Kathy Ann Townsend, University of the Sunshine Coast and Dominique Potvin, University of the Sunshine CoastEnvironmental scientists see flora, fauna and phenomena the rest of us rarely do. In this series, we’ve invited them to share their unique photos from the field.
When we opened a box supplied by museum curators, our research team audibly gasped. Inside was a huge Australian magpie nest from 2018.
It was more than a metre wide and made up of the strangest assortment of items, including wire coat hangers, headphones, saw blades and plastic 3D glasses — a mix of detritus reflecting our modern lifestyle.
This was one of almost 900 Australian nest specimens dating back over 195 years that we inspected for our recent, world-first study.
We estimate that today, around 30% of Australian bird nests incorporate human-made materials (primarily plastics). We also noted a steady increase in nest parasites over this period.
It’s clear the types of debris the birds use has reflected changes in society over time. They highlight the unexpected and far-reaching ways Australians impact their environment, and put birds in danger.
The first synthetic item
Birds and humans have been sharing spaces and habitats throughout history.
It’s well known birds incorporate material from their environment into their nests, making them ideal indicators of environmental changes and human activity. It’s also well known, particularly among scientists, that museum collections can provide unique insight into environmental changes through time and space.
With this in mind, our international team investigated Australian museum bird nest specimens collected between 1823 and 2018. Sourced from Museums Victoria and CSIRO’s Crace Site in Canberra, we inspected a total of 892 nests from 224 different bird species.
Australian birds generate an amazing array of nest types. Rufous fantails, for example, build delicately woven structures made of fine grass and spiderwebs, while welcome swallows and white-winged choughs create nests out of mud, which dry incredibly hard and can be used year after year.
Before the 1950s, human-made debris found in the nests consisted of degradable items such as cotton thread and paper.
This changed in 1956, when we found the first synthetic item in a bird nest from Melbourne: a piece of polyester string. This appearance correlates with the increased availability of plastic polymers across Australian society, seven years after the end of the second world war.
Australian magpies earn their name
We also determined, based on collection date and using historical maps, whether the nests came from natural, rural or urban landscapes. And it turns out the nest’s location, when it was built, and the species that made it largely determined whether human-made materials were present.
Our study found nests built close to urban areas or farmland after the 1950s by birds from the families Craticidae (Australian magpies and butcherbirds), Passeridae (old world or “true” sparrows) and Pycnonotidae (bulbuls) had significantly more human-made debris.
Familiar to many an urban bird enthusiast, these species tend to adapt quickly to new environments. The incorporation of human materials in nests is likely one example of this behavioural flexibility.
The research team also had access to ten bowerbird bowers from the family Ptilonorhynchidae, spanning more than 100 years. Male bowerbirds are known for creating elaborate structures, decorated with a range of colourful items to attract a mate.
In the 1890s, the birds decorated their bowers with natural items such as flowers and berries. Newspaper scraps were the only human-produced items we identified.
This changed dramatically 100 years later, where the most sought-after items included brightly coloured plastics, such as straws, pen lids and bottle caps.
But there are tragic consequences
When birds weave non-biodegradable materials — such as fishing line and polymer rope — into their nests, it increases the risk of entanglement, amputation and even accumulation of plastics in the gut of nestlings.
For example, we found evidence of one pallid cuckoo juvenile dying in 1981 after it was entangled in plastic twine used by its adoptive bell miner parents.
Plastic was not the only issue. We found the prevalence of nest parasites that attack the young chicks also increased by about 25% over the last 195 years.
Nest parasites can kill huge numbers of nestlings. Recent research into the forty-spotted pardalote in Tasmania, a threatened species, has shown nest parasites kill up to 81% of its nestlings.
What has caused this increase isn’t clear. However, the team determined it wasn’t directly linked to urban or rural habitat type, or the presence of human-made materials in the nest. This goes against the findings of other studies, which show a decrease of parasites in nests that incorporated items such as cigarettes.
Interestingly, we did find eucalyptus leaves might deter parasites, as nests that incorporated them were less likely to show evidence of parasitism.
It may be, therefore, that sticking with certain natural materials is not only better for the safety of nest inhabitants, but also may have an added effect of pest control.
Stop littering, please
While most are aware of how plastics harm sea life, our study is one of the first to show the impact goes further to harm animals living in our own backyard. If the trend continues, the future for Australian birds looks bleak.
However, we can all do something about it.
The team had access to nests from 224 different species, which equates to only about a quarter of Australia’s total of 830 bird species.
There is still plenty more to discover.
