Showing posts with label temperature. Show all posts
Showing posts with label temperature. Show all posts

Tuesday, August 5, 2025

Extreme weather gets more extreme

More than 43,000 homes lose power as Storm Floris brings gusts of up to 82 mph, says a BBC report of August 4, 2025. 

[ click on images to enlarge ]
As the temperature rise hits the Arctic harder than elsewhere in the world, the temperature difference between the North Pole and the Equator narrows, which slows down the jet stream and distorts its path, making the jet stream meander more. 

As the jet stream slows down, distortion can cause parts of the jet stream at times to move faster. In the above image on the left, the polar jet stream and the subtropical jet stream have merged over the Atlantic Ocean, reaching speeds as high as 302 km/h or 187 mph over the North Sea on August 5, 2025 01:00 UTC (green circle on above image left).


    [ click on images to enlarge ]
Furthermore, as temperatures rise and oceans heat up, the increased energy can at times strongly speed up ocean currents and winds. 

The above image shows sea surface temperatures as high as 32.7°C or 90.0°F, recorded south of Florida on August 3, 2025 12:00 UTC (at the green circle). The above image also shows the path of the Jet Stream (right) matching the path of the Gulf Stream (left), thus strengthening and speeding up the Gulf Stream and its extension North over the Atlantic Ocean and to the Arctic Ocean. 

The image on the right shows North Atlantic sea surface temperatures as high as 32.8°C on August 5, 2025, and the image on the right underneath illustrates the huge amounts of heat that have accumulated in the ocean, showing equivalent ocean heat content on August 5, 2025. 

Heat is moving up along the path of the Gulf Stream toward the Arctic, threatening to accelerate loss of sea ice and permafrost.

As temperatures rise, sea ice decline accelerates due to feedbacks such as the albedo feedback, i.e. less sunlight getting reflected by sea ice means more heat gets absorbed, further accelerating the temperature rise. 

The image below shows Arctic sea ice concentration on August 6, 2025. 


As illustrated by the image below, global sea ice extent was 21.89 million km² on August 5, 2025, a deviation of -4.71σ.


There are also tipping points, e.g. as sea ice volume declines over the years, the buffer disappears that previously consumed huge amounts of ocean heat in the process of melting the ice. 

Arctic sea ice volume was at a record daily low on August 6, 2025, as it has been for more than a year, as illustrated by the image below. 

    [ NOAA ENSO outlook ]
What makes the dire state of the sea ice even more significant is that there currently are no El Niño conditions. As illustrated by the image on the right, adapted from NOAA, the ENSO outlook (CFSv2 ensemble mean, black dashed line) favors borderline La Niña during the Northern Hemisphere fall and early winter 2025-2026.

The temperature rise is accelerating and the rise could accelerate even more due to such feedbacks, especially during an El Niño and due to further reduction of the aerosol masking effect, two developments that could rapidly speed up existing feedbacks and trigger new feedbacks. 

One of the most dangerous feedbacks is methane erupting from the seafloor of the Arctic Ocean. The image below shows hourly methane average recorded at the Barrow Atmospheric Baseline Observatory (BRW), a NOAA facility located near Utqiaġvik (formerly Barrow), Alaska, at 71.32 degrees North. 


The image below shows that the degree to which sulfate aerosols scatter and absorb light was as high as 4.500 τ on August 5, 2025, at 04:00 UTC at the location marked by the green circle.

[ sulfates contribute to the aerosol masking effect ]

The aerosol masking effect may be stronger than the IPCC's estimate, which would mean that the total warming due to people-caused emissions + feedbacks is higher. A 2022 study concludes that when ammonia, nitric acid and sulfuric acid are present together, they contribute strongly to the formation of cirrus clouds. Once released in the upper troposphere, ammonia can form particles with nitric acid, which is abundantly produced by lightning. As described in an earlier post, more burning of biomass and more extreme weather events such as forest fires and lightning can come with huge releases of gases and aerosols. Another earlier post shows how forest fires can come with high releases of sulfur dioxide, raising suspicions that forest fires can revolatilize sulfur emitted over decades from coal-fired power plants and settled on forest soil.

