Headline To Remember

 

The Guardian, 30 December 2023

Scientists call ‘Code Blue emergency’ for Australian oceans, as off-the-scale marine heat looms

 

OCEAN
IMAGE: AdobeStock_207088658

Climate Council, media release, 9 November 2023:

Scientists call ‘Code Blue emergency’ for Aussie oceans, as off-the-scale marine heat looms

AUSTRALIA’S OCEANS ARE in crisis, as extreme heat punishes marine life and raises the spectre of irreversible changes with profound consequences for all life on our planet, a new report has found.

The Climate Council’s CodeBlue: Oceans in Crisis report reveals the immense amount of climate-change induced heat currently being absorbed by the world’s oceans is equivalent to boiling the Sydney Harbour every eight minutes.

In addition, the Climate Council ran a highly targeted survey of 30 leading ocean scientists across five continents. All (100%) were ‘extremely’ or ‘very’ concerned about climate-driven changes to the world’s oceans. Half (53%) said these changes were outpacing scientific predictions.

Overwhelmingly, these scientists agreed ‘rapidly phasing out fossil fuels’ is the single most important action governments could take to address ocean warming.

Report author and the Climate Council’s Research Director Dr Simon Bradshaw said: "The science can’t be any clearer: our oceans are in deep trouble. Today the ocean is absorbing excess heat energy that’s equivalent to five Hiroshima bomb explosions every second, or enough to boil Sydney Harbour every eight minutes. [my yellow highlighting]

"As our climate changes, driven by rampant burning of coal, oil and gas, our seas are transforming before our eyes. More frequent and severe marine heatwaves are pushing coral reefs to the brink, ice sheets are melting at an alarming rate, ocean currents are slowing and seas are rising. The climate crisis is also an ocean crisis.

"In hospital emergency rooms, a code blue is called when a very serious life-threatening event is underway. We are calling a code blue for our oceans today, because this threatens all the species that inhabit them, the people who depend on them, as well as all life on land.

"Over the past few decades as the climate has warmed, the oceans have done an incredible job of protecting us by absorbing CO2 and an immense amount of heat, but there’s a limit to what they can take and we are close to crossing dangerous tipping points. We must scale up the use of clean energy like solar and wind, backed by storage, as quickly as we can so the use of coal, oil and gas is phased out. Every step that cuts pollution will help secure our future."

Ocean scientist Professor Gretta Pecl, Director for the Centre for Marine Socioecology at the University of Tasmania, author of the Australian ocean section of the latest IPCC report and report co-author added: “Make no mistake, ocean scientists around the world are growing increasingly concerned about rapid and intensifying changes to our oceans.

"While much of the worry for the brutal summer ahead is quite rightly about the impact on our iconic Great Barrier Reef, the scientific community is also extremely concerned about the Great Southern Reef. With forecasts of unprecedented and 'off the charts' marine heat this summer, these critical marine ecosystems face risk of utter devastation.

"We’re observing the transformation of the oceans in real time, as marine species move to survive. In Australia, at least 200 marine species have shifted since 2003, with the vast majority headed south. As waters warm further south, many will have nowhere left to go.

"While climate change has already caused extensive change to our oceans - and we’ll continue to see devastating impacts for decades - stronger action by governments to reign in fossil fuels right now can limit future harms and ensure more species and ecosystems are given a fighting chance. Scientists agree: the single most important action we can take now is to leave fossil fuels in the polluting past - and it has to happen this decade."

Pro-surfer Adrian ‘Ace’ Buchan, Surfing Australia Deputy Chairman, has joined the Climate Council’s call to declare a Code Blue emergency, adding: “Surfers have a deep and spiritual connection to the ocean and we are deeply concerned about the devastating impact the climate crisis is having on our big blue playground. Erosion is threatening our most iconic surfing spots. Our water is being polluted from flood runoff and dangerous jellyfish moving south. Loss of coral reefs and impacts on sandbars, is not just altering where and how waves break, but is also having devastating impacts on marine life.

"This is all terrible news for the millions of ocean loving Aussies - every one of whom should be concerned and take note. This is a call to action: we must work to draw attention to the ocean’s plight and push for decisive and rapid climate action now."

Tishiko King, a proud Kulkalaig woman from Masig in Zenadth Kes (Torres Strait Islands) marine scientist and co-author of the report said: “We know what is needed to protect our futures: leaving fossil fuels in the ground, having the resources to adapt to our changing climate and ocean, being able to access funds to address loss and damage.

