Saturday, February 11, 2023

Will Steffen: The dilemma of pioneer climate scientists

 by Andrew Y Glikson

Will Lee Steffen: 25 June 1947 – 29 January 2023

The name of Will Lee Steffen will stand tall as a pioneer Earth systems and climate change scientist at our critical time when the life support systems of our planet are increasingly threatened. Along with other pioneer climate scientists over the last ~40 years or so, such as Wallace Broecker, James Hansen, Ralph Keeling, Paul Crutzen, Richard Alley, Stefan Rahmstorf, John Schellenberg, William Ruddiman, John Kutzbach, Guy Calendar, Michael Mann, Kevin Anderson, Andrew Weaver, Eric Rignot, Gavin Schmidt, Katrin Meissner, Kevin Trenberth and other, trying to communicate the scientific message of the greatest peril the planet is facing since at least 55 million years ago.

There cannot be a more painful position for scientists than to find themselves compelled to issue severe warnings of the demise of the natural world, civilization, society, family and future generations due to the sharp rise in greenhouse gas concentrations and temperatures originating from emissions from human industry. Yet this is precisely what climate scientists have been called to do, Cassandra-like, based on the physical and observed evidence for the rapid elevation in atmospheric, land and marine temperatures since the end of the 18th century at a rate exceeding geological mass extinction events.

Not all scientists have risen-up to the challenge. A small number have become climate change denial advocates, often supported by oil and gas corporations. Many in companies, government, institutions and in some instances even in universities had to subdue or moderate their warnings. Personal attitudes and politics became evident where, in some instances, scientists regarded as “optimists” were favoured by the authorities while other, labelled as “alarmists”, were penalized for their views. Nowadays the so-called “alarmists” are vindicated as extreme weather events are taking over large parts of the world.

Will Steffen avoided these pitfalls, sticking to the authentic scientific evidence and the manifest consequences of global warming around the world, yet disappointed by the refusal of many in authority to understand the implications of climate science for future generations, as reported in his communications (The Guardian 6/10/2018):
“I think the dominant linear, deterministic framework for assessing climate change is flawed, especially at higher levels of temperature rise. So, yes, model projections using models that don’t include these processes indeed become less useful at higher temperature levels. Or, as my co-author John Schellnhuber says, we are making a big mistake when we think we can “park” the Earth System at any given temperature rise – say 2C – and expect it to stay there … Even at the current level of warming of about 1C above pre-industrial, we may have already crossed a tipping point for one of the feedback processes (Arctic summer sea ice), and we see instabilities in others – permafrost melting, Amazon forest dieback, boreal forest dieback and weakening of land and ocean physiological carbon sinks. And we emphasise that these processes are not linear and often have built-in feedback processes that generate tipping point behaviour. For example, for melting permafrost, the chemical process that decomposes the peat generates heat itself, which leads to further melting and so on.”
Will Steffen wrote to me in our correspondence (27/03/2022):
“For all practical purposes i.e., timescales that humans can relate to, the levels of climate change we are driving towards now will be with us for thousands of years at least. The PETM (Palaeocene-Eocene thermal maximum) might be an appropriate analogue - a rapid spike in CO₂ concentration and temperature followed by the drawdown of CO₂ over 100,000 to 200,000 years. For all practical purposes, that time for recovery is so long (in human time scales) that it could be considered irreversible. Of course, extinctions are irreversible. So when the twin pressures of climate change and direct human degradation are applied to the biosphere, the resulting mass extinction event, that we have already entered, is of course irreversible.”
Will was one of a kind. While he would not let his presentations, expressed in scientifically objective and accurate terms, to be too coloured by optimism or pessimism, the congenial nature of his personality and gentle delivery could not hide the severe implications of his message. Rising above the fray, even his detractors found it difficult to refer to him in terms they commonly use toward other climate scientists. Nowadays in many forums climate scientists are replaced by economists, vested interests, marketing agents, sociologists and politicians, with only a vague idea of the basic laws of physics and the atmosphere.

Young generations, represented by Greta Thunberg, will see Will as one of last defenders of their future.

A/Professor Andrew Y Glikson
Earth and climate scientist
The University of New South Wales.
11 February 2023

Friday, February 3, 2023

Dire situation gets even more dire

Antarctic sea ice extent was 1.788 million km² on February 21, 2023, an all-time low in the NSIDC record.