Sadly, the IPCC keeps downplaying the potential impact of feedbacks such as changes to ocean currents, wind patterns, clouds and water vapor, and loss of sea ice and permafrost, thus failing to warn people about a near-future in which temperatures could rise strongly due to such feedbacks, especially during an El Niño, and due to further reduction of the aerosol masking effect, developments that could rapidly speed up existing feedbacks and trigger new feedbacks, resulting in more extreme weather events striking with a ferocity, frequency and ubiquity that keeps increasing at an accelerating pace.

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

• More than 43,000 homes lose power as Storm Floris brings gusts of up to 82 mph - BBC August 4, 2025 

• NOAA - The Jet Stream

• University of Miami - Rosenstiel School - North Atlantic OHC

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

• NOAA - flask and station methane measurements
https://gml.noaa.gov/dv/iadv/index.php

• Synergistic HNO3 H2SO4 NH3 upper tropospheric particle formation - by Mingyi Wang et al. https://www.nature.com/articles/s41586-022-04605-4
discussed on facebook at:
https://www.facebook.com/groups/arcticnews/posts/10160005189729679




Saturday, July 12, 2025

Will humans go extinct soon?

The image below shows the June 2025 temperature anomaly versus 1951-1980, using ERA5 data.

[ June 2025 temperature anomaly, click on images to enlarge ]
    [ from earlier post, click to enlarge ]
The above image shows relatively low anomalies over the Arctic Ocean, with a relatively cool area persisting in the North Atlantic, south of Greenland. This appears to reflect heavy melting, slowing down of the Atlantic Meridional Overturning Circulation (AMOC) and strong evaporation followed by more rainfall further down the track of the Gulf Stream, as illustrated by the image on the right.

The above image also shows high anomalies over parts of Antarctica and Antarctic sea ice. This appears to reflect changes to the Southern Meridional Overturning Circulation (SMOC).

Rising temperatures result in a loss of carbon storage, concludes a recent study led by Thomas Werner into marine heatwaves. 

   [ marine heatwave in North Pacific ]
The image on the right shows that the sea surface temperature was as much as 7.5°C (13.4°F) higher than 1981-2011 on July 16, 2025, 12:00 UTC, at the location marked by the green circle, reflecting a strong marine heatwave in the North Pacific. The image also shows a distorted Jet Stream (at 250 hPa).

Covering more than 70% of Earth’s surface, our global ocean has absorbed 90% of the warming that has occurred in recent decades due to increasing greenhouse gases, and the top few meters of the ocean store as much heat as Earth's entire atmosphere, as described by a NASA post

A small reduction in the 90% uptake of heat by oceans could result in a huge rise in the global air temperature, and studies warn about changes that are occurring in the AMOC and SMOC, as discussed in earlier posts such as this one. Such feedbacks could strike hard very rapidly, i.e. as fast feedbacks. 

The IPCC (AR6 WG1 SPM page 11) uses an equilibrium climate sensitivity of 3°C, but James Hansen says fast-feedback equilibrium climate sensitivity is 4.8°C and equilibrium global warming for today’s amount of greenhouse gases (4.1 W/m²) is 10°C, which includes a 2°C rise that would eventuate by the falling away of the aerosols that currently mask the temperature rise. 

A 2024 study led by Judd finds that climate sensitivity has historically been about 8°C. 

[ Temperature rise vs 1901-2000 (ClimateReanalyzer) and vs 1850-1900 (IPCC, inset left) ]

The IPCC appears to be downplaying the temperature rise in multiple ways, including by using linear trends, a late baseline and a low climate sensitivity, to give the false impression that polluters could continue to pollute for decades to come. 
 
The above images illustrate what the world would look like under a CMIP6 SSP5-8.5 scenario by February 2100, compared to 1891-1910. Obviously, such a rise would devastate sea ice and permafrost, triggering and accelerating numerous feedbacks, resulting in widespread forest fires and releases of greenhouse gases.


