Arctic News: Huge temperature rise in 2026?

Monday, December 29, 2025

Huge temperature rise in 2026?

[ image from 1991 poster ]

The image on the right was included in a poster featuring at the AGU Fall Meeting in 1991. The image warned about an escalating temperature rise in the Arctic, pointing at a 10°C rise in the Arctic by 2036. The poster warns that this rise threatens to trigger seafloor methane releases resulting in runaway global warming.

Over time, further contributors to the temperature rise have been highlighted with the warning that they could jointly trigger a total potential global temperature rise of 10°C as early as 2026.

A huge temperature rise threatens to unfold and it could do so as early as next year (2026), as illustrated by the image on the right. Altogether, the temperature rise from pre-industrial could be more than 18.44°C by the end of 2026.

[ see the Extinction page ]

The barchart on the right conceptually dates back to 2016, when a strong El Niño came with a strong temperature rise. When expressed by means of a polynomial trend that was extended by a decade, the trend pointed at a 10°C rise by 2026.

The barchart has basically remained the same over the past ten years, be it that the historic temperature rise from pre-industrial has turned out to be larger (pink) and that the cloud feedback could add a further 8°C to the rise (grey). Also, for clarity, aerosols have been split up into on the one hand sulfates (green) and on the other hand carbon monoxide, black & brown carbon and non-methane volatile organic carbon (brown).

Importantly, posts have over time pointed out that humans are likely to go extinct with a rise of 3°C and most life on Earth will disappear with a 5°C rise, as illustrated by the image below, from an analysis discussed in an earlier post.

With the year 2026 approaching fast, it is time to have another look at how fast and by how much temperatures could rise. The danger of a strong El Niño emerging in 2026 is highlighted below and this could come at a time when emissions are high, Earth's albedo is low and both land and ocean sinks are losing their capacity to take up carbon dioxide and heat.

[ from earlier post ]

The image below shows how, over the course of the year, temperature anomalies in 2023, 2024 and 2025 each have at times reached the highest daily records, even though 2025 wasn't an El Niño year. The image shows temperature anomalies from 1940 through to December 29, 2025, compared to 1991-2020, which isn't pre-industrial.

[ click on images to enlarge ]

The image below, from an earlier post, shows NASA Land Only monthly temperature anomalies (black squares) with respect to 1880-1890 (not pre-industrial) through November 2025 and shows the 1.5°C threshold crossed for all months since 2022. The Lowess 3-year smoothing trend (red line) indicates that the 2°C threshold was crossed in 2022 and that 3°C may get crossed in 2028 if this trend continues (dashed extension). The picture could look even worse when a genuinely pre-industrial base was used and a polynomial trend was applied and extended.

[ Potential Land-only rise, from earlier post ]

As said, the image at the top shows very high temperatures in 2025, even though 2025 wasn't an El Niño year. In other words, current temperatures are suppressed. Moving from the bottom of a La Niña to the peak of a strong El Niño can in itself make a difference of more than 0.5°C. This is illustrated by the image below, from an earlier post, that shows a temperature rise of more than 0.5°C from November 2022 to March 2023, when the last El Niño had not yet even started.

[ Temperature rise due to El Niño from earlier post ]

How deep into La Niña conditions are we at the moment? Sea surface temperatures in the Niño-3.4 region of the equatorial Pacific Ocean (5°N-5°S, 120°W-170°W) are indicative for El Niño/La Niña conditions. The image below shows the location of that region (square on the globe, inset) and graphs with the sea surface temperatures in the Niño-3.4 region for each of the days of the years from 1981 through December 27, 2025.

The image below shows a graph with temperature anomalies in the Niño-3.4 region from 1950 through November 2025, when the anomaly was -0.68°C.

[ click on images to enlarge ]

The image on the right shows a NOAA update of Niño-3.4 region temperature anomalies and forecasts.

