Showing posts with label acceleration. Show all posts
Showing posts with label acceleration. Show all posts

Saturday, October 17, 2026

Global Warming from 1900

At the adoption of the Paris Agreement in 2015, nations pledged to hold the global average temperature rise to well below 2°C above pre-industrial levels and to pursue efforts to limit the temperature rise to 1.5°C above pre-industrial levels.

The image below, with the title Global Warming from 1900, featured in a 2016 post, now ten years ago.


In the above image, data are adjusted, showing the 1.5°C threshold crossed for two months in 2016. The added trend ominously shows the 1.5°C threshold getting crossed more permanently in 2022, while pointing at 2°C getting crossed in 2030.

What is pre-industrial?

The above 2016 image uses adjusted NASA data and a polynomial trend to illustrate the accelerating temperature rise from 1900. An adjustment of +0.28°C caters for the rise from 1900 to 1951-1980, since 1951-1980 is NASA's default base, which isn't a pre-industrial base. For more on such adjustment, also see this 2015 post. Of course, the year 1900 isn't pre-industrial either. For an analysis of the temperature rise going further back in time, have a look at the pre-industrial page and the image below. 

[ from earlier post ]
The issue is not merely a matter of which date is used as pre-industrial base, but also a matter of the elements that are included in the temperature to rise and what their respective size could be. An example is ocean temperature, the NOAA dataset uses sea surface temperatures, i.e. the temperature of the water, whereas the ERA5 dataset uses the temperature of the air above the water. Another issue is whether to measure the Arctic temperature by looking at the air over the ice, the ice itself or the water underneath the ice. Also important is that some areas are now open water, while there was previously sea ice. 

Elements of the temperature rise

The image below looks at elements to be looked at when calculating people's contribution to the temperature rise to date and the temperature rise to come. 

The IPCC regards the observed temperature as a temperature rise (or anomaly) from the period 1850-1900. The observed temperature rise is partly masked by aerosols (M). Aerosols could fall out of the air quickly in case of industrial collapse, removing the part of the temperature rise that is now masked, so the rise from 1850-1900 could quickly become only (O), instead of (O+M). 

The masking effect by aerosols results from industrial emissions, particularly sulfur dioxide (SO₂) emissions from fossil fuel burning that convert into sulfates through atmospheric oxidation. Airborne sulfate particles are white, reflecting incoming solar radiation back into space. 

Another type of aerosols is black carbon, which has a warming effect. Before the Industrial Revolution, people burned wood and crop residue for household heating, cooking and metallurgy, resulting in emissions of black carbon. A 2013 study calculates that black carbon has a warming effect of about 1.1 W/m² of which 0.17 W/m² can be attributed to pre-industral emissions of black carbon. In case of industrial collapse, part of the future rise (F) could be caused by more warming due to releases of other aerosols that have a net warming impact, such as black and brown carbon, which can increase dramatically as more wood burning and forest fires take place as industrial activity collapses and as more waste gets burned.

As said, the IPCC calculates the anomaly from the period 1850-1900, which ignores the rise before that period (P). The IPCC also ignores the rise that took place to negate the natural decline in temperature (H). When also taking into account that the temperature would have declined naturally, i.e. in line with Milankovitch cycles and in the absence of emissions by people (E3), the rise caused by people to negate this decline could also be included (H), adding up to an even higher historic temperature rise (O+M+P+H), while there could be an additional rise to come soon that could also be huge (F).

[ from earlier post ]

Additionally, the full impact of all past emissions may not be fully felt yet, e.g. the full effect of carbon dioxide emissions reaches its peak only a decade after emission (E4). Furthermore, humans are likely to continue to cause emissions in the near future (E5). Finally, additional releases of greenhouse gases are likely to come from what was once called permafrost and from sinks turning into sources, resulting in an additional rise that's already baked into the cake (E6). Therefore, the historic rise plus the rise to come soon (O+M+P+H+F) may approach 5°C.