"We have the opportunity to work together: First Nations, Pacific Island nations, non-Indigenous Australians. It starts by listening, and understanding what we all have in common. The ocean is what connects us all together."

ENDS

The Climate Council is Australia’s leading community-funded climate change communications organisation. It was founded through community donations in 2013, immediately after the then-Abbott Government dismantled the Climate Commission. We provide authoritative, expert and evidence-based advice on climate change to journalists, policymakers, and the wider Australian community. For further information, go to: climatecouncil.org.au Or follow us on social media: facebook.com/climatecouncil and twitter.com/climatecouncil

Full report can be found at:

https://www.climatecouncil.org.au/resources/code-blue-our-oceans-in-crisis/

Global ocean heat is intensifying and seas below the 30th Parallel South appear to have seen the largest increase in absorbed & accumulated heat

 

‘The world ocean, in 2023, is now the hottest ever recorded, and sea levels are rising because heat causes water to expand and ice to melt,’...‘Ecosystems are also experiencing unprecedented heat stress, and the frequency and intensity of extreme weather events are changing rapidly, and the costs are enormous.’ [Scientia Professor Matthew England, co-author of the study from the UNSW Centre for Marine Science and Innovation, in the Echo, 6 November 2023]

Over the years science has made the general public increasingly aware that anthropomorphic global warming and subsequent climate change has been heating the world's oceans beyond their normal temperature range.

What we aren't always aware of is exactly which oceans are exhibiting the most persistent warming and the fastest temperature rises.

This recent study below highlights those particular oceans.

It seems that ocean waters from the 30th Parallel south (latitude: -30° 00' 0.00" S longitude: 0° 00' 0.00") are experiencing the most rapid increase in temperatures.

To place that in perspective. From a line running through Australian waters from a point roughly halfway between Red Rock on the Clarence Coast and Corindi Beach on the Coffs Coast (NSW), right down to Tasmania and on towards Antarctica, seawater is heating and expanding until at latest measurement the reading over time now stands at 75.3 ± 4.

While from around Cape Leeuwin to Antarctica the reading is 43.2 ± 4.4.

On the Australian west coast the 30th Parallel can be thought of as running on a latitude approximately halfway between Leeman and Green Head (WA).

This study appears to indicate that, sooner rather than later, the considerable impacts of climate change will increase for the Australian population.

Nature Communications, Article number: 6888 (2023), 28 October 2023, excerpts:

Recentacceleration in global ocean heat accumulation by mode andintermediate waters

Authors: Zhi Li, Matthew H. England & Sjoerd Groeskamp

The ocean directly impacts the Earth’s climate by absorbing and redistributing large amounts of heat, freshwater, and carbon, and by exchanging these properties with the atmosphere1. About 91% of the excess heat trapped by greenhouse gases and 31% of human emissions of carbon dioxide2 are stored in the ocean, shielding humans from even more rapid changes in climate. However, warmer oceans result in sea-level rise, ice-shelf melt, intensified storms, tropical cyclones, and marine heatwaves, as well as more severe marine species and ecosystem damage. These effects depend on the pattern of ocean warming; it is thus critical to quantify the dynamics and distribution of ocean warming to better understand its consequences and predict its implications.

The observed distribution of ocean warming is not uniform. About 90% of total ocean warming is found in the upper 2000 m, with over two-thirds concentrated in the upper 700 since the 1950s, and an increase of warming rates at both intermediate depths of 700–2000 m, and in the deeper ocean below 2000 m. The Southern Ocean south of 30°S has been estimated to account for 35–43% of global ocean warming from 1970 to 2017, and an even greater proportion in recent years, while Northern Hemisphere ocean warming appears to be concentrated in the Atlantic Ocean. Due to the accumulated excess heat in ocean basins, an acceleration of total ocean warming has become more evident from recent observational-based studies. While much past work has focused on the distribution of ocean warming as a function of depth and basin, relatively little analysis has been undertaken of the distribution as a function of water-mass layers and within specific water masses. This is the focus of the present study......