The 36-month running average for albedo (reflectivity) for May 2025 is down to a record low of 28.711%, as illustrated by the above Eliot Jacobson image.


The 36-month running mean for the Earth energy imbalance grew in May 2025 to 11.36 Hiroshimas per second. That's roughly 980,000 Hiroshimas per day in planetary warming, adds Eliot Jacobson.

As said, the IPCC keeps downplaying the potential impact of feedbacks such as changes to ocean currents, wind patterns, clouds and water vapor, and loss of sea ice and permafrost, thus failing to warn people about a near-future in which temperatures could rise strongly due to such feedbacks, especially during an El Niño, and due to further reduction of the aerosol masking effect, developments that could rapidly speed up existing feedbacks and trigger new feedbacks, resulting in more extreme weather events striking with a ferocity, frequency and ubiquity that keeps increasing at an accelerating pace.

   [ NOAA ENSO outlook ]
The updated ENSO outlook (CFSv2 ensemble mean, black dashed line, image on the right, adapted from NOAA) favors borderline La Niña during the Northern Hemisphere fall and early winter 2025-2026.

The image below illustrates the outlook of borderline La Niña for the Northern Hemisphere fall and early winter 2025-2026. On July 29, 2025, the average temperature in Niño 3.4, an area in the Pacific that is indicative for El Niño development (inset), had fallen to 26.7°C, an anomaly of -0.35°C from 1991-2020.


The current ENSO conditions make it even more significant that on July 14, 2025, the global temperature was 16.86°C, i.e. higher than the temperature was in 2023 or 2024 on this day, as illustrated by the image below, adapted from Climate Reanalyzer. 


The earlier image below shows a preliminary 16.85°C that was later upgraded to 16.86°C (final). The point is that this is a record high for that day and 0.3°C below the highest daily temperature on record (17.16°C) that was reached on July 22, 2024 (image adapted from Copernicus).

The image below shows monthly temperature anomalies through June 2025, based on ERA5 anomalies vs 1951-1980 from Jan 2014-June 2025 (red circles). 
In the above image, data are adjusted by 1°C to reflect a pre-industrial base (black circles). Cubic trends are added to show that 3°C could be crossed late 2028 (red) or early 2027 (black). 

The image below shows surface air temperature anomalies April 1, 2023, through July 14, 2025 (final), with a red trend added that warns about a potentially huge temperature rise later in 2025.


Furthermore, sea surface temperatures are on the rise again. The image below shows the global sea surface temperature through July 20, 2025 (60°S–60°N, 0–360°E).


How much could temperatures rise? The image below is a combination image. The top image shows a trend based on annual sea surface temperature anomalies in the Northern Hemisphere through 2022. The bottom image shows a trend based on annual sea surface temperature anomalies in the Northern Hemisphere through 2023. The trend in the bottom image shows an even steeper rise than the trend in the top image. This shows that a polynomial trend can sometimes be a good indicator of the rise to come.


The current ENSO conditions also make it even more significant that the global sea ice area anomaly was 2.56 million km² below the 1981-2010 mean on July 30, 2025, a standard deviation of -4.33σ from 1981-2010.
Global sea ice extent was 21.92 million km² on July 31, 2025, a deviation of -4.88σ, as illustrated by the image below. 


Arctic sea ice volume was at a record daily low on August 3, 2025, as it has been for more than a year, as illustrated by the image below.

The image below shows Arctic sea ice concentration on August 3, 2025.


Seafloor methane

As the temperature of the water of the Arctic Ocean rises, more ocean heat can penetrate sediments at the seafloor of the Arctic Ocean, which can destabilize methane hydrates contained in these sediments and cause eruptions of huge amounts of methane from the hydrates and from free gas kept underneath these hydrates.

