Close Menu
    Trending
    Science

    Did a Terminal Temperature Acceleration Event start in December 2024?

    By No Comments0 Views

    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)

    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

    • NOAA – ENSO: Recent Evolution,
    Current Status and Predictions – 30 December 2024 update

    also discussed on facebook at:

    • 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

    Share.

    Related Posts

    Comments are closed.