Feedbacks and deforestation

The diagram below further illustrates the importance of feedbacks and deforestation. Removal of trees has caused deforestation and soil carbon loss since prehistoric times, in turn causing emissions including carbon dioxide, methane and black carbon, while also reducing cooling aerosols released by trees and while also reducing the heat buffer of evaporation and the heat buffer of snow and ice that previously cooled the atmosphere. Since prehistoric times, burning wood and deforestation has caused emissions of black carbon and dust that blackened the snow and ice cover, thus further speeding up its decline.

[ from earlier post ]
Feedbacks can dramatically increase the temperature rise, as they can be self-amplifying or can amplify each other.

Which trend works best?

Next to the question of how best to calculate how much people have caused the temperature to rise, there is a question of which trend works best to capture both the temperature rise until now and the potential rise to come. 

The image below, from a recent analysis led by Qinjian Jin, uses linear trends showing the temperature rising during 2011–2025 at a rate of 0.40°C per decade (purple), twice as much as the 0.20°C per decade during 1971–2025 (yellow). Extrapolating the accelerated (purple) rate projects a crossing of the 1.5°C threshold by 2028. The analysis shows that the temperature rise has doubled, but the analysis stops short of using curved lines or polynomial trends and instead sticks to linear trends. 


The analysis is also discussed by Paul Beckwith in the video below. 


By comparison, the IPCC in AR6 gives values as depicted in the image below. 


The image below is adapted from a 2023 analysis by James Hansen et al.


James Hansen et al. also conclude that the temperature rise is accelerating, but they also stop short of using curved lines or polynomial trends and instead stick to linear trends.

One problem with linear trends is that they calculate the average temperature during a period, thus showing the average temperature over past years, while masking the current temperature and a potentially steep rise in future. In other words, linear trends can obscure both recent and future acceleration. By contrast, curved lines and polynomial trends are better equipped to illustrate potential acceleration, while they can also smooth out seasonal and temporary changes. 

Huge temperature rise

[ from the Extinction page ]
The image on the right is a later version of an image dating back to 2016 that warns about the importance of taking into account a potentially huge rise soon. Disappearance of Antarctic sea ice would be a horrendous climate disaster, increasing the likelihood of a subsequent Arctic Blue Ocean Event. The danger is that multiple feedbacks associated with sea ice loss, such as albedo loss, will strongly accelerate the temperature rise, as warned about at Double Blue Ocean Event and the Antarctica page.

Eruptions of methane from the seafloor could, on their own, cause the 1200 ppm CO₂e cloud feedback tipping point to be crossed, which in turn can cause global temperatures to rise by 8°C, as discussed in this earlier post.

Temperatures look set to rise further due to the falling away of sulfate aerosols, while there could be a additional temperature rises due to releases of other aerosols that have a net warming impact, such as black and brown carbon, which can increase dramatically due to more wood burning and forest fires taking place as industrial activity collapses.

Pursuing efforts?

Most nations have meanwhile ratified the Paris Agreement, which means that politicians are legally obliged to adhere to the Paris Agreement thresholds. However, after more than a decade of pursuing efforts, little or no progress appears to have been made.

The temperature rise is clearly accelerating and denying such acceleration is yet another sick trick in the books of the politicians who control the IPCC, next to using an inappropriate base (instead of pre-industrial), ignoring parts of the current and future temperature rise, and inappropriately using linear trends, even when polynomials obviously work better.

Conclusion

A decade ago, the post concluded as follows: the situation is dire and calls for comprehensive and effective action as described in the Climate Plan. This applies even more today. The situation is dire and unacceptably dangerous, and the precautionary principle necessitates the danger to be acknowledged, while facilitating 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. For an update of the Climate Plan, see the Climate Plan by Sam Carana. 