Antarctic sea ice area was 1,050,708 km² on February 22, 2023, as illustrated by the Nico Sun image below.

This means that a huge amount of heat that was previously reflected back into space by the sea ice is now instead absorbed by the Southern Ocean, in a self-reinforcing feedback loop that results in further sea ice loss, in turn further speeding up the temperature rise and making the weather ever more extreme.

Arctic sea ice extent was 14,271,000 km² on February 19, 2023, the third-lowest extent in the NSIDC record for the time of year, as illustrated by the above image.

Global sea ice extent reached a record low of 15,500,000 km² on February 11, 2023, as illustrated by the above image.

The situation is dire

The dire situation is further illustrated by the image below, showing high sea surface temperature anomalies (from 1981-2011) over the Southern Ocean, the Atlantic ocean and the Arctic Ocean on February 19, 2023. 

Given the dire situation regarding sea ice and sea surface temperatures, Arctic sea ice may fall dramatically later in the year.

Furthermore, emissions, ocean heat and greenhouse gas levels all keep rising. 

Carbon dioxide (CO₂) at Mauna Loa, Hawaii, reached a record average daily high of 422.88 parts per million (ppm) on February 28, 2023, as illustrated by the above image and the image below. 

It is remarkable for CO₂ levels to already reach record high levels this early in the year, given that CO₂ levels typically reach their annual maximum in May. This spells bad news for developments over the next few months. Keep in mind that carbon dioxide reaches its maximum warming some 10 years after emission, so we haven't been hit by the full wrath of carbon dioxide pollution yet.

Possibly even worse is the rise in methane. The image below shows NOAA globally averaged marine surface monthly mean methane data from 2016, with methane reaching 1923.57 parts per billion (ppb) in November 2022. A moving average centered over 12 months is added to highlight the acceleration in the rise in methane.

Accordingly, temperatures keep rising. An earlier analysis concludes that we have already exceeded the 2°C threshold set at the Paris Agreement in 2015.

These dire conditions spell bad news regarding the temperature rise to come, the more so since, on top of these dire conditions, there are a number of circumstances, feedbacks and further developments that make the outlook even more dire.

Circumstances that make the situation even more dire

Firstly, as illustrated by the image on the right, adapted from NOAA, we're moving into an El Niño.

It looks like it's going to be a very strong El Niño, given that we've been in a La Niña for such a long time.

Moving from the bottom of a La Niña to the peak of a strong El Niño could make a difference of more than half a degree Celsius, as illustrated by the image below, adapted from NOAA.

[ click on images to enlarge ]

Temperature anomalies can be very high during an El Niño. The February 2016 temperature on land-only was 2.96°C above 1880-1920, and in February 2020, it was 2.79°C higher, as illustrated by the image below, created with screenshots taken on February 15, 2023. Note that 1880-1920 isn't pre-industrial.

Secondly, sunspots look set to reach a very high maximum by July 2025, as illustrated by the next two images on the right, adapted from NOAA.

Observed values for January 2023 are already well above the maximum values that NOAA predicted to be reached in July 2025.

If this trend continues, the rise in sunspots forcing from May 2020 to July 2025 may well make a difference of more than 0.25°C, a recent analysis found.

Thirdly, the 2022 Tonga submarine volcano eruption did add a huge amount of water vapor to the atmosphere.

Since water vapor is a potent greenhouse gas, this is further contributing to speed up the temperature rise.

A 2023 study calculates that the submarine volcano eruption near Tonga in January 2022, as also discussed at facebook, will have a warming effect of 0.12 Watts/m² over the next few years.

The image below, created with NOAA data, shows Annual Northern Hemisphere Land Temperature Anomalies and has two trends added. The blue trend, based on 1850-2022 data, points at 3°C rise by 2032. The pink trend, based on 2012-2022 data, better reflects variables such as El Niño and sunspots, showing that this could trigger a huge rise, with 3°C crossed in 2024. Anomalies are from 1901-2000 (not from pre-industrial).

Feedbacks and developments making things worse

Indeed, a huge temperature rise could be triggered, due to a multitude of feedbacks and further developments that could strongly deteriorate the situation even further.

On top of the water vapor added by the Tonga eruption, there are several feedbacks causing more water vapor to get added to the atmosphere, as discussed at Moistening Atmosphere.

Further feedbacks include additional greenhouse gas releases such as methane from the seafloor of the Arctic Ocean and methane, carbon dioxide and nitrous oxide from rapidly thawing permafrost on land.