NOAA considers a La Niña event to occur when a one-month negative sea surface temperature anomaly of -0.5° C or less is observed in the Niño-3.4 region of the equatorial Pacific Ocean (5°N-5°S, 120°W-170°W) and is forecasted to persist for three consecutive months, while an atmospheric response typically associated with La Niña must also be observed over the equatorial Pacific Ocean.

[ from an earlier post ]

The image on the right, adapted from NOAA, shows ENSO (El Niño-Southern Oscillation) probabilities, with El Niño (red bar) emerging in the course of 2026.

The graph below, adapted from tropicaltidbits, uses CDAS (Climate Data Assimilation System) data showing an anomaly of -1.272°C on Dec 28, 2025. The graph gives another idea as to how deep we have descended into La Niña conditions.

The CDAS analysis below shows very low sea surface temperature anomalies (in blue) in the Niño3.4 region in the Central Pacific on December 28, 2025.

The image below, adapted from ECMWF, shows the ENSO anomalies and forecasts for developments through November 2026 in Niño3.4 (left panel) and in Niño1+2 (right panel), indicating that the next El Niño will emerge and strengthen in the course of 2026.

[ from earlier post ]

How large could the temperatures rise be?

Sea ice is low at both poles. The image below shows Antarctic sea ice on December 31, 2025. Massive loss of albedo amplifies the decline of Antarctic sea ice and the decline of the snow and ice cover over Antarctica, resulting in elevated global temperatures that could persist through September 2026, when Arctic sea ice typically reaches its minimum extent.

As discussed above, moving from the depth of a La Niña to the peak of a strong El Niño in itself could make a difference in the global temperature of more than 0.5°C. Add up feedbacks and the combined impact could trigger a huge temperature rise, since the rise is already accelerating, due to the self-amplifying nature of feedbacks such as albedo loss and more water vapor in the atmosphere, and due to further feedbacks that come with the temperature rise itself such as ocean stratification.

[ image from earlier post ]

[ from earlier post ]

Oceans are still absorbing an estimated 91% of the excess heat energy trapped in the Earth's climate system due to human-caused global warming. If just a small part of that heat instead remains in the atmosphere, this could constitute a huge rise in air temperature. Heat already stored in the deeper layers of the ocean could also rise up and commit Earth to further additional surface warming in the future.

The image on the right illustrates how the temperature rise can cause oceans to take up less heat, resulting in more heat remaining in the atmosphere.

[ from earlier post ]

The above image shows very high temperature anomalies forecast around Antarctica and over the Arctic Ocean for September 2026, at a time when Arctic sea ice volume is expected to be very low. Arctic sea ice volume is at a record low for the time of year, it has been at a record daily low for well over a year. The image below shows Arctic sea ice volume through December 30, 2025.

There is a huge danger that seafloor methane and methane from thawing terrestrial permafrost will add strongly and abruptly to the temperature rise, as discussed in many earlier posts such as this one and as illustrated by the screenshot below.

[ screenshot from earlier post ]

The methane danger is further illustrated by the image below that shows hourly average in situ methane measurements well above 2400 ppb (parts per billion). The image is adapted from an image issued by NOAA December 31, 2025. The image shows methane recorded over the past few years at the Barrow Atmospheric Baseline Observatory (BRW), a NOAA facility located near Utqiaġvik (formerly Barrow), Alaska, at 71.32 degrees North latitude.

Climate Emergency Declaration

UN secretary-general António Guterres recently spoke about the need for “a credible global response plan to get us on track” regarding the international goal of limiting the global temperature rise. “The science demands action, the law commands it,” Guterres said, in reference to a recent international court of justice ruling. “The economics compel it and people are calling for it.”

What could be added is that the situation is dire and unacceptably dangerous, and the precautionary principle necessitates rapid, comprehensive and effective action to reduce the damage and to improve the outlook, where needed in combination with a Climate Emergency Declaration, as described in posts such as this 2022 post and this one and as discussed in the Climate Plan group.