Links

• Pursuing efforts? (2016)
the image at the top is discussed on facebook at

• NASA GISS Surface Temperature Analysis (GISTEMP)

• A recent doubling of global warming rate signals a 1.5 °C breach by 2028 - by Qinjian Jin et al. (2026) 

• Global Warming Rate Has Recently Doubled Meaning We Pass 1.5C By 2028 and 2.0C by as Early as 2038 - video by Paul Beckwith
discussed on facebook at

• Global warming in the pipeline - by James Hansen et al. (2023)

• Pre-industrial

• Paris Agreement (2015)


• When Will We Die? (2019)

• Extinction (2016)

• Transforming Society (2022)

Posted by at
Labels: , , , , , , ,

Thursday, March 26, 2026

Signals flashing red indicating further acceleration toward climate collapse

Greenhouse gas concentrations

The image below shows hourly (red circles) and daily (yellow circles) averaged carbon dioxide (CO₂) values from Mauna Loa, Hawaii, over 31 days. The highest daily average CO₂ concentration on record, 431.95 ppm, was recorded at Mauna Loa, Hawaii, on March 28, 2026 (third yellow circle from the right). In bold on the image are recent daily averages, since March 24, 2026.


CO₂ average daily concentrations were at a record high of 431.95 parts per million (ppm), at Mauna Loa, Hawaii, on March 28, 2026. 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).


The image below shows daily average CO₂ concentration at Mauna Loa, Hawaii since 2020. The highest daily average CO₂ concentration on record, 431.95 ppm, was recorded at Mauna Loa, Hawaii, on March 28, 2026.


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 431.95 ppm at Mauna Loa and the high recent methane levels (see image below) 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.

[ click on images to enlarge ]

The above combination image shows methane levels as high as 2240 parts per billion (ppb) close to sea level (left panel, 1000 mb) and as high as 2541 ppb at a slightly higher altitude (right panel, 840 mb) recorded by the NOAA 21 satellite on March 11, 2026 AM. The combination image below shows methane levels as high as 231 ppb at 1000 mb (left panel) and as high as 2576 ppb at 399.1 mb (right panel) recorded by the NOAA 20 satellite on March 11, 2026 PM.


Together, these combination images support the suggestion that a burst of methane did enter the atmosphere at a location over the ocean, resulting in very high methane levels in the morning slightly above sea level and even higher methane levels higher up in the atmosphere later that day. 

Sea surface temperature

The image below shows world (60°S–60°N, 0–360°E) sea surface temperatures from NOAA OISST V2.1. The sea surface temperature was 21.15°C on March 27, 2026, a record high temperature for the time of year and a +0.75°C anomaly compared to 1982-2010. The sea surface temperature has risen by 0.46°C since the start of 2026.


Furthermore, changes in salinity and ocean currents, together with ocean stratification, ocean oxygen depletion and sea ice loss can result in oceans changing from heat sinks into heat sources, resulting in more heat remaining in the air and getting transferred to the air, as discussed in earlier post such as this one and as discussed in this analysis, also discussed here.

Earth Albedo

The image below, adapted from an image by Eliot Jacobson, shows now much the Earth Albedo (reflectivity) has fallen from February 23 through January 2026.


Arctic sea ice

One of the contributors to albedo loss is Arctic sea ice loss. The image below, adapted from NSIDC, shows that on March 25, 2026, the Arctic sea ice extent was 14.011 million km², the lowest extent on record for the time of year.

The image below, adapted from ads.nipr.ac.jp, shows that Arctic sea ice extent was 13.37 million km² on March 27, 2026, the lowest sea ice extent on record for the time of year. 

The situation is very dangerous, since we're moving out of a La Niña (which is suppressing the temperature) into an El Niño (which will be elevating the temperature). 

The danger is that a Blue Ocean Event will occur in 2026 if Arctic sea ice continues to be low and if melting from April 2026 onward will be strong. A Blue Ocean Event can be said to occur when virtually no sea ice remains to keep consuming ocean heat that is entering the Arctic Ocean mainly from the Atlantic Ocean. Virtually no sea ice could be 1 million km² or less in sea ice extent, but it could also be measured in area, as illustrated by the image below.