Salman Shooshtarian, RMIT University and Tayyab Maqsood, RMIT UniversityStrong community opposition to a proposed waste facility in regional New South Wales made headlines earlier this year. The A$3.9 million facility would occupy 2.7 hectares of Gunnedah’s industrial estate. It’s intended to process up to 250,000 tonnes a year of waste materials from Sydney.
Much of this is construction waste that can be used in road building after processing. Construction of the plant will employ 62 people and its operation will create 30 jobs. Yet every one of the 86 public submissions to the planning review objected to the project.
Residents raised various concerns, which received widespread local media coverage. They were concerned about water management, air quality, noise, the impact of hazardous waste, traffic and transport, fire safety and soil and water. For instance, a submission by a local businessman and veterinary surgeon stated:
“The proposed facility is too close to town, residences and other businesses […] Gunnedah is growing and this proposed development will be uncomfortably close to town in years to come.”
The general manager of the applicant said descriptions such as “toxic waste dump” were far from accurate.
“It’s not a dump […] Its prime focus is to reclaim, reuse and recycle.”
He added: “[At present] the majority of this stuff goes to landfill. What we’re proposing is very beneficial to the environment, which is taking these resources and putting them back into recirculation. The reality is the population is growing, more waste is going to get generated and the upside is we’re much better processing and claiming out of it than sending it to landfill.”
Why are these facilities needed?
According to the latest data in the National Waste Report 2020, Australia generated 27 million tonnes of waste (44% of all waste) from the construction and demolition (C&D) sector in 2018-19. That’s a 61% increase since 2006-07. This waste stream is the largest source of managed waste in Australia and 76% of it is recycled.
However, recycling rates and processing capacities still need to increase massively. The environmental impact statement for the Gunnedah project notes Sydney “is already facing pressure” to dispose of its growing construction waste. Most state and national policies – including the NSW Waste Avoidance and Resource Recovery Strategy 2014-2021, NSW Waste and Resource Recovery Infrastructure Strategy and 2018 National Waste Policy – highlight the need to develop infrastructure to effectively manage this waste.
Why, then, do people oppose these facilities?
Public opposition to new infrastructure in local neighbourhoods, the Not-in-My-Back-Yard (NIMBY) attitude, is a global phenomenon. Australia is no exception. We have seen previous public protests against waste facilities being established in local areas.
The academic literature reports the root causes of this resistance are stench and other air pollution, and concerns about impacts on property values and health. Factors that influence individuals’ perceptions include education level, past experience of stench and proximity to housing.
What are the other challenges of recycling?
Our research team at RMIT University explore ways to effectively manage construction and demolition waste, with a focus on developing a circular economy. Our research shows this goal depends heavily on the development of end markets for recycled products. Operators then have the confidence to invest in recycling construction and demolition waste, knowing it will produce a reasonable return.
A consistent supply of recycled material is needed too. We believe more recycling infrastructure needs to be developed all around Australia. Regional areas are the most suitable for this purpose because they have the space and a need for local job creation.
To achieve nationwide waste recycling, however, everyone must play their part. By everyone, we mean suppliers, waste producers, waste operators, governments and the community.
Today we are facing new challenges such as massive urbanisation, shortage of virgin materials, increasing greenhouse gas emissions and bans on the export of waste. These challenges warrant new solutions, which include sharing responsibility for the waste we all generate.
What can be done to resolve public concerns?
Government has a key role to play in educating the public about the many benefits of recycling construction and demolition waste. These benefits include environmental protection, more efficient resource use, reduced construction costs, and job creation.
Government must also ensure communities are adequately consulted. A local news report reflected Gunnedah residents’ concern that the recycling facility’s proponent had not contacted them. They initiated the contact. One local said:
“I do understand the short-term financial gains a development like this will bring to the community, but also know the financial and environmental burden they will cause.”
Feedback from residents triggered a series of consultation sessions involving all parties.
A robust framework for consulting the community, engaging stakeholders and providing information should be developed to accompany any such development. Community education programs should be based on research.
For instance, research indicates that, unlike municipal waste recycling facilities, construction and demolition waste management facilities have negligible to manageable impact on the environment and residents’ health and well-being. This is due to the non-combustible nature of most construction materials, such as masonrt.
Such evidence needs to be communicated effectively to change negative community attitudes towards construction and demolition waste recycling facilities. At RMIT, through our National Construction & Demolition Waste Research and Industry Portal, we continue to play our part in increasing public awareness of the benefits.
With the right tools, we can mine cities
Deepika Mathur, Charles Darwin University and Imran Muhammad, Massey UniversityInstalling solar panels is an easy way to lower your carbon footprint and cut electricity bills. But our recent research found there are many incentives to remove them prematurely, adding to Australia’s massive waste problem.
