Coral reef ecosystems on the way to being cooked

The accelerating heat content of the world’s oceans will soon be forcing coral reef ecosystems towards their collapse into mass extinction

Click here for a detailed explanation of the graph

Views expressed in this post are those of its author(s), not necessarily all Vote Climate One members.

European Space Agency research on rising sea-levels

The European Space Agency presents some of its satellite-based research programs on ice melting and rising sea levels..

by Space for Our Climate 10/02/2022 — European Space Agency
New research sums up sea-level rise: Sea-level rise is arguably one of the most serious consequences of the climate crisis. While using satellite data to monitor how the height of the sea is changing provides critical evidence for decision-making, satellites are also essential to measuring the individual components, such as seawater temperature and glacier melt, that contribute to the overall rise. Confidence in the accuracy of these separate measures is key. ESA-funded research now confirms that the figures match up.

Views expressed in this post are those of its author(s), not necessarily all Vote Climate One members.

Rising sea-level risk: can’t know when or how much

Melting polar glaciers are main contributors to rising sea level. The melting process is highly non-linear and thus inherently unpredictable

At least since the 1800s, world sea levels have been rising gradually but at a slowly accelerating rate. Since in the last 140 years it has risen around 17 cm, with around 6 cm of that in the 20 years between 2000 and 2020. And this is only a small part of the hugely complex planetary climate system that has an inherently unpredictable capacity to produce abrupt and catastrophically large changes in climate conditions.

Shows a slow acceleration in the rate of sea level rise.

The rising sea-level has two sources: runoff from the land (mostly glacial melt water) and thermal expansion of the ocean itself due to warming from excess solar energy accumulating from the global warming process.

Sourced from East Coast flooding is a reminder that sea level is rising as the climate warms – here’s why the ocean is pouring in more often – by Jianjun Lin, 07/11/2021 in the Conversation.

The melt water in the rising sea-level comes from two primary sources, melting glaciers and ice cap on Greenland that has increased 6-fold over the last couple of decades; and melting glaciers and ice cap on Antarctica which has more than doubled over the same time. This is measured by the loss of mass variable – representing the weight of the water that has been added to the oceans.

As described in the feature article below, the melting rate of a glacier is determined by its speed as it is creeping/sliding down the continental slope into the ocean. This in turn is determined by a complex set of interacting factors, e.g., temperature, angle of slope, width and roughness of the bed, how much meltwater is in the bed to lubricate/float the ice, where and how the ice may crack and crumble, how many bends there are in the valley, ocean conditions at the foot, whether and to what extent warm and salty (salt lowers the melting temperature of ice) ocean water penetrates into the glacier bed under its foot, thickness and extent of the floating ice shelf at the glacier’s foot and so on. Simply stated, melt rates are inherently unpredictable. However, one thing we can be sure of is that the melt rate will speed up as ambient temperatures increase the rate of ice melting, and rain replaces snow as the main form of precipitation.

The geological record provides good evidence that episodes of abrupt ice melting can cause raise sea-levels a lot faster than they are now, perhaps even showing large changes in rate over a few decades.

See Wikipedia: Meltwater pulse 1A: Meltwater pulse 1A (MWP1a) is the name used by Quaternary geologists, paleoclimatologists, and oceanographers for a period of rapid post-glacial sea level rise, between 13,500 and 14,700 years ago, during which global sea level rose between 16 meters (52 ft) and 25 meters (82 ft) in about 400–500 years, giving mean rates of roughly 40–60 mm (0.13–0.20 ft)/yr…. This rate of sea level rise was much larger than the rate of current sea level rise, which has been estimated to be in the region of 2–3 mm (0.0066–0.0098 ft)/yr.

There may well be enough ice in the West Antarctic Ice Sheet — especially if combined with an equally rapid melting of the Greenland Ice Sheet to support an equivalent amount of melting to the Meltwater Pulse 1A. It is notable that the land surface underlying very large areas of both West Antarctica and Greenland are below sea level – giving ample opportunities for warm ocean water to help speed the melting and collapse of the ice sheets.

Glacier front meets the sea

Why Melting Ice in Antarctica is Making Waves: Scientists recently discovered that the Thwaites Ice Shelf, a floating ice shelf that supports the Florida-sized Thwaites Glacier, could collapse in as little as five years because of global warming.