The image below shows that the Arctic sea ice area was the lowest on record on March 25, 2026. Arctic sea ice area was 13.43 million km² on March 25, 2012, and area was 12.31 million km² on March 25, 2026, i.e. a difference of 1.12 million km² and the same difference as there was on March 20, 2026. Arctic sea ice area was 2.24 million km² on September 12, 2012, so with this difference persisting, Arctic sea ice area would be 1.12 million km² in September 2026, or very close to a Blue Ocean Event.


The danger that a Blue Ocean Event will occur in September 2026 is further illustrated by the image below. The image, from an earlier post, which shows Arctic sea ice volume in the past 25 years. Markers show April (blue) and September (red) volume, corresponding with the year's maximum and minimum. In 2025, Arctic sea ice reached a record low maximum volume, as well as a record low minimum volume.


As illustrated by the above image, adapted from dmi.dk, Arctic sea ice volume was very low in April 2025, so while relatively little melting took place from April 2025 to September 2025, a record low Arctic sea ice volume was still reached in September 2025. The above image shows Arctic sea ice volume through mid February 2026, with an analysis of the strength of the melting between April (annual maximum) and September (annual minimum) by means of the bars colored magenta (strong melting) and green (little melting).

If the downward trend in annual maxima (blue circles) continues, Arctic sea ice looks set to reach an even lower maximum volume in April 2026. The difference between strong melting (magenta) and little melting (green) is 3000 km³, so if strong melting will take place from April 2026, this may well cause a Blue Ocean Event to occur later in 2026. A Blue Ocean Event could also be said to occur when only 1000 km³ or less Arctic sea ice volume remains. The image below, adapted from dmi.dk, shows that Arctic sea ice volume was at a record low for the time of year on March 31, 2026. 


Could the N.H land-only temperature rise by more than 3°C in 2027?

The image below, adapted from Copernicus, shows that the global surface air temperature was 14.31°C on March 26, 2026, the highest temperature on record for the time of year. 


Could the temperature rise by more than 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. While the image shows NASA data from 2011 until 2028 (top panel, land-only) and data from 2011 until 2029 (bottom panel, N.H), the trends are calculated using annual data from 2010 through 2025. The quartic trends point at the temperature crossing 3°C in the Northern Hemisphere in early 2028 (bottom), and on land-only in early 2027.  


There are compound impacts such as that the temperature will rise faster on land in the Northern Hemisphere, and even faster during heatwaves in large cities where they are affected by the Urban Heat Island effect. Moreover, the 1880-1920 base is not pre-industrial, the outlook may be even more dire when using a genuinely pre-industrial base. 

Note also that the above are annual average temperature anomalies, i.e. the average for higher and lower anomalies during the year. A recent study shows that extreme global climate outcomes may occur even under moderate 2°C warming for several sectors. For droughts in global key breadbasket regions, precipitation extremes over highly populated areas and fire weather extremes across forests, global climatic impact-drivers at 2°C of global warming may turn out to be much more extreme than model-averaged projections at 3°C or 4°C warming. Indeed, the peaks are more critical than the averages. 

Recent research finds that, while fully frozen permafrost can be considered both to function as a seal preventing subsurface gases being released, and to prevent the creation of new CO₂ and CH₄, gas permeability increases by about 25–100 times during thawing, with most permeability change occurring in the −5°C to −1°C range, indicating that the protective gas seal previously provided by permafrost will be lost as permafrost thaws.

The danger is that the temperature will not merely "overshoot" the 3°C threshold, but that the temperature will continue to rise, especially on land in the Northern Hemisphere, and accelerate over the Arctic. Given the severity, ubiquity and imminence of the danger, one would think that highlighting the danger will prompt people into taking effective climate action, but the outlook is that the temperature will continue to rise for at least a few years, hence the choice of the trend and the canvas, which in the above image is limited to 3°C and until 2028, respectively 2029 (as also discussed on facebook here).

