Carbon dioxide highest in millions of years - update

Greenhouse gas concentrations

The image below shows the highest daily average carbon dioxide (CO₂) concentration recorded by the Keeling Curve, maintained by Scripps Institution of Oceanography at Mauna Loa Observatory. The CO₂ concentration was 433.49 parts per million (ppm) on May 1, 2026. The background image shows CO₂ over the past two thousand years.

The image below shows the highest daily average CO₂ concentration recorded by NOAA at Mauna Loa, Hawaii. The CO₂ concentration was 433.95 ppm on May 1, 2026 (yellow circle on the right). The image shows hourly (red circles) and daily (yellow circles) averaged CO₂ values from Mauna Loa, Hawaii, over 31 days. 

The image below shows daily (green circles), weekly (red lines) and monthly (blue lines) averages for the last year. The weekly average for the week beginning on April 26, 2026, was 432.44 ppm (red line top right). NOAA's CO₂ average daily concentration was at a record high of 433.95 ppm, at Mauna Loa, Hawaii, on May 1, 2026.

To find CO₂ levels this high back in history, one needs to go back millions of years, as illustrated by the two images below, from an earlier post.

What makes current conditions even more dire is that not only are concentrations of CO₂ extremely high (without match going back millions of years) and rising, but the speed at which CO₂ is currently 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. The image below shows the combined climate forcing by changing CO₂ and solar output for the past 450 million years.

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, click on images to enlarge ]

Given today's extremely high CO₂ levels, why is the temperature in central Europe not 20°C higher today? The answer is that - for now - most of the extra heat trapped by the extremely high (and rising) greenhouse gas levels doesn't stay in the atmosphere, but is absorbed by oceans, by land, and in the process of melting ice. However, the capacity for oceans, land and ice to keep taking up more heat appears to be reducing fast, as described in more detail further below.

Concentrations of carbon dioxide haven't been this high for millions of years, as confirmed by recent analysis led by Sarah Shackleton and Julia Marks-Peterson. Their analysis finds that, while the average temperature of the ocean has decreased by 2 to 2.5°C over the past 3 million years, average atmospheric carbon dioxide levels have likely remained below 300 parts per million over this time. Methane levels have also remained relatively stable. This makes the recent daily concentration of 433.95 ppm at Mauna Loa and the high recent methane levels (see earlier post) even more threatening and it means that, in addition to the key role of heat-trapping greenhouse gases, there were important contributions from other components of the climate system such as Earth’s reflectivity, variations in vegetation and/or ice cover and ocean circulation. There are many feedbacks and further contributors to acceleration of the temperature rise that could add up to a rise of more than 20°C by the end of 2026, as discussed in an earlier post.

Earth energy imbalance

Outgoing longwave radiation is reducing due to rising greenhouse gases, resulting in an increasingly larger amount of extra energy. The image below, from an earlier post, depicts Earth energy imbalance.

According to the IPCC AR6 WG1, 91% of the extra energy is taken up by oceans, 5% by land, 3% by ice melting and 1% remains in the atmosphere. Oceans, land and ice melting thus act as a buffer that did take up the vast majority (99%) of the extra energy, based on IPCC data.  

[ image by Leon Simons, discussed on facebook ]

Not only is the extra energy increasing, as depicted by the above image, but the proportions of where the extra energy is going is additionally changing.

The ocean's capacity to act as an energy buffer is increasingly compromised by stratification, changes to ocean currents, changes in salinity, ocean oxygen depletion, acidification and more, as discussed in earlier posts such as this one. This is a big issue, since oceans take up 91% of the extra heat caused by greenhouse gases, so if there is even a 1% reduction in the heat taken up by oceans, the heat remaining in the atmosphere may double.

Furthermore, the capacity for ice to act as a buffer by consuming energy in the process of melting is increasingly compromised by sea ice decline, by retreat of glaciers, and by darkening of ice due to dust, algae, black carbon and more. Arctic sea ice is facing a Blue Ocean Event with sea ice decline threatening to both dramatically lower albedo and reduce the ability for ocean heat to be consumed in the process of melting. Mountain glaciers are also in decline and permafrost is approaching the point where thawing of permafrost will speed up rapidly, as discussed in earlier posts such as this one.

