Showing posts with label Jemma Wadham. Show all posts
Showing posts with label Jemma Wadham. Show all posts

Thursday, December 15, 2022

Antarctic sea ice in rapid decline


Earlier this year, on February 25, Antarctic sea ice extent was at an all-time record low of 1.924 million km², as the above image shows. Throughout the year, Antarctic sea ice extent has been low. On December 14, 2022, Antarctic sea ice was merely 9.864 million km² in extent. Only in 2016 was Antarctic sea ice extent lower at that time of year, and - importantly - 2016 was a strong El Niño year.

The NOAA image on the right indicates that, while we're still in the depths of a persistent La Niña, the next El Niño looks set to strike soon.

Meanwhile, ocean heat content keeps rising due to high levels of greenhouse gases, as illustrated by the image on the right. 

Rising ocean heat causes sea ice to melt from below, resulting in less sea ice, which in turn means that less sunlight gets reflected back into space and more sunlight gets absorbed as heat in the ocean, making it a self-reinforcing feedback loop that further speeds up sea ice loss. 

The currently very rapid decline in sea ice concentration around Antarctica is illustrated by the animation of Climate Reanalyzer images on the right, showing Antarctic sea ice on November 16, November 29 and December 15, 2022.

In 2012, a research team led by Jemma Wadham studied Antarctica, concluding that an amount of 21,000 Gt or billion tonnes or petagram (1Pg equals 10¹⁵g) of organic carbon is buried beneath the Antarctic Ice Sheet, as discussed in an earlier post. 

The potential amount of methane hydrate and free methane gas beneath the Antarctic Ice Sheet could be up to 400 billion tonnes. 

The predicted shallow depth of these potential reserves also makes them more susceptible to climate forcing than other methane hydrate reserves on Earth, describes the news release. 

“We are sleepwalking into a catastrophe for humanity. We need to take notice right now. It is already happening. This is not a wait-and-see situation anymore," Jemma Wadham said more recently.

The animation on the right shows the thickness of Antarctic sea ice up to December 14, 2022, with 8 days of forecasts added.  

On December 29, 2022, Antarctic sea ice extent was at a record low for the time of the year, at 5.527 million km² (see image on the right). 

Recently, a study discovered a process that can contribute to the melting of ice shelves in the Antarctic, as discussed at the ArcticNews group. 

Ominously, high concentrations of methane have been recorded over Antarctica recently. The image below shows methane as recorded by the Metop-B satellite on November 28, 2022 pm at 399 mb. 

Global sea ice extent was also at a record low for the time of year on December 29, 2022, at 17.53 million km², as illustrated by the image below, by the National Institute of Polar Research, Japan. 


The situation is dire and the right thing to do now is to help avoid or delay the worst from happening, through action as described in the Climate Plan.


Links

• NSIDC - Interactive sea ice graph
https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph

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

• NOAA - ocean heat content
https://www.ncei.noaa.gov/access/global-ocean-heat-content/index.html

• Climate Reanalyzer sea ice concentration
https://climatereanalyzer.org/wx/todays-weather/?var_id=seaice-snowc&ortho=7&wt=1

• Naval Research Laboratory - Antarctic sea ice 
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/antarc.html

• Potential methane reservoirs beneath Antarctica - Press release University of Bristol (2012)
https://www.bristol.ac.uk/news/2012/8742.html

• Potential methane reservoirs beneath Antarctica - by Jemma Wadham et al. (2012)
https://www.nature.com/articles/nature11374

• A new frontier in climate change science: connections between ice sheets, carbon and food webs

• Ocean variability beneath Thwaites Eastern Ice Shelf driven by the Pine Island Bay Gyre strength - by Tiago Dotto et al.
https://www.nature.com/articles/s41467-022-35499-5

• Metop-B satellite readings

• National Institute of Polar Research, Japan
• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html



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Wednesday, February 9, 2022

Accelerating loss of global snow and ice cover


Ocean heat is at record levels. As a result, global sea ice extent was only 16.23 million km² on February 9, 2022, the third lowest extent on record. What makes this even more worrying is that we're currently in the depth of a persistent La Niña.


Antarctic sea ice at lowest extent on record since start satellite measurements

Ocean heat is a huge threat for Antarctica at the moment. The image below shows that Antarctic sea ice extent was only 2.091 million km² on February 16, 2022, the lowest on record since the start of satellite measurements.


Ocean heat is reducing the sea ice around Antarctica and is getting underneath floating sea ice. 

The Thwaites Glacier, which is on a retrograde slope, is especially vulnerable to collapse. 

The Thwaites Glacier contains enough ice to raise global sea levels by 65 cm (25.59 inches) if it were to completely collapse.

The animation on the right, created with images from Climate Reanalyzer, shows the retreat of the Antarctic snow and ice cover from January 5 to February 18, 2021. 

The animation underneath, by navy.mil, shows sea ice thickness over 30 days up to February 17, 2022 (with 8 days of forecasts added).

Another danger of a rapid loss of the snow and ice cover on Antarctica is release of methane. Jemma Wadham warned about this in a 2012 study, as discussed at the post methane hydrates. More recently, Jemma Wadham said: “We are sleepwalking into a catastrophe for humanity.”

The Thwaites Glacier is often called the Doomsday Glacier because if it collapses it would lead to vast sea level rise, and scientists believe it is likely to fail within a few years, says Cliff Seruntine (the Naturalist) in the video below. 