Climate Reality Project, 28/01/2022

This past December, the massive Thwaites Glacier in Western Antarctica made headlines for all the wrong reasons. Specifically, because new research revealed that the ice shelf preventing it from sliding into the ocean and drastically raising sea levels could collapse well within the next decade.

This Florida-sized glacier had already worried experts for years, going as far as to regularly be called the “Doomsday Glacier”. And yet, this update from the scientific community was still groundbreaking. 

It’s news that the world — particularly low-lying island and coastal communities — should understand and act on. So, what exactly is Thwaites Glacier, what does the latest research about it say, and what consequences could come from its decline?


Thwaites Glacier is a massive body of dense ice located in Western Antarctica. Measuring about 80 miles (120 km) across, it’s the widest glacier on Earth.

Decline of West Antarctic Glaciers Appears Irreversible

Thwaites Glacier in Western Antarctica. Credit: NASA

The glacier has an ice shelf — a permanent piece of floating ice connected to it — that branches out into the Amundsen Sea. Now, understanding what exactly an ice shelf does is crucial.

Read the complete article….

As long as the world continues to warm and large amounts of snow and ice remain lying on the land, sea levels will continue to rise. The risk of an abrupt sea-level rise is real. The human and economic costs of such an event would be catastrophic if it happens. It therefore makes very good sense that mitigation works should begin soon with planning in place at federal, state and local levels to accelerate the work if we have any clear early warning signs that abrupt melting is actually beginning.

It is also clear that our present LNP COALition governments deeply deny the risks Australia faces from global warming and the climate emergency, and should be replaced with rational people who put action on the climate emergency at the top of their to do lists if they should be elected to Parliament.

The puppets show and tell
Captain Humbug (A.K.A. Scotty from Marketing) showing the parliamentary puppet troop what it is all about behind his then PM, “Don’t be afraid, don’t be scared, it won’t hurt you. It’s coal.” With these words Australia’s Treasurer Scott Morrison taunted the Opposition, attempting to ridicule its commitment to renewable energy.” – Picture from The Conversation (15-02-2017). See also Katherine Murphy in The Guardian on 09/02/2017 for the live video — “Scott Morrison brings coal to question time: what fresh idiocy is this? What a bunch of clowns, hamming it up – while out in the real world an ominous and oppressive heat just won’t let up.”

Also, from the official transcript dated 20/12/2019 from the PM’s own office, Scotty made it abundantly clear to John Stanley on 2GB Radio that HE doesn’t fight fires… “But I know Australians understand… that, you know, I don’t hold a hose, mate, and I don’t sit in a control room. That’s the brave people who do that are doing that job. But I know that Australians would want me back at this time out of these fatalities. So I’ll happily come back [from his secret holiday in Hawaii] and do that.”

Sixteen year-old Greta tells us and everyone at the 2019 World Economic Forum in Davos how we and our governments should actually respond to the climate emergency:

Listen to Greta’s speech live. Except for her reliance on the IPCC’s overoptimistic emissions budget, everything she says is spot on that even she, as a child, can understand.

In other words, smell the smoke, see the reality, and fight the fire that is burning up our only planet so we can give our offspring a hopeful future. This is the only issue that matters. All Capt. Humbug and his troop of wooden-headed puppets are doing is rearranging the furniture in the burning house to be incinerated along with anything else we may care about. In Greta’s words, “even a small child can understand [this]”. People hope for their children’s futures. She doesn’t want your hope. She wants you to panic enough to wake up and fight the fire…. so she can have some hope for her future. Vote Climate One’s Traffic Light Voting System will help you use your vote wisely on behalf of our offsprings’ futures.

Views expressed in this post are those of its author(s), not necessarily all Vote Climate One members.

What was extreme in the past for the world’s oceans is now the normal

by Carolyn Gramling, 01/02/2022 in Science News
The past’s extreme ocean heat waves are now the new normal: More than half the global ocean experiences high temperatures that were rare a century ago.

See also 2021 might not have been the hottest year on record, but the heating oceans are hotter than ever

Views expressed in this post are those of its author(s), not necessarily all Vote Climate One members.

