Monday, April 6, 2026

A huge rise in temperature in 2026?

Carbon dioxide (CO₂) recorded by NOAA was at a record high of 433.24 parts per million (ppm) on April 5, 2026, at Mauna Loa, Hawaii.

The image below illustrates that the daily average for the de-seasonalized global average CO₂ trend was at a record high of 427.58 ppm on April 11, 2026.

The above image shows daily averaged CO₂ through April 10, 2026, from four observatories: Utqiaġvik, formerly known as Barrow, Alaska (in blue), Mauna Loa, Hawaii (in red), American Samoa (in green), and South Pole, Antarctica (in yellow). The thick black lines represent the average of the smoothed seasonal curves and the smoothed, de-seasonalized curves for each of the records. These lines are a very good estimate of the global average levels of CO₂. 

The annual maximum for CO₂ is typically reached in May, so the daily average CO₂ looks set to reach even higher levels in May 2026. The image below, from an earlier post, shows that the 2024 global CO₂ concentration increased by 3.77 ppm, the highest annual growth on record. 


CO₂ is now higher than it has been for millions of years

The image below, from an earlier post, shows CO₂ over thousands of years through April 1, 2026, when the daily average CO₂ concentration recorded by the Keeling Curve, maintained by Scripps Institution of Oceanography at Mauna Loa Observatory, was 432.81 ppm.


Concentrations of CO₂ haven't been this high for millions of years and they are still increasing rapidly. A recent analysis led by Sarah Shackleton and Julia Marks-Peterson 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 CO₂ levels have likely remained below 300 ppm over this time, as discussed in an earlier post.

This makes the recent daily concentration of 433.24 ppm at Mauna Loa even more threatening. It means that, in addition to the key role of heat-trapping greenhouse gases, there were also important contributions from other components of the climate system such as Earth’s reflectivity, variations in vegetation and/or ice cover and ocean circulation.

According to the IPCC, limiting warming to 2°C would have required global greenhouse gas emissions to have peaked before 2025 at the latest, which hasn't happened. In other words, we're headed for a rise that may exceed 3°C above pre-industrial soon. How fast could such a rise eventuate? The two images and text below are from the earlier post What Does Runaway Warming Look Like?

Forcing caused by the rapid rise in the levels of greenhouse gases is far out of line with current temperatures. A 10°C higher temperature is more in line with these levels, as illustrated by the image below, based on 420,000 years of ice core data from Vostok, Antarctica.


How fast could such a 10°C temperature rise eventuate? The image below gives an idea.


A study led by James Hansen concludes that equilibrium global warming for today’s amount of greenhouse gases is 10°C, which is reduced to 8°C by today’s human-made aerosols, and while James Hansen doesn't expect a 10°C rise soon, he warns that decline of aerosol emissions could increase global warming rapidly, in addition to the acceleration already occurring now.

James Hansen doesn't expect a huge rise to occur soon, as the temperature rise of the atmosphere is slowed by take up of extra energy by oceans, land and ice. 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.

However, extra energy is increasing as greenhouse gas concentrations keep rising, while additionally the capacity of oceans, land and ice to take up extra energy is increasingly compromised. This could cause a huge rise in temperature soon, especially on land in the Northern Hemisphere where there is proportionally more land. The temperature can be expected to rise even faster during heatwaves and especially in large cities that are additionally affected by the Urban Heat Island effect. 

How fast could the temperature rise on land in the Northern Hemisphere exceed 3°C?

The image below shows NASA March 2026 Land+Ocean temperature anomalies vs 1951-1980 in °C.
The above image illustrates that the temperature rise comes with polar amplification, as well as distortion of the Jet Stream enabling cold air to move from high latitudes to lower latitudes and resulting in high temperature anomalies in some areas, with anomalies as high as 10.4°C showing up on the map. 

Feedbacks in the Arctic and the accelerating rise of Arctic temperatures are all too often hidden from public discussion by focusing on long-term global averages, as discussed in earlier posts such as this one. The IPCC also seeks to downplay the dangers by manipulating the rise to come, e.g. by suggesting that forecasts for future temperatures should be based on long periods of historical data that are further manipulated by using linear trends to hide recent acceleration and the potential for further acceleration.

Acceleration of the temperature rise is illustrated by the image below, made with NASA Land-Only anomalies vs. 1880-1890 (not pre-industrial) through March 2026.