The capacity for land to take up heat also faces a tipping point: The Land Evaporation Tipping Point can get crossed locally when water is no longer available locally for further evapotranspiration, i.e. from all processes by which water moves from the land surface to the atmosphere via evaporation and transpiration, including transpiration from vegetation, evaporation from the soil surface, from the capillary fringe of the groundwater table, and from water bodies on land. Once this tipping point gets crossed, the land and atmosphere will heat up strongly, due to the extra heat, i.e. heat that was previously consumed by evaporation and thawing, as described at this page.

So, while the extra energy is increasing, as depicted by the above image, the capacity of oceans, land and ice to take up energy is decreasing and an increasingly large amount of extra heat therefore threatens to accumulate in the atmosphere, especially in the Northern Hemisphere over land and in the Arctic, where temperatures are rising faster than anywhere in the world.

Conclusion

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 in this 2022 post and this 2025 post, and as discussed in the Climate Plan group.

Links

• Keeling Curve - by Scripps Institution of Oceanography at UC San Diego
https://keelingcurve.ucsd.edu

• NOAA - Global Monitoring Laboratory - Carbon Cycle Greenhouse Gases - Mauna Loa, Hawaii
https://gml.noaa.gov/ccgg/trends/mlo.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

Arctic and Antarctic sea ice may be gone within ten months

Both Arctic and Antarctic sea ice may be gone within ten months. On April 24, 2026, Arctic sea ice was lowest for the time of year in extent, in area and in volume, as highlighted in an earlier post. The post warns that the upcoming El Niño could cause all Arctic sea ice to disappear in September 2026, resulting in albedo loss, transfer of ocean heat to the atmosphere and additional emissions that could jointly increase global temperatures and subsequently also cause all Antarctic sea to disappear in a matter of months.

The upcoming El Niño threatens to become a monster within months.

The above image, adapted from NOAA, shows a forecast dated May 3, 2026, for the Niño3.4 region (which is indicative for El Niño development), with forecasts partly exceeding 4°C for some forecast members, while part of the forecast for the Coupled Forecast System version 2 (CFS.v2) ensemble mean (black dashed line) exceeds 3°C. The image below shows a forecast for the Niño3 region dated May 3, 2026.

The image below, from an earlier post, shows an April 1, 2026, ECMWF forecast for the Niño3.4 region on the right, with a map of the El Niño regions on the left.

Forecasts of anomalies in sea surface temperature in El Niño regions reaching or exceeding 3°C indicate that the 2026 El Niño will be even stronger than the 2015-16 El Niño, as illustrated by the image below, adapted from NOAA and with a potential 2026-27 El Niño anomaly of 3°C added in red. Note that the image below uses the relative Oceanic Nino Index (RONI), whereas the above forecasts use the Oceanic Nino Indec (ONI) that can show slightly higher anomalies.

[ from earlier post ]

The image below shows the sea surface temperature (SST) in the Nino 3.4 region over the years from the start of the year to June. On April 3, the 2026 SST (red line) was higher than the 2016 SST (thick grey line). From January 9, 2026, through April 30, 2026, the sea surface temperature in the Nino3.4 region has risen by 3.15°C.

Arctic sea ice

The image below, adapted from the Danish Meteorological Institute, shows that the daily Arctic sea ice volume was at a record low for the time of year on May 2, 2026, as it has been for years. 

The April 2026 Arctic sea ice volume was about 18,500 km³ (as illustrated by the image on the right), which is very close to the magenta bar which stands for strong melting (18,000 km³) from the annual maximum volume. 

The image below shows Arctic sea ice volume through April 2026, with the strength of the melting between the annual maximum (blue circle) and the annual minimum (red circle) highlighted by colored bars, magenta for strong melting (18,000 km³) and green for little melting (15,000 km³). 