Researchers predict Australia will accumulate 1 million tonnes of solar panel waste by 2047 — the same weight as 19 Sydney Harbour Bridges.
But this number is likely to be higher, as we found people often choose to remove panels after just 10 to 12 years of use. This is much earlier than their estimated end-of-life age of 30 years (and potentially older).
Unfortunately, recycling is just a small part of the solution. So why is this happening, and what can we do about it?
Australia’s shocking ‘material footprint’
Australians have heeded the call to increase renewable energy. The installed capacity of panels across Australia has increased dramatically from 25.3 megawatts in 2007 to 77,078 megawatts in 2017. Likewise, the rooftop solar market capacity has almost doubled between 2014 and 2018.
Australia has committed to the UN Sustainable Development Goal of using fewer resources. And this requires us to use products (like solar panels) efficiently, with less waste. But Australia’s 2020 progress update shows our per capita material footprint is increasing. In fact, it’s one of the highest in the world, at 70% above the OECD average.
To help lower our growing material footprint and keep e-waste out of landfills, we need to ensure solar panels are sustainable in life, as in death.
It is assumed the primary reason why people remove solar panels is due to technical failures, such as when they’ve reached their expiry after 30 years, or breaking due to extreme weather or during transport. But failing to generate electricity doesn’t explain why many are thrown away prematurely.
So, we interviewed solar panel installers, recycling organisations, advocacy groups and local government waste managers across the Northern Territory. And our resulting qualitative research found social and economic incentives for removing solar panels.
Out with the new, in with the newer
We found a whole system of panels gets removed when only a few panels are damaged, as the new panels must have similar electrical properties to the old.
If the panels are still under warranty, the manufacturer often pays to replace the whole set, even when only a few are faulty. This means working panels are removed alongside the faulty panels, prematurely turning into waste.
Solar panels have also become a commodity item. Many of us dump old phones and cars when newer technology becomes available, and solar panels get the same treatment. After recovering the investment in solar panels through reduced electricity bills, some people are keen to get newer, more efficient models with a new warranty.
Our research also suggests government incentives aimed at rolling out more solar panels have caused consumers to replace their entire solar array. This is because previous rebates didn’t cover the replacement of only one or a few panels.
Finally, the life of solar inverters is usually 10-12 years, much shorter than the 30-year life span of the panels themselves. Some people use this as an opportunity to install a new set of solar panels when they change their inverters.
So why can’t we just recycle them?
There’s currently little research on what we can do with panels when they’re removed for reasons other than technical failure.
Researchers often put forward recycling as the preferred option for removed panels. But sending the growing number of working panels to recycling facilities is a tremendous waste of resources, and increases the burden for panel recycling, which is still in its nascent stages.
Managing waste is the responsibility of states and territories, and they align their waste strategies with the federal government’s National Waste Policy.
But there’s no directive yet at the national level on solar panel disposal, specifically. This means there’s a patchwork of policies across the states and territories for managing this waste.
Victoria, for example, has identified solar panels as the fastest growing waste stream in the state’s overall e-waste flow, and the state government has banned them from landfills.
But such measures wouldn’t work for the Northern Territory, given its lack of processing facilities and the distance to the recycling centres in southern Australia, which are at least 1,500 kilometres away. With ample open land, they’re more likely to end up dumped illegally.
What do we do?
Australia needs clear guidelines at a national level on collecting, transporting, stockpiling and disposing solar panels. A lack of clear policy hampers state, territory and local governments from managing this waste effectively.
By proposing recycling as preferred option to manage this waste, we risk excluding other important options in the waste management hierarchy, such as reducing waste in the first place by making solar panels that last, extending their life.
The federal government has also touted “product stewardship” as a potential solution. This is where those involved in producing, selling, using and disposing products share the responsibility to reduce their environmental impact.
But this model wouldn’t effectively service regional and remote areas, as collecting and transporting goods from remote locations comes at a very high financial and environmental cost.
It’s worth noting some panels do undergo a kind of “second life”. There’s a unique demand for secondhand panels from people who can’t afford new systems, those looking to live off-grid, small organisations keen to reduce energy bills, and mobile home and caravan owners.
But with a number of massive solar farms proposed across northern Australia, it’s more important than ever to explore new strategies to manage removed solar panels, with clear policies and creative solutions.
The authors gratefully acknowledge the contributions of Robin Gregory from Regional Development Australia, Northern Territory to this article.