The above image indicates that anomalies (vs 1880-1890) have been high since 2021, i.e. the rise in temperature has been at or above 1.5°C for each month since 2021 (black squares connected by the black lines). The Lowess 3-year smoothing trend (red line) indicates that the temperature rise accelerated in 2022 and crossed 2°C in 2022, while the trend further indicates that 3°C may get crossed soon on land (where most people live), in 2029 if this trend continues (linear dashed red extension) or even earlier if the trend's rise accelerates further (as illustrated by the image below with a polynomial trend). 

The image below illustrates that the upcoming El Niño could trigger a rapid and steep rise in temperature on land in the Northern Hemisphere in the course of 2026. 


The image shows land-only data in the Northern Hemisphere through March 2026, with a polynomial trend added that points at 3°C crossed later in 2026. About 0.5°C of the rise can be attributed to El Niño, with further contributions from feedbacks and further forcers. Note that the 1901-2000 base is not pre-industrial, the outlook may be even more dire when using a genuinely pre-industrial base. 

Strong El Niño on the way

The image below, adapted from NOAA, shows ENSO (El Niño-Southern Oscillation) probabilities for the Niño3.4 region (5°N-5°S,120°W-170°W) relative sea surface temperature index, indicating El Niño (red bar) will emerge in the course of 2026.


The bars on the image below, adapted from NOAA, indicate the likely strength of the upcoming El Niño. 


The ECMWF April 2026 forecasts indicate that a very strong El Niño could emerge in the course of 2026, as illustrated by the combination image below.

[ click on images to enlarge ]
According to a NOAA update issued April 6, 2026, La Niña is still present and a transition from La Niña to ENSO-neutral is expected in the next month, so a steep increase in temperature can be expected to occur over the next few months. 

A huge amount of heat has accumulated in oceans, as illustrated by the above image, adapted from Rosenstiel School. Much of this ocean heat is on track to move from the ocean to the atmosphere over the next few months, and much ocean heat will also move along the path of ocean currents to the Arctic Ocean, resulting in sea ice decline.

Arctic sea ice decline

The image below shows that the Arctic sea ice area was 0.74 million km² lower than 1981-2010 on April 11, 2026 (black), the lowest anomaly on record for the time of year and a deviation from 1981-2010 of -2.77σ. Also highlighted are the sea ice area anomaly for 2025 (purple), for 2016 (light purple), when there was a strong El Niño, and for 2012 (blue), when Arctic sea ice area reached a record minimum. 


Loss of Arctic sea ice decline could strongly contribute to the temperature rise, as discussed in an earlier post. The image below, adapted from dmi.dk, shows that Arctic sea ice volume was at a record low for the time of year on April 12, 2026. 


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: 

Climate Emergency Declaration

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 - Recent Daily Average CO2 at Mauna Loa, Hawaii

• NOAA - Daily global CO2

• NOAA - Climate at a Glance Global Time Series

• NOAA - El Niño/Southern Oscillation (ENSO) diagnostic discussion
discussed on facebook at: 

• ECMWF - European Centre for Medium-Range Weather Forecasts - El Niño charts

• NASA - Goddard Institute for Space Studies (GISS) Surface Temperature Analysis
https://data.giss.nasa.gov/gistemp

• Rosenstiel School of Marine, Atmospheric, and Earth Science
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Sunday, April 5, 2026

We missed the target of limiting the temperature rise to 2C

In 2022, the IPCC said that limiting warming to 2°C would require global greenhouse gas emissions to peak before 2025 at the latest, and be reduced by a quarter by 2030.


Let's look into it. Did greenhouse gas emissions peak earlier than 2025? The 2025 Global Carbon Budget in a news release projected 38.1 Gt of fossil carbon dioxide (CO₂) emissions in 2025, a rise of 1.1%, and warned that climate change is reducing the combined land and ocean sinks. It finds that 8% of the rise in atmospheric CO₂ concentration since 1960 is due to climate change weakening the land and ocean sinks.

So, by how much are CO₂ concentrations rising? The image below shows that the 2024 CO₂ concentration increased by 3.77 ppm, the highest annual growth on record.


The image below shows one year of CO₂ daily and weekly means at Mauna Loa, Hawaii, with the daily CO₂ reaching a record high of 432.69 ppm on March 31, 2026. The image also shows a CO₂ concentration of 431.73 ppm for the week beginning on March 29, 2026, an increase of 4.47 ppm compared to 1 year ago. The annual peak in CO₂ is typically reached in May, so the daily average CO₂ looks set to reach an even higher peak in May 2026. How high could the 2026 peak be? 