When evaluating the ocean heat uptake for each decade (“Methods”), analysis of the past three decades reveals that the ocean heat uptake during 2010–2020 has increased more than 25% relative to 2000–2010 and has nearly doubled relative to the 1990’s WOCE era, as seen in Fig. 1b, where we highlight the decadal ocean heat uptake since the 1960s. Note that there has been both increased ocean sampling and a shift of the observational network from a ship-based system to the Argo network since the initiation of the global Argo array (2001–2003)34. This may impact the estimated increase in global ocean warming over the past three decades (Fig. 1). However, the rate of global mean sea-level rise has also been increasing since 1993 based on an independent estimate from satellite altimeter data1,35, providing confidence in our results given that half of the global sea surface height increase is due to thermal expansion of the ocean since altimeter measurements began. Significant ocean warming and accelerating OHC changes are also consistent with the increase in net radiative energy absorbed by Earth detected in satellite observations, something that is likely to continue throughout the 21st century in the absence of substantial greenhouse gas emissions reductions.

The increased ocean warming is non-uniformly distributed across ocean basins. Overall, in each ocean basin, an increase in OHC is observed (values indicated in Fig. 2a, b), with stronger warming in the mid-latitude Atlantic Ocean and the Southern Ocean compared with other basins. Total warming in the Southern Ocean is estimated to account for ~31% of the global upper 2000-m OHC increase from 1980–2000 to 2000–2010 (Fig. 2a), and almost half of the global OHC increase from 2000–2010 to 2010–2020 (values indicated in parentheses of Fig. 2b). Hence the Southern Ocean has seen the largest increase in heat storage over the past two decades, holding almost the same excess anthropogenic heat as the Atlantic, Pacific, and Indian Oceans north of 30°S combined (Fig. 2d). The most striking warming in the Southern Ocean is concentrated on the northern flank of the Antarctic Circumpolar Current, the location of deep mixed layers and subduction hotspots for Subantarctic Mode Water and Antarctic Intermediate Water, as well as the location of subtropical mode waters formation further equatorward (Fig. 3). The well-ventilated regions near western boundary current extensions in the North Atlantic and North Pacific also reveal large warming over the past two decades. These hotspots of ocean warming are likely linked to enhanced uptake, subduction, and lateral spreading of heat associated with mode and intermediate waters that warrant further investigation.

Fig. 2: Regional intensification in ocean warming over the past two decades, 0–2000 m. Click on image to enlarge

The ensemble mean of ocean heat content (OHC) changes averaged for years a 2000–2010 and b 2010–2020, relative to the 1980–2000 mean. Units of shadings in panels (a, b) are shown as 109 J m−2. The values over each basin indicate the OHC increase relative to the 1980–2000 mean over the Southern (S.O., south of 30°S, dark-red line), Atlantic (ATL), Pacific (PAC), and Indian (IND) Oceans, and are limited to 65°S–65°N. Units are shown as 1021. The values in parentheses in panel (b) indicate the basin-integrated OHC increase from 2000–2010 to 2010–2020. The basin mask used to distinguish ocean basins of the Southern, Atlantic, Pacific, and Indian Oceans is obtained from ref.  Superimposed gray contours represent the positions of wintertime isopycnals 25, 26.45, 27.05, and 27.5 kg m−3 at 10 m depth from SIO RG-Argo. c, d Zonally integrated OHC change (1021 per degree latitude) versus latitude for the period 2000–2010 (blue line), and 2010–2020 (red line), relative to the 1980–2000 mean. Lines in panels (c) and (d) represent the ensemble mean, and shadings indicate the ±2 ensemble standard deviation uncertainty range (±2σ) of OHC changes.

[my yellow highlighting in the excerpts]

The full study can be read and downloaded at:

https://www.nature.com/articles/s41467-023-42468-z#ref-CR13

This next Southern Hemisphere Summer may bring more unwelcome news for Australia's coastal zone

 

“Climate breakdown has begun”

[U.N. Secretary-General Antonio Guterres, 6 September 2023]

NOAA Research, Global ocean roiled by marine heatwaves, with more on the way, 28 June 2023, excerpts:

This map depicts predicted marine heatwave conditions in September 2023 as generated by the Physical Sciences Laboratory’s experimental forecast model.

Credit: NOAA Physical Sciences Laboratory. *Click on image to enlarge*

The experimental forecast, which tracks the NOAA Climate Prediction Center’s official outlook, is based on a large ensemble of climate model predictions spanning June 2023 through May 2024….

A marine heatwave is defined as a monthly regional sea surface temperature anomaly that ranks in the top 10% of warmest months compared with the 1991–2020 average. Long-term ocean warming trends also contribute to unusually high ocean temperatures, but even with the effects of long-term warming removed, models predict 25% of the global ocean will experience sharp upward departures from more recent conditions by September…..