The image below shows the Northern Hemisphere Ocean Temperature Anomaly, compared to 1901-2000. The pink trend, based on 1850-2022 data, shows that the Latent Heat Tipping Point (at 1°C) was crossed in 2022, but the red trend, based on 2007-2022 data, better reflects variables such as El Niño and shows both the Latent Heat Tipping Point and the Seafloor Methane Tipping Point (at 1.35°C) getting crossed in 2024. 

Ominously, November 2023 temperature anomalies are forecast to be at the top end of the scale for a large part of the Arctic Ocean, as illustrated by the image below. 

Some developments could make things even worse and a huge temperature rise could unfold soon. The image below shows a polynomial trend added to NOAA globally averaged marine surface monthly mean methane data from April 2018 to November 2022, pointing at 1200 ppm CO₂e (carbon dioxide equivalent) getting crossed in 2027.

The Clouds Tipping Point, at 1200 ppm CO₂e, could be crossed and this on its own could result in a further rise of 8°C. As illustrated by the above image, this tipping point could be crossed as early as in 2027 due to forcing caused by the rise in methane alone. When further forcing is taken into account, this could happen even earlier than in 2027. 

On top of the February 28, 2023 daily average of 422.88 ppm for CO₂, methane can add 384.71 ppm CO₂e when using a 1-year GWP of 200 for NOAA's 1923.57 ppb November 2022 methane mean.

While methane at higher altitude can reach even higher levels than NOAA's marine surface data, adding NOAA's November 2022 mean to 422.88 ppm CO₂ would leave just 392.41 ppm CO₂e for further forcing, before the Clouds Tipping Point would get crossed, as the image on the right illustrates.

[ see the Extinction page ]
Further forcing comes from nitrous oxide and other greenhouse gases, while rises in other gases and further changes such as caused by sea ice loss and changes in aerosols can also speed up the temperature rise.

Changes in aerosols are discussed in earlier posts such as this post and this post. The upcoming temperature rise on land on the Northern Hemisphere could be so strong that much traffic, transport and industrial activity will grind to a halt, resulting in a reduction in cooling aerosols that are now masking the full wrath of global heating. These are mainly sulfates, but burning of fossil fuel and biomass also emits iron that helps photosynthesis of phytoplankton in oceans, as a 2022 study points out. 

Without these emissions, the temperature is projected to rise strongly, while there could be an additional temperature rise due to an increase in warming aerosols and gases as a result of more biomass and waste burning and forest fires.

The image on the right, from the extinction page, includes a potential rise of 1.9°C by 2026 as the sulfate cooling effect falls away and an additional rise of 0.6°C due to an increase in warming aerosols by 2026, as discussed in this post and earlier posts.

The image on the right indicates that the rise from pre-industrial to 2020 could be as much as 2.29°C. Earth's energy imbalance has grown since 2020. Therefore, the rise up to now may be higher. 

Climate Tipping Points and further Events and Developments

The temperature could also be pushed up further due to reductions in the carbon sink on land. An earlier post mentions a study that found that the Amazon rainforest is no longer a sink, but has become a source, contributing to warming the planet instead; another study found that soil bacteria release CO₂ that was previously thought to remain trapped by iron; another study found that forest soil carbon does not increase with higher CO₂ levels; another study found that forests' long-term capacity to store carbon is dropping in regions with extreme annual fires; another earlier post discussed the Terrestrial Biosphere Temperature Tipping Point, coined in a study finding that at higher temperatures, respiration rates continue to rise in contrast to sharply declining rates of photosynthesis, which under business-as-usual emissions would nearly halve the land sink strength by as early as 2040.

This earlier post also discusses how CO₂ and heat taken up by oceans can be reduced. A 2021 study on oceans finds that, with increased stratification, heat from climate warming less effectively penetrates into the deep ocean, which contributes to further surface warming, while it also reduces the capability of the ocean to store carbon, exacerbating global surface warming. A 2022 study finds that ocean uptake of CO₂ from the atmosphere decreases as the Meridional Overturning Circulation slows down. An earlier analysis warns about growth of a layer of fresh water at the surface of the North Atlantic resulting in more ocean heat reaching the Arctic Ocean and the atmosphere over the Arctic, while a 2023 study finds that growth of a layer of fresh water decreases its alkalinity and thus its ability to take up CO₂, a feedback referred to as the Ocean Surface Tipping Point.