The image below shows that methane concentrations as high as 2535 parts per billion (ppb) were recorded at a pressure level of 695.1 mb by the NOAA 20 satellite on July 30, 2025 AM. High concentrations of methane show up at latitudes higher than 30°N.


The image below shows hourly methane measurements taken at the Barrow Atmospheric Baseline Observatory (BRW), a NOAA facility located near Utqiaġvik (formerly Barrow), Alaska, at 71.32 degrees North.


The image below repeats the IPCC's response, or rather its failure to respond.


A 3°C rise constitutes an important threshold, since humans will likely go extinct with such a rise. As illustrated by the image below, we may already be more than 2°C above pre-industrial and face a potentially huge temperature rise over the next few years.

[ from the post When will humans go extinct? ]
   [ from: When Will We Die? ]
Recent research led by David Fastivich finds that, historically, vegetation responded at timescales from hundreds to tens of thousands of years, but not at timescales shorter than about 150 years. It takes centuries for tree populations to adapt - far too slow to keep pace with today’s rapidly warming world.

Note that vegetation depends on the presence of a lot of things including healthy soil, microbes, moisture, nutrients and habitat. 

A 2018 study by Strona & Bradshaw indicates that most life on Earth will disappear with a 5°C rise (see box on the right). Humans, who depend on a lot of other species, will likely go extinct with a 3°C, as discussed in the earlier post When Will We Die? 

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

• Climate Reanalyzer
https://climatereanalyzer.org

• IPCC AR6 WG1 Figure 4.35 | Comparison of RCPs and SSPs
https://www.ipcc.ch/report/ar6/wg1/downloads/figures/IPCC_AR6_WGI_Figure_4_35.png
https://www.ipcc.ch/report/ar6/wg1/figures/chapter-4/figure-4-35

• Saltier water, less sea ice
https://arctic-news.blogspot.com/2025/07/saltier-water-less-sea-ice.html

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

• Marine heatwaves as hot spots of climate change and impacts on biodiversity and ecosystem services - by Thomas Wernberg et al.
discussed on Facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10162992131044679

• Copernicus
https://pulse.climate.copernicus.eu

• NASA - Ocean warming (December 2024) 
https://climate.nasa.gov/vital-signs/ocean-warming/?intent=121

• Arctic Blue Ocean Event 2025? (update June 2025)
https://arctic-news.blogspot.com/2025/06/arctic-blue-ocean-event-2025-update-June-2025.html

• A 485-million-year history of Earth’s surface temperature - by Emily Judd et al. (2024) 
https://www.science.org/doi/10.1126/science.adk3705
discussed on Facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10161741588279679

• Global warming in the pipeline - by James Hansen et al. 
https://academic.oup.com/oocc/article/3/1/kgad008/7335889
discussed on Facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10161110558744679


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

• 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

• When will humans go extinct? 

• Coupled, decoupled, and abrupt responses of vegetation to climate across timescales - by David Fastovich et al. (2025)
discussed on Facebook at: 

• Danish Meteorological Institute - sea ice thickness and volume
• University of Bremen
https://seaice.uni-bremen.de/start

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

• NOAA - satellite methane measurements
https://www.ospo.noaa.gov/products/atmosphere/soundings/heap/nucaps/new/nucaps_products.html

• NOAA - flask and station methane measurements
https://gml.noaa.gov/dv/iadv/index.php

• When Will We Die?

• 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




Saturday, May 3, 2025

Arctic sea ice May 2025

[ Arctic sea ice thickness, click on images to enlarge ]
The above combination image shows Arctic sea ice thickness on March 13, 2025 (left), April 28, 2025 (center) and May 13, 2025 (right). The image on the right shows more open water off the coast of Siberia.


[ Arctic sea ice concentration ]
The above image is a screenshot of part of a NASA Worldview satellite image for May 1, 2025. The image similarly shows open water off the coast of Siberia. The red dots indicate fires. 

The image on the right, adapted from NSIDC, shows Arctic sea ice concentration on May 13, 2025. 