Last year, only about 15,000 km³ of sea ice melted away from the maximum in 2025 to the minimum in September 2025, and this relatively little melting can be attributed in part to La Niña conditions.

The April 2026 volume was about 18,500 km³, so if strong melting (18,000 km³) will take place over the next few months (dashed magenta line), as can be expected due to El Niño, a Blue Ocean Event will occur and virtually all Arctic sea ice volume will be gone in September 2026. 

Feedbacks, thresholds and tipping points

Sea ice loss comes many feedbacks and there is interaction between feedbacks. As an example, sea ice decline comes with both loss of albedo (Feedback #1) and loss of the latent heat buffer (Feedback #14), each of which will accelerate the temperature rise of the water of the Arctic Ocean, thus contributing to the threat that hydrates contained in sediments at the seafloor of the Arctic Ocean will be destabilized, which in turn threatens to cause eruption of huge amounts of methane (Feedback #16), which will further drive up the temperature in the Arctic and cause stronger melting of terrestrial permafrost.

A further danger lies in changes occurring to wind and ocean current patterns; the temperature rise will cause stronger wind, waves and storms, as well as deformation of the Jet Stream (Feedback #19). In addition, the temperature rise causes loss of reflectivity of clouds (Feedback #25) and more ocean stratification (Feedback #29), exacerbated by more freshwater accumulating at the surface of oceans, due to stronger ice melting, due to heavier runoff from land and rivers and due to changes in wind patterns and ocean currents and circulation. In the North Atlantic, there is the additional danger that formation of a freshwater lid (Feedback #28) will cause huge amounts of ocean heat to be pushed into the Arctic Ocean and enter the atmosphere as sea ice disappears.

Higher temperatures come with feedbacks, as illustrated by the image below, from an earlier post. The image illustrates the mechanism of multiple feedbacks increasing and accelerating the temperature rise (the yellow horizontal bar), and of thresholds and tipping points causing the temperature rise to jump up a step when crossed.

[ the temperature in the atmosphere can keep rising, even in the absence of further emissions ]

Feedback numbers correspond with the list at the feedbacks page. Some of them are discussed below.

Feedback #1: albedo loss (loss of reflectivity) as sea ice melts due to rising temperatures and due to the ice getting covered by soot, dust, algae, meltpools and rainwater pools;

Feedback #14: loss of the latent heat buffer - as sea ice disappears, heat can no longer be consumed by the process of melting, and the heat will instead go into increasing the temperature;

Feedback #19: distortion of the Jet Stream as the temperature difference narrows between the Arctic and the Tropics, in turn causing further feedbacks to kick in stronger, such as hot air moving into the Arctic and cold air moving out, and more extreme weather events bringing heavier rain and more intense heatwaves, droughts and forest fires that cause black carbon to settle on the sea ice;

Feedback #23: open oceans hold more far-infrared energy than sea ice, resulting in warmer oceans, stronger melting of sea ice, with a study showing a 2°C rise in the polar climate after a 25-year run;

Feedback #25: extra water vapor feedback - rising temperatures will result in more water vapor in the atmosphere (7% more water vapor for every 1°C warming), further amplifying the temperature rise, since water vapor is a potent greenhouse gas;

Feedback #28: freshwater lid on the North Atlantic - melting of sea ice and glaciers and thawing of the permafrost results in meltwater accumulating at the surface of the North Atlantic Ocean, where it forms a cold freshwater lid on top of the water; this lid grows further due to more rain falling on top of this lid. This results in less evaporation and transfer of heat from the North Atlantic to the atmosphere, and more ocean heat getting carried by the Gulf Stream underneath the sea surface into the Arctic Ocean;

Feedback #30: The clouds feedback reduces the reflectivity of lower clouds and comes with a tipping point at 1200 CO₂e that, when crossed, causes the temperature rise to increase by an abrupt 8°C. Such a high CO₂e could be reached due to eruption of methane from the seafloor, as discussed in an earlier post and below

Feedback #16: eruptions of seafloor methane - as more heat reaches the seafloor of the Arctic Ocean, sediments and hydrates contained in them destabilize, resulting in methane releases. Vast amounts of methane are held in hydrates at the seafloor of the Arctic Ocean. Miesner et al. (2023) warn that 2822 Gt of organic carbon is stored in subsea Arctic shelf permafrost and Huang et al. (2024) warn that the top two meters of soil globally holds about 2300 Gt of inorganic carbon, which has been left out of environmental models, and 23 Gt of this carbon may be released over the next 30 years. By comparison, the atmosphere contains about 5 Gt of methane. The image below, from an earlier post, illustrates the threat of thinning of Arctic sea ice resulting in increased ocean heat and methane eruptions.