[ from Blue Ocean Event 2022? - click on images to enlarge ]

The above image depicts only one sequence of events, or one scenario out of many. Things may eventuate in different orders and occur simultaneously, i.e. instead of one domino tipping over the next one sequentially, many events may occur simultaneously and reinforce each other. Further events and developments could be added to the list, such as ocean stratification and stronger storms that can push large amounts of warm salty water into the Arctic Ocean.

While loss of Arctic sea ice and loss of Permafrost in Siberia and North America are often regarded as tipping points, Antarctic sea ice loss, and loss of the snow and ice cover on Greenland, on Antarctica and on mountaintops such as the Tibetan Plateau could also be seen as tipping points. Another five tipping points are: 
- The Latent Heat Tipping Point
- The Seafloor Methane Tipping Point


Altogether, the rise from pre-industrial to 2026 could be more than 18.44°C, while humans are likely to go extinct with a rise of 3°C, as illustrated by the image below, from an analysis discussed in an earlier post.

This should act as a warning that near-term human extinction could occur sooner than most may think. Indeed, when asked what could cause humans to go extinct, many may mention:
  1. asteroid strikes
  2. rampant pestilence, diseases, epidemics and pandemics
  3. war, murder and violence
  4. ecosystems and vegetation collapse, famine
  5. dehydration
  6. plastic pollution, spread of poisonous and toxic substances
  7. nuclear accidents, nuclear war or waste leakage
  8. outbreaks of antibiotic-resistant bacteria
  9. emerging new or re-emerging ancient microbes
10. bio-weapons and biological experiments gone out of hand
11. infertility, genetic degeneration, loss of genetic diversity
12. madness, cults, depression and suicide
13. polar shifts, earthquakes, landslides and tsunamis
14. Artificial Intelligence gone rogue
15. hostile aliens breeding predatory animals

More recently, climate change threats are mentioned such as:
16. destructive storms, flooding, fires and more extreme weather
17. hydrogen sulfide gas released from oceans
18. depletion of the ozone layer
19. co-extinctions, i.e. extinction of species that humans depend on, resulting in our own demise.

There may be more threats, but I think the biggest threat is:
20. temperature rise
In the video below, Edge of Extinction: Destination Destruction, Guy McPherson gives his view on our predicament.


The dire situation we're in looks set to get even more dire, calling for comprehensive and effective action, as described in the Climate Plan and Transforming Society.


• NSIDC - National Snow and Ice Data Center

• NSIDC - Chartic interactive sea ice graph

• Cryosphere Computing - by Nico Sun

• Nullschool

• Climate Reanalyzer - sea ice based on NSIDC index V3

• NOAA - greenhouse gases - trends

• NOAA - Climate Prediction Center - ENSO: Recent Evolution, Current Status and Predictions

• NOAA - Monthly temperature anomalies versus El Niño

• NOAA - Solar cycle progression

• NASA gistemp Monthly Mean Global Surface Temperature - Land Only

• NOAA - Annual Northern Hemisphere Land Temperature Anomalies 

• Tonga eruption increases chance of temporary surface temperature anomaly above 1.5 °C - by Stuart Jenkins et al. (2023)

• Moistening Atmosphere
• Albedo, latent heat, insolation and more

• Latent Heat

• Blue Ocean Event


• Methane keeps rising

• A huge temperature rise threatens to unfold soon

• The Clouds Feedback and the Clouds Tipping Point

• Human Extinction by 2025?

• 2020: Hottest Year On Record

• The Importance of Methane in Climate Change

• The underappreciated role of anthropogenic sources in atmospheric soluble iron flux to the Southern Ocean - by Mingxu Liu et al. (2022)

• How close are we to the temperature tipping point of the terrestrial biosphere? - by Katharyn Duffy et al. (2021)

• Overshoot or Omnicide? 

• Upper Ocean Temperatures Hit Record High in 2020 - by Lijing Cheng et al. (2021)

• Reduced CO₂ uptake and growing nutrient sequestration from slowing overturning circulation - by Yi Liu et al. (2022)

• Cold freshwater lid on North Atlantic
• Long-Term Slowdown of Ocean Carbon Uptake by Alkalinity Dynamics - by Megumi Chikamoto et al. (2023) 
• Ocean Surface Tipping Point Could Accelerate Climate Change

• When Will We Die?

• Edge of Extinction: Destination Destruction - video by Guy McPherson