Arctic News

Friday, May 3, 2024

Is CMIP6 SSP585 the worst-case scenario?

The image below, adapted from Climate Reanalyzer, shows the temperature in the year 2100, in a CMIP6 SSP585 scenario. The image shows how much the temperature will have risen in 2100, at 2 meters above the surface and compared to the period 1979-2000.

The image below shows a progressive temperature rise reaching 4.589°C in 2100 compared to the same period, i.e. 1979-2000 and in a CMIP6 SSP585 scenario.

The 1979-2000 period is relatively recent. The temperature has been rising for longer than that. The image below shows a progressive temperature rise reaching 4.91°C by 2100 in a CMIP6 SSP585 scenario when instead using a 1901-2000 period as a base.

The 1901-2000 period is also relatively recent, much later than pre-industrial. When using a pre-industrial base, the temperature rise will be well over 5°C.

As illustrated by the top image, the temperature rise over land will be much higher than over oceans, which makes the situation even more dire, given that most people live on land and could face a rise of 8°C by 2100 in a CMIP6 SSP585 scenario.

In a CMIP6 SSP585 scenario, temperatures are projected to keep rising strongly beyond 2100, as illustrated by the image below, from a 2016 paper by Brian O'Neill et al.

In the study by Brian O'Neill et al., CO₂ emissions keep rising until 2100, to then fall gradually to current levels, while the CO₂ concentration in the atmosphere keep rising, to remain at levels beyond 2000 ppm and result in a temperature rise of 8°C by 2300 in a CMIP6 SSP585 scenario.

Is CMIP6 SSP585 the worst-case scenario?

To check whether CMIP6 SSP585 is indeed the worst-case scenario, one can look at how fast CO₂ is rising. According to the IEA, global energy-related CO₂ emissions grew in 2023, reaching a new record high of 37.4 Gt (or 10.098 GtC). The image below, from a recent post, confirms the recent acceleration in CO₂ concentrations, while showing the potential for CO₂ concentration to cross 1200 ppm before the year 2060.

In other words, CO₂ may well be rising even faster than anticipated in a CMIP6 SSP585 scenario, while this scenario doesn't take into account the potential for CO₂e concentrations to cross 1200 ppm much earlier than 2100 (inset), e.g. before 2060 as illustrated by the red trend in the main image. Furthermore, CMIP6 SSP585 doesn't take into account that, in addition to the temperature rise resulting from high greenhouse gas concentrations, crossing the clouds tipping point at 1200 ppm in itself would push up temperatures by a further 8°C.

Indeed, the clouds tipping point could be crossed even earlier when also taking into account methane, nitrous oxide and further greenhouse gases, while there are additional developments such as carbon release from soils that could further raise both CO₂ concentrations and temperatures. The Extinction page and posts such as this one and this one warn about the potential for a temperature rise of well over 18°C unfolding as early as 2026.

The IPCC has persistently downplayed the potential for these dangerous developments. The IPCC keeps hiding the need for the most effective climate action, while the IPCC instead keeps pointing at less effective policies such as support for BECCS and biofuel, and while the IPCC also keeps making it look as if there was a carbon budget to divide among polluters, as if polluters could continue to pollute for decades to come, as discussed in earlier posts such as this one.

Meanwhile, a 2018 study (by Strona & Bradshaw) indicates that most life on Earth will disappear with a 5°C rise. Humans, who depend for their survival on many other species, will likely go extinct with a 3°C rise, as illustrated by the image below, from an earlier post.

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

• The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6 - by Brian O'Neill et al. (2016)

https://gmd.copernicus.org/articles/9/3461/2016

• International Energy Agency (IEA) - CO2 Emissions in 2023 report
https://www.iea.org/reports/co2-emissions-in-2023

• September 2023, highest anomaly on record?

