts of methane abruptly entering the atmosphere.

[ The Buffer has gone, feedback #14 on the Feedbacks page ]
Dangers associated with high temperatures are discussed in this earlier post. A 2018 study (by Strona & Bradshaw) indicates that most life on Earth will disappear with a 5°C rise. Humans, who depend for their survival on many other species, will likely go extinct with a 3°C rise, as illustrated by the image below, from an earlier post.


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

• National Institute of Polar Research Japan
https://ads.nipr.ac.jp

• NOAA - Climate Prediction Center - 14 November 2024
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.html

• University of Bremen - sea ice
also discussed on facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10162009995269679

• NOAA - sea surface temperatures - Contoured Regional Images of Blended 5 km SST Analysis 

• Early-twentieth-century cold bias in ocean surface temperature observations - by Sebastian Sippel et al. 
discussed on facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10161956156144679

• pre-industrial
https://arctic-news.blogspot.com/p/pre-industrial.html

• Climate Reanalyzer
https://climatereanalyzer.org

• Copernicus
https://climate.copernicus.eu

• NOAA - Global Monitoring Laboratory - Carbon Cycle Gases, trends in CO2
https://gml.noaa.gov/ccgg/trends
also discussed on facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10161904718934679 
https://www.facebook.com/SamCarana/posts/10169996053330161

• Sunspots
https://arctic-news.blogspot.com/p/sunspots.html

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

• Jet Stream
https://arctic-news.blogspot.com/p/jet-stream.html

• Pre-industrial
https://arctic-news.blogspot.com/p/pre-industrial.html

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

• NOAA - HEAP IASI - methane
https://www.ospo.noaa.gov/products/atmosphere/soundings/heap/iasi/iasiproducts.html

• Transforming Society
https://arctic-news.blogspot.com/2022/10/transforming-society.html

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

• Climate Emergency Declaration
https://arctic-news.blogspot.com/p/climate-emergency-declaration.html







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