A recent study concludes that mountain glaciers may hold less ice than previously thought. Their disappearance means less water for drinking and agriculture, and faster temperature rises due to albedo loss. While the study found that the Himalayas contain more water than thought, another recent study, Mt. Everest’s highest glacier is a sentinel for accelerating ice loss, describes how human-induced climate change has a huge impact on the highest reaches of the planet.

The outlook for the Arctic is most threatening, as the post methane hydrates also concluded back in 2013, as described in numerous post here at Arctic-news and as discussed in the video below by Jim Massa.


A huge temperature rise threatens to unfold soon


Above image indicates that the difference between the top of El Niño and the bottom of La Niña could be more than half a degree Celsius.

As said, we're currently in the depth of a persistent La Niña, which suppresses temperatures. As the temperature keeps rising, ever more frequent strong El Niño events are likely to occur, as discussed in an earlier post. 

A 2019 study analyzes how tipping the ENSO into a permanent El Niño can trigger state transitions in global terrestrial ecosystems.

Currently, the temperature rise is additionally suppressed by low sunspots. Within a few years time, sunspots can be expected to reach the peak of their current cycle and observed sunspots are looking stronger than predicted. 

In the image below on the right, adapted from NOAA, the solar cycle is represented as the number of sunspots (top) and F10.7cm radio flux (bottom). 

In a recent communication, James Hansen repeats that, as reductions take place in the sulfate aerosols that are currently co-emitted by traffic, transport and industry, this is causing the current temperature rise to accelerate and could cause further rapid global warming, referred to in a 2021 presentation as a termination shock.

Furthermore, in addition to a huge temperature rise resulting from sulfate aerosols falling away, there could be a further rise in temperature as a result of releases of other aerosols with a net warming impact, such as black and brown carbon, which can increase dramatically as more wood burning and forest fires take place.

In summary, while the temperatures are accelerating, we'll soon be moving into the next El Niño, with sunspots moving toward a peak, with sulfate aerosols causing a termination shock and with other aerosols further driving up the temperature rise. 

Stop the deception!

In a giant scheme of deception, the temperature rise is all too often presented with images of people playing on the beach on a 'warm' day, as if 'global warming' was making life more 'comfortable'. 

Forest fires are called 'wildfires', biomass burning and associated deforestation is referred to as 'renewable biofuel', fracking-induced earthquakes are called 'natural' disasters and methane eruptions are called seeps and bubbles of 'natural' gas from 'natural' sources such as wetlands. 

This gives the false impression that this was somehow 'natural' as if human activities had nothing to do with it, and as if owning beach-front property was becoming ever more attractive.


Let's stop this deception! In reality, human-caused emissions have a huge short-term impact on temperature and their combination with genuinely natural variability such as El Niño and sunspots can act as a catalyst, causing numerous feedbacks to kick in with ever greater ferocity. 

This can result in collapse of global sea ice and permafrost, resulting in albedo loss and eruption of huge quantities of carbon dioxide, methane and nitrous oxide, further driving up the temperature rise abruptly, as described at the extinction page. Further feedbacks are also described at the feedbacks page. 

Conclusion

The situation is dire and calls for the most comprehensive and effective action, as described at the Climate Plan.


Links

• Another Record: Ocean Warming Continues through 2021 despite La Niña Conditions - by Lijing Cheng et al. 
https://link.springer.com/article/10.1007%2Fs00376-022-1461-3

• Ocean heat is at record levels, with major consequences - by Kevin Trenberth

• Arctic Data archive System - Vishop extent

• NSIDC: Charctic Interactive Sea Ice Graph

• IPCC: Marine Ice Sheet Instability

• Climate Reanalyzer
https://climatereanalyzer.org/wx/DailySummary/#seaice-snowc-topo

• Antarctica CICE ice thickness

• Antarctica’s ‘doomsday’ glacier: how its collapse could trigger global floods and swallow islands 
https://theconversation.com/antarcticas-doomsday-glacier-how-its-collapse-could-trigger-global-floods-and-swallow-islands-173940

• Methane hydrates (2013)

• Potential methane reservoirs beneath Antarctica - by Jemma Wadham et al. (2012) 
https://www.nature.com/articles/nature11374

• A new frontier in climate change science: connections between ice sheets, carbon and food webs (2021) 

• Ice velocity and thickness of the world’s glaciers - by Romain Millan et al. 
https://www.nature.com/articles/s41561-021-00885-z

• Mountain glaciers may hold less ice than previously thought – here’s what that means for 2 billion downstream water users and sea level rise 
https://theconversation.com/mountain-glaciers-may-hold-less-ice-than-previously-thought-heres-what-that-means-for-2-billion-downstream-water-users-and-sea-level-rise-176514

• Mt. Everest’s highest glacier is a sentinel for accelerating ice loss - by Mariusz Potocki et al. 

• Human-induced climate change impacts the highest reaches of the planet — Mount Everest
• Ocean Heat Content Update 1 - 2022 - Science Talk with Jim Massa
https://www.youtube.com/watch?v=pctkg_LDqcU

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

• NOAA - Monthly Temperature Anomalies Versus El Niño 
• Human Extinction by 2022? 

• Tipping the ENSO into a permanent El Niño can trigger state transitions in global terrestrial ecosystems - by Mateo Duque-Villegas et al. (2019) 
https://esd.copernicus.org/articles/10/631/2019

• James Hansen - The New Horse Race

• Climate Impact of Decreasing Atmospheric Sulphate Aerosols and the Risk of a Termination Shock - by Leon Simons, James Hansen and Yann duFournet (2021) 

• NOAA - Solar Cycle Progression

• Aerosols

• Feedbacks

• Extinction




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