Dying coral reefs and collapsing reef ecosystems: evidence of more progress towards the point of no return on the way to Hothouse extinction

Part 5 of David Spratt’s guidebook to events along the road to Hothouse Hell: Increasingly frequent and stronger marine heatwaves are bleaching and killing corals, architects of reef ecosystems. Rotting organic matter emits GHGs

Coral polyps are the primary architects of the remarkably diverse coral reef ecosystems that border lands and islands in tropical oceans around the world. As such coral reefs provide shelter and sustenance for a significant fraction of our ocean’s biomass for at least part of their lives. Coral polyps are colonial animals related to jellyfish and sea anemones. However, thanks to symbiotic algae that live in their bodies, they are sinks for capturing and sequestering CO₂ in forming the limestone reefs. Over the last 10,000 years or so, they have thrived in waters close to the maximum temperatures their photosynthetic algae can tolerate. However, as the world begins to warm beyond temperatures observed for many 10s of thousands of years corals have had to expel their algae and become bleached. As Spratt describes, bleaching is becoming common event for the Great Barrier Reef, and is leading to dying coral reefs and collapsing reef ecosystems around the world.

As masses of polyps die and rot they become net greenhouse gas emitters (CO₂, methane, hydrogen sulfide – H₂S – where the H₂S is also highly toxic) and end up covered by slimes of bacteria and algae. The dead reef becomes quite toxic, and loses many of the species that originally thrived there through starvation, poisoning, or loss of habitat. Thus, the rising greenhouse gas emissions from dying and decomposing reef ecosystems adds yet another source of positive feedback to drive global temperatures (including ocean temperatures) higher yet.

Great Barrier Reef bleaching 2016

28 January 2022

Have tipping points already been passed for critical climate systems? (5) Coral Reefs: A death spiral

by David Spratt in Climate Code Red
Fifth in a series.
Read 1  |  2  |  3  |  4  |  5  |  6  |  7

Ecosystems, including coral reefs, mangroves and kelp forests in Australia, are degrading fast as the world’s sixth mass extinction gathers pace. 


Corals survive within a narrow water temperature band, and suffer heat stress and expel zooxanthellae if the ocean temperature gets too high. Bleaching events vary in intensity; in the extreme case, all zooxanthellae are expelled and the living colony will appear totally white (hence “bleaching”).  As elevated sea temperatures persist, coral mortality rates increase: corals may recover, if there are any zooxanthellae left in their tissues, but if not, death appears to be inevitable. 

The bottom line: If severe bleaching events occur regularly at shorter than 10–15 year intervals, then reefs face a death spiral of coral mortality followed by inadequate recovery periods. And that is what is happening now. Along Australia’s Great Barrier Reef, the frequency of mass bleaching is increasing, with events occurring in 1998, 2002, 2016, 2017 and 2020.  The 2016-17 events severely bleached half the reef, whose extent has been reduced by three-quarters over the last 40 years. Coral reproduction on the Great Barrier Reef has fallen 89% after repeated recent bleachings.  [My emphasis]

Read the complete article….

Analyses published yesterday shows that it is probably already too late to save dying coral reefs and reef ecosystems (including the Great Barrier Reef) from terminal collapse in the next decade or two

One of these articles is referenced in today’s The Age newspapers.

James Cook University marine biologist Jodie Rummer at work on the Great Barrier Reef. She has witnessed previous bleaching and described it as “scary and disturbing”.Credit:Grumpy Turtle

No climate change refuge for coral reefs: study

by Miki Perkins, 02/02/2022 in The Age

Global warming of 1.5 degrees above pre-industrial levels will be catastrophic for almost all coral reefs, including those that scientists once hoped would act as refuges during climate change.

Only 0.2 per cent of coral reefs globally are likely to avoid frequent heat stress if temperatures warm, according to new research from an international team of universities, including James Cook University in Townsville.

Even thermal refuges, which experts assumed would be more able to endure warming oceans owing to factors such as the consistent upwelling of cool deep waters, would provide almost no protection to reef animals, the study found. It is published today in PLOS Climate.

Read the complete article….