Polynomial trends such as the one in the above image can highlight warnings about dangers that are discussed in this post and in earlier posts, in particular warnings that a strong El Niño is on the way which could cause a strong rise in temperature in the course of 2026 and trigger further acceleration of the temperature rise. 

Indeed, the rise resulting from a strong El Niño would come on top of a temperature rise that is already accelerating due to high concentrations of greenhouse gases, while deforestation and numerous feedbacks are kicking in with greater ferocity, and while the temperature rise is amplified in the Arctic (see image below, from earlier post), which could lead to a Blue Ocean Event soon, further speeding up the temperature rise and resulting in loss of permafrost, eruption of methane from the seafloor of the Arctic Ocean, further loss of lower clouds, etc.


The above image, from an earlier post, shows that the 2025 Arctic temperature was 3.431°C higher than in 1951-1980. The only year on record that had an anomaly higher than 2025 was 2016, when there was a super El Niño.

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 - 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

• NOAA - Office of satellite and product operations - HEAP NUCAPS

• 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-y
and
• Global ocean heat content over the past 3 million years - by Sarah Shackleton et al.

• Earth Albedo - by Eliot Jacobson

• NASA - GISS Surface Temperature Analysis - custom plots
https://data.giss.nasa.gov/gistemp/graphs_v4/customize.html
quartic trend analysis was discussed earlier on facebook at: 

• NSIDC - Sea Ice Extent
https://nsidc.org/sea-ice-today/sea-ice-tools/charctic-interactive-sea-ice-graph

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

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

• Copernicus

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

• Moderate global warming does not rule out extreme global climate outcomes - by Emanuele Bevacqua et al.
https://www.nature.com/articles/s41586-026-10237-9
discussed on facebook at:
https://www.facebook.com/groups/arcticnews/posts/10164067383004679

• Measurement of Gas Fraction and Gas Permeability of Thawing Permafrost Caused by Climate Change - by Paul Glover et al. 
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025EF007232
Posted by at
Labels: , , , , , , ,

Thursday, May 22, 2025

Paris Agreement thresholds crossed (update May 2025)

High temperatures persist

In the image below, created with NASA data, the decade from 1904 through 1913 is used as a custom base, illustrating that the temperature anomaly has been more than 1.5°C above this base for each of the past consecutive 22 months (July 2023 through April 2025), and even longer when compared to a pre-industrial base. The red line shows a trend (two-year Lowess Smoothing) that is pointing at 2°C above this base (1904-1913) getting crossed in the course of 2026.

[ trend points at 2°C above 1904-1913 getting crossed in 2026 ]
The temperature rise on land looks even more threatening, as illustrated by the image below. 

The above image shows land only monthly temperature anomalies from 1880-1920, with the red line (2-year Lowess Smoothing trend) showing an acceleration in April 2022. If extended, the red line points at crossing 3°C in the course of 2026. Humans are likely to go extinct with a 3°C rise, as discussed in earlier posts such as this one. 

An earlier analysis mentions that, when using 1750 as a base, this could add 0.3°C to the historic rise. The analysis adds that when using an even earlier base, even more could be added to the historic temperature rise.

Those who seek to delay or sabotage climate action typically call for use of a late base, in efforts to minimize the historic temperature rise. Using an earlier base can mean that temperatures are already higher than the thresholds that politicians at the adoption of the Paris Agreement pledged wouldn't be crossed, and it can also imply that the temperature rise is accelerating faster and further, due to stronger feedbacks such as more water vapor in the atmosphere and disappearance of lower clouds, all of which would constitute a stronger call for climate action.

The image below illustrates that air temperatures in the Northern Hemisphere have been very high over the past few months, at times reaching record high temperatures for the time of year, e.g. the temperature in the Northern Hemisphere was 10.08°C on May 14, 2025, the highest temperature on record for that day.