Katherine Aigner, Australian National UniversityOn Saturday the Adelaide Festival hosted a public showing of Australian Atomic Confessions, a documentary I co-directed about the tragic and long-lasting effects of the atomic weapons testing carried out by Britain in South Australia in the 1950s.
Amid works from 20 artists reflecting on nuclear trauma as experienced by Indigenous peoples, the discussion that followed brought up the ways in which attempts at nuclear colonisation have continued in South Australia, and are continuing right now.
For the fourth time in 23 years South Australia is being targeted for a nuclear waste dump — this time at Napandee, a property near Kimba on the Eyre Peninsula.
The plan is likely to require the use of a port, most probably Whyalla, to receive reprocessed nuclear fuel waste by sea from France, the United Kingdom and the Lucas Heights reactor in NSW via Port Kembla.
The waste will be stored above ground in concrete vaults which will be filled for 100 years and monitored for a further 200-300 years.
Nuclear waste can remain hazardous for thousands of years.
The 734 locals who took part backed the proposal 61.6%
The Barngarla people are far from the first in South Australia to be excluded from a say about proposals to spread nuclear materials over their land.
It’s not the first such proposal
Australian Atomic Confessions explores the legacy of the nine British atomic bombs dropped on Maralinga and Emu Field in the 1950s, and the “minor trials” that continued into the 1960s.
After failed clean-ups by the British in the 1960s followed by a Royal Commission in the 1980s, the Australian Radiation Protection and Nuclear Safety Agency conducted a cleanup between 1995 and 2000 it assures us was successful to the point where most of the contaminated areas at Maralinga fall well within the clean-up standards applied for unrestricted land use.
But experts remain sceptical, given the near-surface burial of plutonium and contamination remaining across a wide area.
The Tjarutja people are allowed to move through and hunt at the Maralinga site with their radiation levels monitored but are not permitted to camp there permanently.
We are told that what happened in the 1950s wouldn’t happen today, in relation to the proposed nuclear waste dump. But it wasn’t our enemies who bombed us at Maralinga and Emu Field, it was an ally.
In exchange for allowing 12 British atomic bombs tests (including those at the Monte Bello Islands off the northern coast of Western Australia), the Australian government got access to nuclear technology which it used to build the Lucas Heights reactor.
It is primarily the nuclear waste produced from six decades of operations at Lucas Heights that would be dumped onto Barngarla country in South Australia, closing the links in this nuclear trauma chain.
Nuclear bombs and nuclear waste disproportionately impact Indigenous peoples, yet Australia still has not signed up to the United Nations Declaration on the Rights of Indigenous Peoples. The declaration requires states to ensure there is no storage or disposal of hazardous materials on the lands of Indigenous peoples without their free, prior and informed consent.
Nor has Australia shown any willingness to sign up to the Treaty on the Prohibition of Nuclear Weapons which came into force on January 22 this year after a lobbying campaign that began in Australia and was endorsed by Indigenous leaders worldwide.
Aboriginal people have long known the dangers of uranium on their country.
Water from the Great Artesian Basin has been extracted by the Olympic Dam copper-uranium mine for decades. Fragile mound springs of spiritual significance to the Arabunna People are disappearing, posing questions for the mining giant BHP to answer.
Australian uranium from BHP Olympic Dam and the now-closed Rio Tinto Ranger mine fuelled the 2011 Fukushima nuclear disaster.
It is likely that the radiation problems at Fukushima are, at least in part, fuelled by uranium derived from our traditional lands. This makes us feel very sad.
The Irati Wanti (The Poison, Leave It!) campaign led by a council of senior Aboriginal women helped defeat earlier proposals for nuclear waste dumps between 1998 and 2004.
There remains strong Indigenous opposition to the current nuclear waste proposal.
Over the past five years, farmers have joined with the Barngarla People to protect their communities and the health of the land.
In 2020 the government introduced into the Senate a bill that would do away with traditional owners’ and farmers’ rights to judicial reviews and procedural fairness in regard to the use of land for the facility.
Resources Minister Keith Pitt is deciding how to proceed.
Last week, Australia took an important step towards addressing the ongoing effects of the 2018 waste crisis. The federal parliament passed legislation banning the export of unprocessed waste overseas via the Recycling and Waste Reduction Act 2020.
The new law provides an impetus to reconfigure local infrastructure to reprocess and re-manufacture recyclables onshore. It should create local demand to reuse these recovered materials in infrastructure, packaging and products as part of a move towards a circular economy.
It’s encouraging to see the federal government finally providing clear policy direction for the waste industry and making Australia more responsible for how our waste is recovered. But it’s far from enough to temper the waste crisis.