[ The Buffer is gone ]

Ominously, the forecast for August 2026 below shows very high sea surface temperature anomalies for the Arctic Ocean, which spells bad news for Arctic sea ice, which typically reaches its annual minimum in September. 

Antarctic sea ice

Could an Antarctic Blue Ocean Event occur in early 2027? Antarctic sea ice typically reaches its annual minimum in February. As illustrated by the image below, Antarctic sea ice area was only 1.09 million km² on February 22, 2023, very close to the 1 million km² threshold when a Blue Ocean Event could be called.

   [ Saltier water, less sea ice - from earlier post ]

What caused the 2023 Antarctic sea ice decline? Until 2015, rising temperatures resulted in melting of ice and enhanced precipitation that freshened the surface of the Southern Ocean, exacerbated by increasing stratification that prevented mixing. The temperature rise over the years also caused winds to be stronger, at the time causing the sea ice to spread out wider.

The higher the water's salt content, the lower its melting point. Seawater typically has a salinity of about 3.5% (35 grams of salt per liter of water). Sea ice starts melting when the temperature rises to about -2°C (28.4°F). By contrast, freshwater remains frozen as long as the temperature remains below 0°C (32°F).

A recent study led by Theo Spira finds that, in 2015, anomalously strong winds enhanced mixing across the thin Winter Water layer, entraining warm and salty subsurface waters, which broke down upper-ocean stratification. Another recent study led by Earle Wilson find that in 2015, intensified wind-driven upwelling reversed the freshening trends, releasing years of accumulated ocean heat that contributed to unprecedented sea ice loss.

[ image from: 10°C or 18°F warmer by 2021? ]

An earlier post discusses a study led by Alessandro Silvano that finds how, around 2015, surface salinity in the Southern Ocean began rising sharply – just as sea ice extent started to crash.

The post describes that higher temperatures come with feedbacks such as stronger wind and stronger evaporation, resulting in increased water vapor in the atmosphere. Much of the water vapor will return to the surface in the form of precipitation such as rain and snow, but part of this precipitation will fall over Antarctica, with the net result of an increase in salinity of surface of the Southern Ocean. 

The post also points at the danger that heat, previously stored in the deep ocean by sinking circumpolar waters, will instead remain at the surface and cause atmospheric temperatures to rise, as illustrated by the above image.

A recent study warns that Antarctic regions (60°S − 90°S) may warm by around 6°C due to the collapse of the Atlantic meridional overturning circulation (AMOC).

Ominously, the forecast below for January 2027 shows very high sea surface temperatures anomalies around Antarctica, which spells bad news for Antarctic sea ice, which typically reaches its annual minimum in February, as mentioned above. 

Temperature rise

The image below, from an earlier post, uses NASA monthly data through March 2023. Data are first adjusted from NASA's default 1951-1980 base to an earlier 30-year base, i.e. a 1886-1915 base, and then further adjusted by 0.99°C to reflect ocean air temperatures, higher polar anomalies and a pre-industral base.

The image below is a 2025 update, the same adjustments are made to data through April 2025.

The image below is a 2026 update, the same adjustments are made to data through March 2026.

While the above images indicate that we have dodged a few bullets, we keep playing Russian roulette and keep pulling the same clathrate gun's trigger until one day the bullet will be in the chamber. Note also that we've been in a La Niña and a monster El Niño is on the way.

How the 0.99°C adjustment in the above images is calculated is shown in the bright yellow inset of the image below.