In this scenario it appears that the Southern Ocean waters are within a probability range of between 60-80 per cent for the occurrence of marine heatwave which might have also lead to a rise in Antarctic sea surface temperatures.

Which begs the questions:

How will the over 60km long Halloween Crack in west Antarctica react to any additional stressors on the Brunt Ice Shelf?

Will the East Coast Ice Sheet which is said to contain four fifths of the world’s ice again lose ice shelf through iceberg calving as it did with C-37 (144 sq.km) & C-38 (415 sq. km) in March 2022?

Just how big are these Anthropocene Age icebergs going to grow – given many are the size of cities already? and

How long does the Southern Hemisphere have before sea level rise beyond the Antarctic Circle increases exponentially past millimetres into metres?

BACKGROUND

NASA Earth Observatory, retrieved from website 7 September 2023:

Antarctica’sBrunt Ice Shelf Finally Breaks

January 24, 2023

In February 2019, a rift spanning most of the Brunt Ice Shelf in Antarctica appeared ready to spawn an iceberg about twice the size of New York City. The question among scientists was not if the growing rift would finish traversing the shelf and break, but when? Now, nearly four years later, it has done just that.

According to the British Antarctic Survey (BAS), the break occurred late on January 22, 2023, and produced a new iceberg with an area of 1550 square kilometers (about 600 square miles). The U.S. National Ice Center has named it Iceberg A-81. The berg is visible in this image, acquired on January 24, 2023, with the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite.

The glacial ice in the shelf flows away from the interior of Antarctica and floats on the eastern Weddell Sea. (For reference, the Antarctic Peninsula and its ice shelves are located on the opposite side of the Weddell.) The shelf has long been home to the British Antarctic Survey’s Halley Research Station, where scientists study Earth, atmospheric, and space weather processes. BAS reported that the station, which was relocated farther inland in 2016 as the chasm widened, was unaffected by the recent break.

January 12, 2021

The break occurred along a rift known as Chasm 1. This chasm started growing in the 1970s, followed by a period of dormancy, and then resumed growth in 2012. It continued to lengthen for almost a decade, extending by as much as 4 kilometers (2.5 miles) per year in early 2019. But even this growth spurt slowed. That is, until the 2022–2023 Antarctic summer when the chasm sped up and ultimately broke past the McDonald Ice Rumples—a submerged knob of bedrock that served as a pinning point for this part of the shelf. Several factors may have contributed to the completion of the break, including a lack of sea ice to help resist, or “push back,” against the stresses on the shelf ice in 2023.

The second image, acquired with the Operational Land Imager (OLI) on Landsat 8, shows the extent of Chasm 1 on January 12, 2021, about two years prior to the break. Notice several other cracks across the northeast part of the shelf. The “new crack” in that image ultimately separated in February 2021 and formed Iceberg A-74.

“The rapid formation of subsequent rifts—to long-standing Chasm 1 and 2—and recent calving to the northeast makes it clear that these shelf areas are dynamic with poorly understood stresses,” said Christopher Shuman, a University of Maryland, Baltimore County, glaciologist based at NASA’s Goddard Space Flight Center.

The breaking (calving) of icebergs from ice shelves is part of a natural, cyclical process of growth and decay at the limits of Earth’s ice sheets. As glacial ice flows from land and spreads out over the sea, shelf areas farthest from shore grow thinner. These areas are stressed by storms and tides and thin as they are melted from above or below, ultimately making them more prone to forming rifts and breaking away.

As for the “new” Brunt, it remains to be seen how the complex floating glacial ice responds to the most recent calving event. According to Shuman: “We have no solid idea what ‘normal’ really is for this unusual ice shelf.”