 
When taking into account CO₂ concentrations recorded at three further locations, the outlook for 2026 is even more dire.

The average growth for the years 2023, 2024 and 2025 was about 3 ppm. The highest daily CO₂ peak in 2025 was 431.25 ppm, so with 3 ppm growth the 2026 CO₂ concentration could reach a daily peak of 434.25 ppm in May, i.e. at the top end of the scale on the image below, or even higher than that, if growth turns out to be more than 3 ppm per year.

The 2025 annual mean at Mauna Loa was 427.35. If this growth of 3 ppm per year persists, CO₂ concentrations could reach an annual mean of 430.35 ppm in 2026. 


High time for the IPCC to warn that we missed the target of limiting the temperature rise to 2°C and that with a 3°C rise in temperature humans are likely to go extinct. 

Climate Emergency Declaration

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

• IPCC - The evidence is clear: the time for action is now. We can halve emissions by 2030. (2022 News Release)
https://www.ipcc.ch/2022/04/04/ipcc-ar6-wgiii-pressrelease

• Global Carbon Budget - Fossil fuel CO2 emissions hit record high in 2025 (November 2025 News Release)
• NOAA - Global Monitoring Laboratory - Carbon Cycle Greenhouse Gases - Mauna Loa, Hawaii
https://gml.noaa.gov/ccgg/trends/mlo.html

• NOAA - Global Monitoring Laboratory - data viewer - Mauna Loa, Hawaii
https://gml.noaa.gov/dv/iadv/graph.php?code=MLO&program=ccgg&type=ts

• Transforming Society 
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Wednesday, April 1, 2026

Carbon dioxide highest in millions of years

Greenhouse gas concentrations

The highest daily average carbon dioxide (CO₂) concentration recorded by the Keeling Curve, maintained by Scripps Institution of Oceanography at Mauna Loa Observatory, was 432.81 parts per million (ppm), recorded on April 1, 2026. The image below shows CO₂ over thousands of years. 


The image below shows that the highest daily average CO₂ concentration recorded by NOAA at Mauna Loa, Hawaii, was 432.69 ppm, recorded on March 31, 2026 (yellow circle on the right). The image also shows hourly (red circles) and daily (yellow circles) averaged CO₂ values from Mauna Loa, Hawaii, over 31 days. The inset on the right shows recent daily averages.


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 March 22, 2026, was 430.93 ppm (red line top right). NOAA's CO₂ average daily concentrations were at a record high of 432.69 ppm, at Mauna Loa, Hawaii, on March 31, 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 432.81 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 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 ]
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.

Methane

Ominously, a peak methane level of 2690 ppb was recorded at 487.2 mb by the NOAA 21 satellite on March 31, 2026 AM, as illustrated by the image below. 


Could the Northern Hemisphere land-only temperature rise exceed 3°C soon?

The upcoming El Niño could trigger a rapid and steep rise in temperature on land in the Northern Hemisphere, as illustrated by the combination image below that uses land-only data in the top panel and Northern Hemisphere data in the bottom panel. 

[ image from earlier post, discussed on facebook here ]
Arctic sea ice

The image below, adapted from dmi.dk, shows that Arctic sea ice volume was at a record low for the time of year on April 5, 2026.


Climate Emergency Declaration

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

• NOAA - Global Monitoring Laboratory - data viewer - Mauna Loa, Hawaii
https://gml.noaa.gov/dv/iadv/graph.php?code=MLO&program=ccgg&type=ts

• NOAA - Office of satellite and product operations - HEAP NUCAPS
https://www.ospo.noaa.gov/products/atmosphere/soundings/heap/nucaps/new/nucaps_products.html

• Broadly stable atmospheric CO2 and CH4 levels over the past 3 million years - by Julia Marks-Peterson et al.
https://www.nature.com/articles/s41586-025-10032-yand

• Global ocean heat content over the past 3 million years - by Sarah Shackleton et al.
https://www.nature.com/articles/s41586-026-10116-3
discussed on Facebook at:
https://www.facebook.com/groups/arcticnews/posts/10164017885199679

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

• Blue Ocean Event
https://arctic-news.blogspot.com/p/blue-ocean-event.html

• The threat of seafloor methane eruptions
https://arctic-news.blogspot.com/2025/11/the-threat-of-seafloor-methane-eruptions.html

• The 2026 El Nino - update March 2026
https://arctic-news.blogspot.com/2026/03/the-2026-el-nino-update-march-2026.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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