Actually, there were two articles on rapidly rising sea surface temperatures (SST) published yesterday in the science journal, PLOS Climate. Together they seem to seal the fate of most of our planet’s coral reef ecosystems:

Future loss of local-scale thermal refugia in coral reef ecosystems

by Adele M Dixon, et al., 01/02/2022 in
PLOS Climate –

Global distribution of exposure category in the 1986–2019 climate and at 1.5 and 2.0°C of future global warming. [DHW is the sum of SST anomalies 1°C higher than the long-term maximum monthly mean (MMM) over a 12-week period] Exposure categories are thermal refugia (probability of DHW events > 4°C-weeks less than 0.1 yr‒1), intermediate (probability of DHW events > 4°C-weeks from 0.1–0.2 yr‒1) and exposed (probability of DHW events > 4°C-weeks greater than 0.2 yr‒1). Percentages indicate the regional (on map) and global (right of map) proportion of thermal refugia (blue) and exposed reefs (red). The 12 coral reef regions are outlined in light blue. The base map is made with Natural Earth.

ABSTRACT: Thermal refugia underpin climate-smart management of coral reefs, but whether current thermal refugia will remain so under future warming is uncertain…. We confirm that warming of 1.5°C relative to pre-industrial levels will be catastrophic for coral reefs….

Read the complete article…..

The recent normalization of historical marine heat extremes

by K. Tanaka & Kyle S. Van Houtan 01/02/2202 in
PLOS Climate –

Decadal evolution of frequency of extreme marine heat from 1980–2019. Extreme heat defined as exceeding the localized (1° × 1°), monthly, 98th percentile of sea surface temperatures (SST) observed during 1870–1919, averaged from HadISSTv1.1 and COBESSTv2 products. Extreme heat, resolved for boreal winter (Jan-Mar) and summer (Jul-Sep), accumulates steadily over time beginning in the Southern, South Atlantic, and Indian basins. Regions of the mid North Atlantic and eastern South Pacific indicate a low occurrence. The base map layer was drawn using the “rworldmap” R package (

ABSTRACT: Climate change exposes marine ecosystems to extreme conditions with increasing frequency…. For the year 2019, our index reports that 57% of the global ocean surface recorded extreme heat, which was comparatively rare (approximately 2%) during the period of the second industrial revolution. Significant increases in the extent of extreme marine events over the past century resulted in many local climates to have shifted out of their historical SST bounds across many economically and ecologically important marine regions. For the global ocean, 2014 was the first year to exceed the 50% threshold of extreme heat thereby becoming “normal”….

Read the complete article….

The bottom line: It is almost certainly too late to save the Great Barrier Reef we know from ecological collapse, but we might be able to save keystone species able to rebuild it if we can stop and reverse global warming

Given that we have probably already crossed several tipping points such as permafrost thawing on the road to runaway global warming where natural positive feedbacks will continue working to drive global temperatures ever higher, the Great Barrier Reef as we know it seems to be unavoidably doomed. However, as long as a majority of the keystone architect coral species survive somewhere, they may be able to recolonize their previous ranges and begin building new reefs over subsequent centuries.

Unfortunately, when we should be working all-out to stop anthropogenic greenhouse gas emissions, our present Australian Government lead by Capt. Humbug (AKA Scotty from Marketing) and his deputy Blarny Barney (the Man with the Hat) is working hard to grow and maintain the healthy capacity of the fossil fuel industry to produce and burn carbon for energy. Also, not only are they doing nothing practical to stop and reverse global warming, but they just promised to spend a billion dollars on the Reef (over 9 years) to cloak the fact that they are doing nothing that counts to save the Reef (or for that matter our own human species).

The rapidly approaching Federal Election gives us the opportunity to remove Capt. Humbug and his wooden headed puppets from office and replace them with trustworthy, thinking people who have committed themselves to put work to solve the climate crisis as their first order of business if elected to Parliament. Vote Climate One’s Traffic Light Voting System is designed to help you do this.

Views expressed in this post are those of its author(s), not necessarily all Vote Climate One members.

We shouldn’t forget – Antarctic ice is also melting

Zach Labe is always a good source of graphics summarizing collections of data on our changing climate Here he shows the melting of sea ice around Antarctica. The horizontal line shows the average extent of sea ice over the era of satellite measurements (beginning in 1978). The red line shows how much smaller extent of sea ice this January so far.

Views expressed in this post are those of its author(s), not necessarily all Vote Climate One members.