NASA Earth Observatory images by Lauren Dauphin, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview and Landsat data from the U.S. Geological Survey. Story by Kathryn Hansen.

~~~~~~~~~~~~~~~~~

Other large iceberg calvings

NASA Earth Observatory

Early on July 12, 2017, satellites captured imagery of the new, massive iceberg that broke away from Larsen C—an ice shelf on the east side of the Antarctic Peninsula…..On July 13, the U.S. National Ice Center issued a press release confirming the new iceberg and officially naming it A-68.

February 22 - March 21, 2022

Collapse of the ice shelf in front of both the Glenzer Glacier (C-37) and Conger Glacier (C.38)commencing around 12 March 2022.

The people of the Northern Rivers, wider New South Wales and the rest of Australia have been warned that the hands of the climate crisis clock are at 30 seconds to midnight, but it's business as usual

 

Australian climate scientist Dr. Joëlle Gergis, ANU Fenner School of Environment and Society and a lead author on the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report, has recently written: 

“The climate disasters unfolding in the northern hemisphere are a sign of what’s in store here, as governments fail to act on the unfolding emergency…..

...the possibility that the Earth might have already breached some kind of global “tipping point”. The term refers to what happens when a system crosses into a different state and stays there for a very long time, sometimes even permanently. We know that once critical thresholds in the Earth system are passed, even small changes can lead to a cascade of significantly larger transformations in other major components of the system. Key indicators of regional tipping points include dieback of major ecological communities….” [my yellow highlighting]

Such observations give pause for thought.

However, the elected Mayor of the third tier governing body for the Clarence Valley Local Government Area (LGA), Cr. Ian Tiley, is apparently comfortable with the idea of personally failing to act when it comes to any proposed phasing out of logging native forests in public hands within this LGA.

At least that is the impression he gives during a photo opportunity with representatives of the state government-dominated NSW logging industry.

Presumably Mayor Tiley is willing to ignore the fact that in 2021 & again in 2022 Australian university researchers warned that logging is not just increasing the risk of severe fires, but also the risk to human lives and safety.

Logging increases the probability of canopy damage by five to 20 per cent and leads to long-term elevated risk of higher severity fires, including canopy fires. Canopy fires are considered the most extreme form of fire behaviour and can be virtually impossible to control. 

It has also been known for the last two decades that intact tree canopies can buffer against rising and increasingly record air/land temperatures due to the thermal insulation of forest canopies which protects biodiversity, allowing native flora and fauna to survive climate change-induced heat extremes better than those living on open land.

Even the NSW Dept. of Infrastructure, Planning and Natural Resources in Land Condition in the Clarence River Catchment: Report 1 - when addressing forestry as a land use - admitted back in 2014 that:

Management of forested areas for bushfire control purposes can threaten adjacent areas, cause habitat loss and encourage erosion. Public debate on this issue has been centred around the in-situ environmental impacts of the process but smoke drift over nearby population centres and the post burning effects on water quality after erosion events also impacts water supply for urban and industrial purposes. [my yellow highlighting]

Commercial logging activity occurs within the Clarence River catchment area and logged state forests do catch fire - as evidenced by Ellis State Forest near Dundurrabin south of Grafton during the 2019-20 bushfire season.

Like many other communities in the Northern Rivers region during the 2019-20 bushfire season, communities in the Clarence Valley can attest to the physical difficulties of living for days and sometimes weeks under smoke palls loaded with gases and particulate matter (including PM2.5) with a potential to affect the health.

According to the Dept. of Health's Bushfire smoke and health: Summary of the current evidence, 6 August 2020:

The Global Burden of Disease Study has shown that outdoor PM2.5 is the most important environmental risk factor in Australia, responsible for 1.6 percent of the total burden of disease in 2017. 

Evidence shows that the likelihood of an individual experiencing health effects as a result of exposure to PM2.5 depends on a number of factors. These include: the concentration of PM2.5 in air, the duration of exposure; the person’s age and whether a person has existing medical conditions (particularly cardiorespiratory disease or asthma).

It is also acknowledged that while this document focusses on the evidence relating to the physical effects that may occur as a result of bushfires smoke, bushfires have much broader mental health and societal impacts.

Clarence Valley Independent, 30 August 2023:

*click on image to enlarge*

“The Mayor also expressed his personal view, describing the timber industry as vital to the Clarence Valley.” 

I wonder if  Mr. Tiley will still be of that opinion over the next high-risk seven to seventeen years......

Quotes of the Week

“The ultimate drivers of the Anthropocene if they continue unabated through this century, may well threaten the viability of contemporary civilization and perhaps even the future existence of Homo sapiens.” [Will Steffen, et al., “The Anthropocene: Conceptual and Historical Perspectives”, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 13 March 2011]

“Massive floods, fires and heatwaves are sending us a clear message. On our present trajectory, we risk heading into a collapse of our globalised civilisation and a precipitous drop in human population — put simply, hell on earth. But we can avoid this disastrous future if we change the way we think, live our lives and interact with the rest of the living world.” [Climate scientist, the late ANU Emeritus Professor Will Steffen, quoted by Deanna “Violet” Coco, MSN, 6 December 2022]