[ from April 2024 post, click on images to enlarge ]

The images show that, when adjusting the data and using a genuinely pre-industrial base, the temperature rise may have already crossed both the 1.5°C and the 2°C thresholds that politicians at the 2015 Paris Agreement pledged shouldn't and wouldn't be crossed.

Human extinction

In 2022, the IPCC said that limiting warming to 2°C would require global greenhouse gas emissions to peak before 2025 at the latest. As discussed in an earlier post, it looks like we have missed the target of limiting the temperature rise to 2°C, while humans are likely to go extinct with a 3°C rise in temperature, yet the IPCC refuses to warn people about the dire situation.

The screenshot below describes the existential danger for humans.

The screenshot below adds:

[ from the 2019 post When Will We Die? ]

Conclusion

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 in this 2022 post and this 2025 post, and as discussed in the Climate Plan group.

Links

• NOAA - Seasonal climate forecast from CFSv2
https://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2_body.html

• NOAA - ENSO: Recent Evolution, Current Status and Predictions - Update issued April 27, 2026
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

• Climate Reanalyzer
https://climatereanalyzer.org

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

• Tropicaltidbits.com
https://www.tropicaltidbits.com

• 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

Double Blue Ocean Event 2026-2027?

Arctic sea ice

A Blue Ocean Event could be declared when Arctic sea ice reaches or crosses a threshold of 1 million km² in extent. On April 24, 2026, Arctic sea ice extent was 13.21 million km², the lowest extent on record for the time of year and a deviation from 1981-2010 of -2.71σ, as illustrated by the image below. 

The situation is very dangerous, because this low sea ice extent comes at a time when El Niño is developing and may become a very strong El Niño. Loss of sea ice extent is only one way to measure decline. 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 and the capacity of sea ice to act as a buffer that consumes incoming ocean heat. Accordingly, the critical threshold for a Blue Ocean Event to occur can be said to be 1 million km² in area.

The image below shows Arctic sea ice area over the years, with 2012 highlighted in blue and 2026 highlighted in black. On September 12, 2012, Arctic sea ice area was 2.24 million km². On April 24, 2012, Arctic sea ice area was 12.82 million km². On April 24, 2026, Arctic sea ice area was 11.50 million km², a record low for the time of year and 1.32 million km² lower than it was on April 24, 2012. A Blue Ocean Event may occur in September 2026, if Arctic sea ice area would then be at least 1.24 million km² lower than it was in 2012. 

Yet another way to measure Arctic sea ice decline is volume, and yes, Arctic sea ice volume was also the lowest on record for the time of year on April 24, 2026, as it has been for a long time. The image below, adapted from the Danish Meteorological Institute, shows Arctic sea ice volume at a record low for the time of year on April 29, 2026. 

At the end of April 2025, Arctic sea ice maximum volume was about 19,000 km³, as highlighted by the image on the right, and the 2026 maximum appears to be even lower, about 18,000 km³.

That 18,000 km³ is an important number. The image below shows Arctic sea ice volume through April 18, 2026, with the strength of the melting between April (annual maximum, blue) and September (annual minimum, red) indicated by bars colored magenta (strong melting, 18,000 km³) and green (little melting, 15,000 km³).

A record low maximum volume was reached in April 2025. Relatively little melting took place from April 2025 to September 2025, yet a record low minimum volume was reached in September 2025. The April 2026 maximum looks set to be even lower, i.e. about 18,000 km³.

In the above image, the difference between strong melting (magenta) and little melting (green) is 3000 km³. With strong melting taking place from April 2026, this may well cause a Blue Ocean Event to occur, with virtually all Arctic sea disappearing in September 2026. 

The above combination image, adapted from images by the University of Bremen, illustrates two further ways to measure sea ice decline. The panel on the left shows Arctic sea ice thickness on April 24, 2026. The panel on the right shows Arctic sea ice concentration on April 24, 2026. 

Methane threat

The image below, from an earlier post, illustrates the threat of thinning of Arctic sea ice resulting in increased ocean heat and methane eruptions. Arctic sea ice decline could strongly contribute to the temperature rise, as illustrated by the image below and also discussed in this earlier post.