Arctic sea ice is under threat as numerous conditions are becoming increasingly dire, as discussed in earlier posts such as this one

For some of these conditions, further updates are added below (carbon dioxide, temperature, variables and Arctic sea ice). 

Carbon dioxide

A daily carbon dioxide (CO₂) concentration of 431.25 parts per million (ppm) was recorded on May 10, 2025, at Mauna Loa, Hawaii, the highest daily average on record. 
CO₂ concentrations haven't been below 430 ppm for 14 days in a row at Mauna Loa, Hawaii, as illustrated by the above image, which shows CO₂ for the last 31 days through May 10, 2025. The image below gives another view of daily concentrations. 

One has to go back millions of years in time to find CO₂ concentrations this high, while the impact of high CO₂ concentrations back in history was lower due to lower solar output and the rate of change was also much slower, as also discussed in an earlier post.

The image below illustrates that the weekly mean CO₂ concentration at Mauna Loa, Hawaii, was 430.60 ppm in the week beginning on April 27, 2025, i.e. 4.02 ppm higher than the weekly value from one year ago (green inset).
Weekly CO₂ for the week starting May 4, 2025, was 430.86 ppm at Mauna Loa, Hawaii, compared to 426.92 ppm one year ago, a difference of 3.94 ppm, as illustrated by the image below.


The annual global average surface concentration of carbon dioxide (CO₂) for 2024 was 422.79 parts per million (ppm). CO₂ concentrations grew by 3.75 ppm during 2024, the highest growth rate on record, as discussed in an earlier post.

Temperature 

The global surface air temperature was 15.72°C on 9 May 2025, the highest temperature on record for this day, as illustrated by the image below. 

The global surface air temperature was 15.75°C on 10 May 2025, again the highest temperature on record for this day. The image below shows ERA5 daily temperature anomalies from end 2022 through May 10, 2025, with two trends added, a black linear trend and a red cubic (non-linear) trend that reflects stronger feedbacks and that follows ENSO (El Niño/La Niña) conditions more closely. This red trend warns about further acceleration of the temperature rise.


The shading added in the above image reflects the presence of El Niño conditions that push up temperatures (pink shading), La Niña conditions that suppress temperatures (blue shading), or neutral conditions (gray shading). The trends warn about feedbacks and further mechanisms pushing up temperatures over the next few years.

The above image shows two bases to compare the anomalies with, 1991-2000 (left axis) and 1901-1930 (right axis). Neither of these two bases is pre-industrial, anomalies will be higher when using a genuinely pre-industrial base. 

The image below shows NASA monthly data through April 2025 compared to a custom 1903-1924. This 1903-1924 base is not pre-industrial either, anomalies will be higher when using a genuinely pre-industrial base. The monthly temperature anomaly has now been more than 1.5°C higher than this 1903-1924 base for 22 consecutive months (July 2023 through April 2025, marked with red text). Anomalies are rising rapidly, the red line (2-year Lowess Smoothing trend) points at 2°C higher than 1903-1924 getting crossed in the course of 2027.

[ more than 1.5°C above base for 22 consecutive months, trend points at 2°C above 1903-1924 crossed in 2027 ]
The picture can change when using a different base that anomalies are compared with. To illustrate this, the image below uses the decade from 1904 through 1913 as a custom base, resulting in higher anomalies and a trend 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 ]
An earlier analysis of pre-industrial suggests that using 1750 as a base could add as much as 0.3°C to the historic rise, while using a 3480 BC base could add as much as 0.79°C to the historic rise. 

Those who seek to sabotage climate action typically call for use of a base that minimizes the historic temperature rise. A higher historic rise can imply 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 more due to stronger feedbacks such as more water vapor in the atmosphere and disappearance of lower clouds, so that would constitute a stronger call for climate action. 

The Arctic is hit hardest by the temperature rise, as illustrated by the image below, which shows temperature anomalies compared to 1951-1981 for the period from November 2024 through April 2025. 