[ from earlier post, click on images to enlarge ]

These record high temperatures are the more significant as they were reached under ENSO-neutral conditions. On May 24, 2025, the sea surface temperature was 27.51°C, 0.35°C below 1991-2020, in Niño 3.4, an area in the Pacific (inset) that is critical to the development of El Niño, as illustrated by the image below. The Niño 3.4 anomaly is now lower than it has been for each day in March 2025, when La Niña conditions dominated.


The ENSO outlook below is dated May 8, 2025. It shows that ENSO-neutral conditions are likely to persist for the remainder of 2025, edging on La Niña conditions.


The ENSO outlook is dated May 18, 2025.


As said, to see such high temperatures under ENSO-neutral conditions is significant, it indicates that feedbacks are stronger than many models have anticipated, which implies that feedbacks will continue to grow stronger, given the rapid temperature rise over the past few years (black trend). A new El Niño may develop soon, potentially in April 2026, as the red trend in the image below warns about. The result could be a huge rise in temperature over the course of 2026 (red trend).


As said, different bases can be used, e.g. in the above images anomalies are calculated versus bases such as 1904-1913, 1880-1920, 1991-2020 and 1901-2000. None of them is pre-industrial. So, what would the temperature anomaly look like when a genuinely pre-industrial base was used? 

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 an update, the same adjustments are made to data through April 2025.  


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.

IPCC keeps downplaying the danger

The IPCC keeps downplaying the danger in many ways. One way the IPCC does this is by selecting a base that minimizes the temperature rise and then to keep making the claim that we're still well below the 1.5°C threshold. The above image, from an April 2024 post, shows that the February 2024 temperature was 1.76°C above 1885-1915, and potentially 2.75°C above pre-industrial (bright yellow inset right). The red line (a six-months Lowess smoothing trend) highlights the steep rise that had already taken place by then. Minimizing the temperature rise will also minimize feedbacks that come with the temperature rise, such as a rise in water vapor and loss of lower clouds, which are self-amplifying feedbacks that further accelerate the temperature rise. In other words, by minimizing the historic temperature rise, the IPCC also seeks to minimize the rise to come. 

[ from a 2014 post, click on images to enlarge ]
An additional way used by the IPCC to downplay the danger is to suggest there was a "carbon budget", as if there was an amount of carbon to be divided among polluters that could continue to be consumed for decades to come.

The image on the right, from a 2014 post, points at the fallacy and deceit that comes with a carbon budget, carbon credits, offsets and net-zero emission targets that would, according to the IPCC, accomplish and maintain a "balance" between sources and sinks.

Instead, comprehensive and effective action is needed on multiple lines of action, simultaneously yet separately.

Indeed, action is needed to reduce concentrations of carbon both in oceans and in the atmosphere, while on land, the soil carbon content needs to increase, which can best be achieved by methods such as pyrolysis of biowaste and adding the resulting biochar to the soil, to reduce emissions, reduce fire hazards, sequester carbon, support the presence of moisture & nutrients in the soil and thus support the health & growth of vegetation, as discussed at the Climate Plan group and the biochar group.

The IPCC has failed on at least three points:
1. failed to warn about the historic temperature rise and associated larger feedbacks 
2. failed to warn about mechanisms that could cause further acceleration of temperature rise soon  
3. failed to point at the best ways to combat climate change.

Higher temperatures come with feedbacks, as illustrated by the image below, from an earlier post.

[ the temperature in the atmosphere can keep rising, even in the absence of further emissions ]
The above image illustrates how feedbacks and crossing of tipping points can cause the temperature of the atmosphere to keep rising, even in the absence of further emissions, due to shrinking heat sinks (e.g. sea ice thickness loss and oceans taking up less heat).