[ The Buffer is gone ]

The image below, adapted from a recent study, depicts the origin of methane releases, i.e. methane from hydrates and methane in the form of free gas (natural gas).

The image below, adapted from the same study, shows that the majority of samples analyzed of Laptev Sea methane releases contains subsea permafrost-associated methane (SPAM) from the upper subsea permafrost layer, as opposed to methane from thermogenic and microbial gas (FOPRIM and FOTSEM) from deeper sedimentary basins.

Temperature

The world (60°S–60°N, 0–360°E) sea surface temperature (SST) was at a record high for the time of year on April 19, 2026, as illustrated by the image below. 

Recently, the 2026 SST was just short of the record high SST of 21.17°C reached in 2024. The 2026 SST has risen strongly and keeps rising, even as the average anomaly for earlier years is coming down due to the change of seasons that is causing SST to come down in the Southern Hemisphere where most of the world oceans are located. 

The image below, adapted from NOAA, shows a forecast for August 2026 of sea surface temperature anomalies. 

In the Southern Hemisphere, the surface air temperature remains at a record high for the time of year, as illustrated by the image below that shows SH temperatures through April 14, 2026. 

What makes the situation particularly dangerous is that an El Niño is on the way that may be very strong. With high SST in the Southern Ocean in December 2026, Antarctic sea ice will undergo very strong melting, threatening an Antarctic Blue Ocean Event to occur early 2027.

Antarctic sea ice

Could an Antarctic Blue Ocean Event occur in early 2027? As illustrated by the image below, Antarctic sea ice area was only 1.09 million km² on February 22, 2023, very close to the 1 million km² threshold when a Blue Ocean Event could be called.  

   [ Saltier water, less sea ice - from earlier post ]

What caused the 2023 Antarctic sea ice decline? Until 2015, rising temperatures resulted in melting of ice and enhanced precipitation that freshened the surface of the Southern Ocean, exacerbated by increasing stratification that prevented mixing. The temperature rise over the years also caused winds to be stronger, at the time causing the sea ice to spread out wider.

The higher the water's salt content, the lower its melting point. Seawater typically has a salinity of about 3.5% (35 grams of salt per liter of water). Sea ice starts melting when the temperature rises to about -2°C (28.4°F). By contrast, freshwater remains frozen as long as the temperature remains below 0°C (32°F).

A recent study led by Theo Spira finds that, in 2015, anomalously strong winds enhanced mixing across the thin Winter Water layer, entraining warm and salty subsurface waters, which broke down upper-ocean stratification. Another recent study led by Earle Wilson find that in 2015, intensified wind-driven upwelling reversed the freshening trends, releasing years of accumulated ocean heat that contributed to unprecedented sea ice loss.

An earlier post discusses a study led by Alessandro Silvano that finds how, around 2015, surface salinity in the Southern Ocean began rising sharply – just as sea ice extent started to crash. The post describes that higher temperatures come with feedbacks such as stronger wind and stronger evaporation, resulting in increased water vapor in the atmosphere. Much of the water vapor will return to the surface in the form of precipitation such as rain and snow, but part of this precipitation will fall over Antarctica, with the net result of an increase in salinity of surface of the Southern Ocean. The post also points at the danger that heat, previously stored in the deep ocean by sinking circumpolar waters, will instead remain at the surface and cause atmospheric temperatures to rise.

A recent study warns that Antarctic regions (60°S − 90°S) may warm by around 6°C due to the collapse of the Atlantic meridional overturning circulation (AMOC). 

El Niño

An earlier post describes how the upcoming El Niño could cause dramatic loss of Arctic sea ice and further emissions that could jointly increase global temperatures and contribute to an Antarctic sea ice decline even stronger than in 2023. 

The image below shows an April 1, 2026, ECMWF forecast for the Niño3.4 region on the right, with a map of the El Niño regions on the left.  