The image below illustrates that the global temperature was at a record high for the time of year for five days in a row, i.e. from April 24, 2025, through April 28, 2025.

Variables

Some variables have a short-term impact on the temperature rise, including volcanoes, sudden stratospheric warming, sunspots and El Niño/La Niña variations. There have been no volcano eruptions and no sudden stratospheric warming events recently that could have provided significant cooling. Sunspots are at a high point in this cycle, which pushes up temperatures. Regarding ENSO (El Niño-Southern Oscillation), current conditions are ENSO-neutral, highlighting the significance of the high current temperatures, while a new El Niño may emerge soon. The image below shows NOAA's ENSO outlook dated May 11, 2025.


The image below shows temperatures through May 9, 2025, in Niño 3.4, an area in the Pacific (inset) that is critical to the development of El Niño.

[ temperature in Niño 3.4 area ]

Mechanisms such as self-amplifying feedbacks and crossing of tipping points, and further developments such as loss of the aerosol masking effect, can jointly contribute to further accelerate the temperature rise, resulting in a rise from pre-industrial of more than 10°C, while in the process also causing the clouds tipping point to get crossed and that can push the temperature rise up by a further 8°C, as discussed in earlier posts such as this one.

Arctic sea ice volume and area

Loss in sea ice can dramatically push up temperatures, as discussed in earlier posts such as this one. High ocean temperatures are causing Arctic sea ice volume to be very low compared to earlier years. The image below shows Arctic sea ice volume over the years in red for April, the month when Arctic sea ice typically reaches its maximum volume for the respective year. 

The image below shows Arctic sea ice volume from 2000, with markers indicating volume in September (red) and in April (blue), corresponding to the year's minimum- and maximum volume. 
The image below shows Arctic sea ice volume through May 14, 2025.
The image below illustrates that Arctic sea ice disappears not only as it melts away from below, due to heating up of the water of the Arctic Ocean. Arctic sea ice can also disappear as it gets broken up by ocean currents and moves out of the Arctic Ocean. The image shows how, on May 6, 2025, the sea ice gets broken up just north of the northern tip 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 ]
On May 13, 2025, Arctic sea ice area was second lowest on record for that day, as illustrated by the image below. 
The comparison with the year 2012 is important, since Arctic sea ice area reached its lowest minimum in 2012. Arctic sea ice area was only 2.24 million km² on September 12, 2012, i.e. 1.24 million km² above a Blue Ocean Event. While on May 13, 2025, Arctic sea ice area was only 0.8 million km² lower than on May 8, 2012, the difference between anomalies typically gets narrower in May. Therefore, if the difference between 2025 and 2012 will widen again, a Blue Ocean Event may occur in September 2025, as discussed in an earlier post

Methane

Loss of Arctic sea ice can also trigger a very dangerous feedback: eruptions of methane from the seafloor of the Arctic Ocean. Methane in the atmosphere is already very high and large additional methane releases threaten to cause hydroxyl depletion, in turn extending the lifetime of all methane currently in the atmosphere. 

Data for the annual increase in methane have been updated by NOAA. in 2024, there was a higher increase than in 2023, the 2024 increase was almost 10 parts per billion (ppb).   

The image below shows the annual methane increase data (red circles), with two trends added. A quadratic trend (blue) is based on all available data (1894 through 2024), while a quintic trend (pink) is based on 2017 through 2024 data. The pink trend warns about a huge increase in methane, which could eventuate due to eruptions of seafloor methane.

Below are warnings from earlier posts. 
[ from earlier post, also note the recent discussion on monthly methane ]
[ from earlier post ]
Also noteworthy is this analysis by Andrew Glikson and work by Peter Wadhams et al. 

In the video below, methane emissions are discussed by Peter Wadhams, Paul Beckwith, Peter Carter and Herb Simmens
 

Methane concentrations in the atmosphere have been around 1960 parts per billion (ppb) recently at Mauna Loa, Hawaii, as illustrated by the image below. 