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

Tuesday, April 30, 2024

Temperature rise in the Tropics (update 5)

The temperature in the Tropics (23.5°S-23.5°N, 0-360°E) reached a new record high on April 24, 2024 of 27°C (or 80.6°F).

The image below shows the monthly temperature anomaly over the past few years through March 2024, when the anomaly reached a record high of 1.448°C (or 2.606°F).

Note that the anomaly in the top image is calculated from 1979-2000 as a base, while anomalies in the above image are calculated from 1951-1980 as a base. When calculated from a pre-industrial base, these anomalies will be much higher.

The high temperatures are causing widespread damage and are threatening to cause huge loss of life of people, livestock and wildlife, crop failure and ecosystem collapse in the tropics and elsewhere.

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

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

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

• Transforming Society

https://www.facebook.com/SamCarana/posts/10169053955465161 (update 5: Apr 24, 2024)

https://www.facebook.com/SamCarana/posts/10169050918525161 (update 4: Apr 23, 2024)

https://www.facebook.com/SamCarana/posts/10169042787710161 (update 3: Apr 20, 2024)

https://www.facebook.com/SamCarana/posts/10168930859815161 (update 2: Mar 12, 2024)

https://www.facebook.com/SamCarana/posts/10168929028460161 (update 1: Mar 11, 2024)

https://www.facebook.com/SamCarana/posts/10168860099940161 (update: Feb 14, 2024)
https://www.facebook.com/SamCarana/posts/10168858418170161 (Feb 13, 2024)
https://www.facebook.com/SamCarana/posts/10168795048860161 (Jan 22, 2024)

Arctic sea ice under threat

The image below indicates that Arctic sea ice volume has meanwhile passed its annual maximum. Over the coming months, volume can be expected to decrease rapidly. The image also highlights that, over the past few months, Arctic sea ice volume has been the lowest on record for the time of year.

The image below illustrates the decline of Arctic sea ice volume over the years. The image also confirms that the annual maximum volume was recently reached and that it was the lowest maximum for the 24 years on record.

Given that Arctic sea ice currently is still relatively extensive, this record low volume indicates that sea ice is indeed very thin, which must be caused by ocean heat melting sea ice from below, since little or no sunshine is yet reaching the Arctic at the moment and air temperatures are still far below freezing point, so where ocean heat may be melting sea ice away from below, a thin layer of ice will quickly be reestablished at the surface, keeping sea ice extent relatively large for now.

This situation looks set to dramatically change over the next few months, as air temperatures will rise and as more ocean heat will reach the Arctic Ocean. Moreover, as illustrated by the map below, much of the thicker sea ice is located off the east coast of Greenland. This sea ice and the purple-colored sea ice can be expected to melt away quickly with the upcoming rise in temperatures over the next few months.

Sea surface temperatures at record high

The image below, created with Climate Reanalyzer screenshots, shows that the sea surface temperature (SST 60°S - 60°N mean) was 21.2°C on April 24, 2024, reaching yet another record high.

[ image from earlier post ]

These record high sea surface temperatures are reached as long-term sea surface temperatures are falling and as El Niño is predicted to weaken, which is fueling fears that feedbacks are kicking in with accelerating ferocity.

The image below, adapted from NOAA, shows global ocean temperature anomalies from 1901-2000, with the green line (LOcally Estimated Scatterplot Smoothing) giving a warning that higher temperature anomalies could be coming up.

[ image from earlier post ]

The image below shows that the monthly Atlantic surface temperature anomaly in March 2024 was 1.422°C when compared to a 1901-2000 base.

The high anomalies over the past two months indicate how much heat has accumulated in the Atlantic, and these anomalies are even higher when using a pre-industrial base, as discussed earlier.

The images also highlight the potential for the slowing down of the Atlantic meridional overturning circulation (AMOC) to contribute to more heat accumulating at the surface of the Atlantic Ocean.