2021 wasn’t hottest year, but oceans are hottest ever

As the world warms, oceans store an ever more solar energy to increase global ocean heating and polar ice melting.

As the following article explains, thanks to the continuing rise in the greenhouse effect caused by the continuing rise in concentrations of CO₂ and methane, our planet continues to capture more solar heat that it can radiate away to space. Some of this excess increases air temperatures. However, most of the excess solar energy goes into ocean heating. Hot oceans heat Earth. The warmer water can melt polar ice covers and heat can be stored for slow release into the terrestrial environment and atmosphere over many years.

The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content (OHC).

Another Record: Ocean Warming Continues through 2021 despite La Niña Conditions

by Lijing, et al., 11/01/2022 in
Advances in Atmospheric Sciences

Abstract: The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content (OHC). Here, we provide the first analysis of recent OHC changes through 2021 from two international groups. The world ocean, in 2021, was the hottest ever recorded by humans, and the 2021 annual OHC value is even higher than last year’s record value…. The long-term ocean warming is larger in the Atlantic and Southern Oceans than in other regions and is mainly attributed, via climate model simulations, to an increase in anthropogenic greenhouse gas concentrations. The year-to-year variation of OHC is primarily tied to the El Niño-Southern Oscillation (ENSO). In the seven maritime domains of the Indian, Tropical Atlantic, North Atlantic, Northwest Pacific, North Pacific, Southern oceans, and the Mediterranean Sea, robust warming is observed but with distinct inter-annual to decadal variability. Four out of seven domains showed record-high heat content in 2021. The anomalous global and regional ocean warming established in this study should be incorporated into climate risk assessments, adaptation, and mitigation.

Read the complete article….

Excess heat in the oceans will continue to drive further global warming even if we stop all anthropogenic greenhouse gas emissions.

The accumulating heat in the ocean serves as a source of positive feedback to drive global temperatures even higher.

  • By melting sea ice – the warm water melts ice cover that used to reflect solar heat away from the ocean, allowing it to be absorbed tin warm the water further
  • By further warming the atmosphere to spread excess heat to the land to warm soils, increase wildfires, thaw permafrost, and warm wetlands – all increasing ‘natural’ greenhouse gas emissions to trap more solar heat
  • By reducing the solubility of CO₂ and other greenhouse gases in seawater – driving them into the atmosphere where they contribute to further warming and ocean heating
  • By reducing oxygenation to produce ‘dead zones’ where animals and green plants are suffocated to die and decompose anaerobically producing methane and poisonous sulfide gases.

In other words, even without an annual record high air temperature, the process of global warming is accelerating and becoming progressively more difficult to stop and reverse. Unless we mobilize and act soon and vigorously to resolve the climate crisis, enough solar energy will be captured to ensure that the warming process continues. Even if we stop all human carbon emissions the warming will be driven by positive feedbacks from the warm oceans. Beyond stopping human emissions we need to deploy global geoengineering projects. First to capture and sequester greenhouse gases (e.g., by fertilizing the ocean deserts and farming phytoplankton together with ecosystems of plankton eaters able to send much of the carbon fixed by the algae to the bottom sediments of the oceans in the form of feces and dead bodies). And, secondly, to help the Earth reflect more solar heat back to space (e.g., by making the atmosphere more reflective with aerosols such as calcium carbonate).

Australia’s current COALition Government in Canberra is controlled by Captain Humbug (i.e., Scotty from Marketing) and his fellow puppets and clowns of the fossil fuel special interests. They have been working for years to subsidize and protect their puppet masters’ industry from being shut down or even being inconvenienced by actions against global warming. If we are to act effectively and swiftly enough to have any hope of stopping and reversing global warming we need to replace all of the special interests’ clowns and puppets by voting for people in their electorates who understand the currently escalating climate emergency and will put action to resolve the crisis as their highest priority in Parliament. Otherwise, we will have little chance to avoid the global mass extinction that will ensue if we don’t act.

Vote Climate One’s Traffic Light Voting Guide won’t tell you who to vote for, but it will help you avoid voting for anyone whose preferences are likely to flow to the COALition and their allies. Also, if you think our approach here is a useful one, please consider joining with us to become a Climate Hero.

Views expressed in this post are those of its author(s), not necessarily all Vote Climate One members.