Methane is more potent as a greenhouse gas than carbon dioxide. Methane also has indirect effects, such as ground-level ozone and stratospheric water vapor, while methane partly turns into carbon dioxide. Importantly, the warming potential of a pulse of methane will decrease over time, given methane's relatively short lifetime. 

Accordingly, there are different ways to calculate methane's carbon dioxide equivalent (CO₂e). Also important is whether a specific concentration of methane is used (in ppb) or the weight is used of a pulse of methane. In each of these cases, different multipliers can be used to calculate methane's CO₂e.

When using a multiplier of 200, a methane concentration of 1960 ppb would translate into 392 ppm of CO₂e. As mentioned above, a daily CO₂ concentration of 431.25 ppm was recorded at Mauna Loa, Hawaii, on May 10, 2025. So, when adding up these two, the joint CO₂e would be 823.25 ppm CO₂e, i.e. just 376.75 ppm short of the clouds tipping point (at 1200 ppm). This joint total doesn't yet include contributions of nitrous oxide and other drivers, so the situation is even more dire. Moreover, concentrations of greenhouse gases are increasing and they may increase even more dramatically soon.

So, what multiplier is best used when calculating methane's CO₂e? The IPCC already uses a slightly higher GWP for methane emissions from fossil fuel fugitive emission sources than for other methane emissions. So, the idea of using different multipliers in different scenarios is not new. 

One multiplier could be used that does include cooling aerosols and another one that doesn't. Most carbon dioxide results from burning coal and oil, which comes not only with high CO₂ emissions, but also with co-emissions of cooling aerosols. On the other hand, there are little or no cooling aerosols co-emitted with methane emissions. Therefore, inclusion of cooling aerosols could result in a higher multiplier to be used when translating concentrations of methane into CO₂e, compared to carbon dioxide.

[ warming contributions, from earlier post, click on images to enlarge ]

[ warming responsibility by sector ]
To illustrate this point, the above image shows contributions to warming from 2010 to 2019, using IPCC AR6 data. If masking (cooling) would be included in the image by subtracting cooling by sulfates from CO₂, then the contribution of CO₂ would be proportionally lower, while the contribution of methane would be proportionally higher than what the image shows. 

The image on the right is from a recent analysis by Gerard Wedderburn-Bisshop.    

Given the dire outlook and given methane's higher potency as a greenhouse gas, it makes most sense to seek urgent and dramatic reductions in methane and such action should not be allowed to be sabotaged by those who propose a low multiplier when calculating methane's CO₂e.

IPCC

Meanwhile, the IPCC remains silent. No updates or special reports on topics such as acceleration of the temperature rise. Instead, the IPCC keeps persisting in downplaying the potential for such dangerous developments (in terms of the severity, probability, ubiquity and imminence of their impact), in efforts to hide the most effective climate action. The IPCC keeps pointing at less effective policies such as support for BECCS and biofuel, while continuing to make it look as if there was a carbon budget to divide among polluters, as if polluters could continue to pollute for decades to come.

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 also discussed at this group.



Links

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

• NASA Worldview
https://worldview.earthdata.nasa.gov

• NSIDC - National Snow and Ice Data Center - Sea Ice Today
https://nsidc.org/sea-ice-today


• NOAA - Daily Average Mauna Loa CO2
https://gml.noaa.gov/ccgg/trends/monthly.html

• NOAA - Weekly Average Mauna Loa CO2

• Climate Reanalyzer
https://climatereanalyzer.org

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

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

• Record high increase in carbon dioxide
https://arctic-news.blogspot.com/2025/04/record-high-increase-in-carbon-dioxide.html

• NOAA - ENSO: Recent Evolution, Current Status and Predictions - 5 May 2025
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

• NOAA - trends in methane
https://gml.noaa.gov/ccgg/trends_ch4

• The methane time bomb - by Andrew Glikson (2018)

• Copernicus
https://climate.copernicus.eu

• Increased transparency in accounting conventions could benefit climate policy - by Gerard Wedderburn-Bisshop