The IPCC failed to warn about Antarctic sea ice decline, and - importantly - the amplifying impact of Antarctic sea ice decline on the global temperature rise. This was addressed in an earlier post as follows:
Sea ice loss results in less sunlight getting reflected back into space and instead getting absorbed by the ocean and the impact of Antarctic sea ice loss is even stronger than Arctic sea ice loss, as Antarctic sea ice is located closer to the Equator, as pointed out by Paul Beckwith in a video in an earlier post. A warmer Southern Ocean also comes with fewer bright clouds, further reducing albedo, as discussed here and here. For decades, there still were many lower clouds over the Southern Ocean, reflecting much sunlight back into space, but these lower clouds have been decreasing over time, further speeding up the amount of sunlight getting absorbed by the water of the Southern Ocean, and this 'pattern effect' could make a huge difference globally, as this study points out. Emissivity is a further factor; open oceans are less efficient than sea ice when it comes to emitting in the far-infrared region of the spectrum (feedback #23 on the feedbacks page).

A 2024 study led by Norman Loeb finds that large decreases in stratocumulus and middle clouds over the sub-tropics and decreases in low and middle clouds at mid-latitudes are the primary reasons for increasing absorbed solar radiation trends in the northern hemisphere.

Slowing down of the Atlantic meridional overturning circulation (AMOC) can cause more heat to accumulate at the ocean surface. Higher sea surface temperatures also come with greater stratification (image below, from earlier post).

Stratification and further changes in oceans and in wind patterns can cause a freshwater lid to form on top of the ocean surface, enabling more hot & salty water to flow underneath this lid (feedback #28), contributing to calving of glaciers and destabilization of sediments at the seafloor.


Increases in water vapor in the atmosphere, loss of sea ice and loss of lower clouds are three self-amplifying feedbacks, i.e. as temperatures rise, such feedbacks will push temperature up even further and due to their self-amplification, the temperature rise will accelerate.

Sea ice loss

One feedback of high temperatures and high concentrations of greenhouse gases is loss of sea ice. Polar amplification of the temperature rise is hitting the Arctic hard, and is also causing dramatic loss of Antarctic sea ice. Global sea ice area has been very low for the past few years, as illustrated by the image below. This has caused a lot of sunlight that was previously reflected back into space, to instead get absorbed by the sea surface. On May 24, 2025, global sea ice area was 17.75 million km², lowest on record for the day.


The image below, adapted from the Danish Metereological Institute, shows that Arctic sea ice volume on May 29, 2025, was at a record low for the time of year, as it has been for more than a year.


Sea ice is disappearing over large parts of the Arctic Ocean. The image below, adapted from the University of Bremen, shows sea ice concentration on May 29, 2025.


The screenshot below, from an earlier post, further illustrates the dangers that come with sea ice loss. Eruptions of methane from the seafloor of the Arctic Ocean is one of the most terrifying dangers. 

As the image below illustrates, some of the thickest sea ice disappears from the Arctic Ocean as it gets broken up by sea currents and the pieces get moved out along the edges of Greenland. The image shows how, on May 27, 2025, the sea ice gets broken up just north of Greenland, due to ocean currents that will also move the pieces to the south, alongside the edges of Greenland, toward the North Atlantic.

[ click on images to enlarge ]

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

• NASA - datasets and images
https://data.giss.nasa.gov

• When Will We Die?
https://arctic-news.blogspot.com/2019/06/when-will-we-die.html

• Copernicus - Climate Pulse
https://pulse.climate.copernicus.eu

• Climate Reanalyzer
https://climatereanalyzer.org

• NOAA - Climate Prediction Center - ENSO: Recent Evolution, Current Status and Predictions
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

• NOAA - Climate Prediction Center - El Niño/Southern Oscillation (ENSO) Diagnostic Discussion

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

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

• NOAA - Office of Satellite And Product Operations - Sea Surface Temperatures
https://www.ospo.noaa.gov/products/ocean/sst/contour/index.html

• Nullschool.net
https://earth.nullschool.net

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

• Cold freshwater lid on North Atlantic
https://arctic-news.blogspot.com/p/cold-freshwater-lid-on-north-atlantic.html

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

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

• NASA - Worldview satellite images
https://worldview.earthdata.nasa.gov

• 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







Posted by at
Labels: , , , , , ,