The upcoming El Niño is likely to peak at the end of 2026, as illustrated by the image below. El Niño is named after the Spanish phrase "El Niño de Navidad," meaning "the Christ Child" or "the little boy," as South American fishermen in the 1800s noticed that the unusually warm ocean waters—which reduced their fish catch—tended to peak around Christmas time.

The above image, adapted from NOAA, shows a forecast issued April 28, 2026, for the Niño3.4 region (which is indicative for El Niño development), with forecasts going partly off the scale for some forecast members, while part of the forecast for the Coupled Forecast System version 2 (CFS.v2) ensemble mean (black dashed line) exceeds 3°C. The image below shows forecasts for the Niño3 region issued April 29, 2026.

Forecasts of anomalies in sea surface temperature anomalies in El Niño regions reaching or exceeding 3°C indicate that the 2026 El Niño will be even stronger than the 2015-16 El Niño, as illustrated by the image below, adapted from NOAA and with a potential 2026-27 El Niño anomaly of 3°C added in red. Note that the image below uses the relative Oceanic Nino Index (RONI), whereas the above forecasts use the Oceanic Nino Indec (ONI) that can show slightly higher anomalies. 

The image below shows the sea surface temperature (SST) in the Nino3.4 region over the years from the start of the year until late June. On April 29, the 2026 SST (red line) was higher than the 2016 SST (thick grey line). From January 9, 2026, through April 29, 2026, the sea surface temperature in the Nino3.4 region has risen by 3.03°C. 

The combination image below shows sea surface temperature anomalies in the Niño 1+2 region (located closer to South America) with a rise of more than 3°C (from less than -1.5°C to above +1.5°C) occurring over the past four months through April 23, 2026.

For more on forecasts of the strengthening of the upcoming El Niño, see this earlier post.

Conclusion

In conclusion, an Arctic Blue Ocean Event could occur in September 2026, followed by an Antarctic Blue Ocean Event in early 2027. 

Climate Emergency Declaration

The feedbacks map below is adapted from an image by Peter Carter, Climate Emergency Institute. 

[ click on images to enlarge ]

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 in this 2022 post and this 2025 post, and as discussed in the Climate Plan group.

Links

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

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

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

• Triple-isotopic analyses pinpoint microbial methane release from subsea permafrost in the inner Laptev Sea - by Marenka Brussee et al.

https://www.nature.com/articles/s43247-026-03222-7
discussed on facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10164176083474679

• Climate Reanalyzer
https://climatereanalyzer.org

• Tropicaltidbits.com
https://www.tropicaltidbits.com

• Wind-triggered Antarctic sea-ice decline preconditioned by thinning Winter - by Theo Spira et al. Water https://www.nature.com/articles/s41558-026-02601-4

discussed on facebook at:
https://www.facebook.com/groups/arcticnews/posts/10164023607639679

• Recent extremes in Antarctic sea ice extent modulated by ocean heat ventilation - by Earle Wilson et al. https://www.pnas.org/doi/10.1073/pnas.2530832123
discussed on facebook at:
https://www.facebook.com/groups/arcticnews/posts/10164149040674679

• Collapse of the Atlantic meridional overturning circulation would lead to substantial oceanic carbon release and additional global warming - by Da Nian et al. (2026)

https://www.nature.com/articles/s43247-026-03427-w
discussed on Facebook at: 

https://www.facebook.com/groups/arcticnews/posts/10164168209144679

• ECMWF El Nino forecasts
https://charts.ecmwf.int/products/seasonal_system5_nino_plumes?base_time=202604010000&nino_area=NINO3-4

• NOAA - Seasonal climate forecast from CFSv2

https://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2_body.html

• NOAA - ENSO: Recent Evolution, Current Status and Predictions - Update issued April 27, 2026
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

• Copernicus - Nino 3.4 Sea Surface Temperature time series from Reanalysis
https://data.marine.copernicus.eu/product/GLOBAL_OMI_CLIMVAR_enso_sst_area_averaged_anomalies/description

• Peter Carter - Climate Emergency Institute
https://www.climateemergencyinstitute.com

• 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