Arctic sea ice under threat

As temperatures rise, many feedbacks are kicking in with greater ferocity, including increased stratification of oceans, loss of sea ice, loss of reflectivity of clouds and increased freshwater due to stronger melting of sea ice and glacial ice, due to heavier runoff from land and rivers and due to changes in ocean circulation.

While this may look to cause less ocean heat to reach the Arctic Ocean for now, the result is that a huge amount of ocean heat is accumulating in the North Atlantic that threatens to abruptly move into the Arctic Ocean. The danger is that an influx of ocean heat can cause large amounts of methane to erupt from the seafloor of the Arctic Ocean.

An enormous amount of ocean heat has accumulated and is still further accumulating in the North Atlantic and much of this heat threatens to abruptly move into the Arctic Ocean. The danger is that, due to strong wind along the path of the Gulf Stream and extensions of this current into the Arctic Ocean, huge amounts of ocean heat will abruptly get pushed into the Arctic Ocean, with the influx of ocean heat causing destabilization of hydrates contained in sediments at the seafloor of the Arctic Ocean, resulting in eruptions of huge amounts of methane.

The danger is growing, due to a number of factors. Firstly, the amount of ocean heat in the North Atlantic is increasing. Secondly, Arctic sea ice volume is at record low, implying that there is little or no buffer left to consume ocean heat flowing from the Atlantic Ocean into the Arctic Ocean.

Latent heat is energy associated with a phase change, such as the energy consumed when solid ice turns into water (i.e. melts). During a phase change, the temperature remains constant. Sea ice acts as a buffer that absorbs heat, while keeping the temperature at zero degrees Celsius. As long as there is sea ice in the water, this sea ice will keep absorbing heat, so the temperature doesn't rise at the sea surface.

The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C.

The danger is that, as the buffer disappears that until now has consumed huge amounts of ocean heat, further heat will reach methane hydrates at the seafloor of the Arctic Ocean, causing them to get destabilized resulting in release of methane from these hydrates and from free gas underneath that was previously sealed by the hydrates.

[ The Buffer has gone, feedback #14 on the Feedbacks page ]

Strong hurricanes can significantly add to the danger. More hurricanes are forecast for the 2024 Atlantic hurricane season than during 1950-2020, as illustrated by the image below, from an earlier post.

Many of the dangers have been discussed in earlier posts, e.g. the danger that sea currents in the Arctic Ocean will change direction was discussed in this 2017 post.

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

• NOAA - Ocean temperature anomalies
https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/global/time-series/globe/ocean/1/0/2015-2024?filter=true&filterType=loess

• Atlantic ocean heat threatens to unleash methane eruptions
https://arctic-news.blogspot.com/2024/03/atlantic-ocean-heat-threatens-to-unleash-methane-eruptions.html

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

• North Atlantic heating up
https://arctic-news.blogspot.com/2024/04/north-atlantic-heating-up.html

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

• 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

Monday, April 29, 2024

Temperature rise in the Tropics (update 4)

The temperature in the Tropics (23.5°S-23.5°N, 0-360°E) reached a new record high on April 23, 2024 of 26.925°C (or 80.47°F).

The image below shows the monthly temperature anomaly over the past few years through March 2024, when the anomaly reached a record high of 1.448°C (or 2.606°F).

Note that anomalies in the above image are calculated from 1951-1980 as a base. When calculated from a pre-industrial base, anomalies will be much higher.

The high temperatures are causing widespread damage and are threatening to cause huge loss of life of people, livestock and wildlife, crop failure and ecosystem collapse in the tropics and elsewhere.

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.

• Transforming Society

https://www.facebook.com/SamCarana/posts/10169050918525161 (update 4: Apr 23, 2024)

https://www.facebook.com/SamCarana/posts/10169042787710161 (update 3: Apr 20, 2024)

https://www.facebook.com/SamCarana/posts/10168930859815161 (update 2: Mar 12, 2024)

https://www.facebook.com/SamCarana/posts/10168929028460161 (update 1: Mar 11, 2024)