Is exporting waste ‘bad’?
The total amount of waste generated in 2018-19 went up 10% from just two years earlier — and only half of that was recycled. Meanwhile, opportunities to export material for overseas recycling have been drying up.
In 2019, Australia exported an estimated 7% of all waste generated. The proportion is much higher for the household commingled recycling bin, where around one-third of all paper and plastics were exported to overseas trading partners, particularly in Asia.
Exporting material recovered from waste isn’t “bad” per se, particularly when you consider Australia imports more manufactured goods than we make locally. Currently, our economy remains structured around exporting virgin (new) and recyclable materials, which are made into products offshore and then re-imported.
So, when we export well-sorted, quality, recyclable material, it’s no different than exporting, say, iron ore.
However, just dumping “rubbish” on other countries is not acceptable. And even exporting potentially recyclable material without taking responsibility for how the material will be recovered overseas leads to a greater risk of it being dumped or burned.
Such an economic structure makes us reliant on international markets and the policy priorities of those countries.
This was highlighted in 2018 when China banned waste imports of all but the highest purity, with other countries in Asia following suit. This shocked Australia’s (and the world’s) recycling industry, and led to plummeting prices for certain waste materials and increased stockpiling and short-term landfilling.
What’s more, when developing countries import too much waste or low-quality material, their infrastructure and markets can become overwhelmed. The waste then ends up “leaking” into the environment, including the ocean, as litter.
A ban on Australia’s waste export was first announced in August 2019 to help address our responsibility for ocean plastics. The ban could localise much of Australia’s reprocessing — and possibly, manufacturing — activity.
What does the ban involve?
Effectively, the ban prohibits the export of specific raw (unprocessed) materials collected for recycling: plastic, paper, glass and tires. Any materials that have been re-processed and turned into other “value-added” materials (those ready for further use) can still be exported under the law. For example, a single type of plastic cleaned and shredded into “flakes”, or cleaned packaging glass crushed into “cullet”.
The law is accompanied by commitments from the federal and state governments to help address some of the critical systemic barriers to onshore processing, such as the lack of existing infrastructure and domestic markets for reprocessed material.
No room for error
Without sufficient transition measures, it’s possible the ban could lead to more waste ending up in landfills, stockpiling or illegal dumping.
For the ban to be effective, a lot of things need to go right. This includes:
sufficient time to plan, get approval and build the new recycling infrastructure
sufficient financing to test new technologies and build new facilities
creating local demand and markets to reuse and remanufacture recycled plastics, paper, glass and tires
Getting the transition right will be critical for Western Australia, South Australia, Queensland and the Northern Territory, which are particularly lacking in proper infrastructure.
It’s also important for NSW and Victoria because of the high proportion of banned materials they currently export. For example, over 80% of Australia’s exported plastic was from NSW and Victoria, while 90% of exported glass was from Victoria.
Given exports are only a part of overall waste material flows, it’s great to see the ban is part of a suite of responses. This includes the Recycling Modernisation Fund, and the recent $10 million National Product Stewardship Investment Fund and Product Stewardship Centre of Excellence.
Still, we shouldn’t lose sight of the fact these are predominantly “end-of-pipe” solutions.
Options include minimum design standards and extended producer responsibility, which would make manufacturers and retailers financially responsible for ensuring their products are recycled. This would incentivise better “up the chain” (design) choices.
And as a major importer of manufactured products, Australia also needs to manage what’s coming into the country through improved standards, such as minimum requirements for recyclability and durability, or prohibiting problematic materials in inferior products that will quickly become waste.
Ultimately, it’s far better for the environment to reduce the generation of waste in the first place. Together with better design, this will move us towards a more circular economy.
If Australia’s new waste and recycling law represents increasing momentum towards a circular economy in Australia, rather than a pinnacle on which we rest, it will be an excellent step forward.
Jenni Downes, Research Fellow, BehaviourWorks Australia (Monash Sustainable Development Institute), Monash University; Damien Giurco, Professor of Resource Futures, University of Technology Sydney, and Rose Read, Adjunct professor, University of Technology Sydney
How do we save whales and other marine animals from plastic in the ocean? Our new review shows reducing plastic pollution can prevent the deaths of beloved marine species. Over 700 marine species, including half of the world’s cetaceans (such as whales and dolphins), all of its sea turtles and a third of its seabirds, are known to ingest plastic.
When animals eat plastic, it can block their digestive system, causing a long, slow death from starvation. Sharp pieces of plastic can also pierce the gut wall, causing infection and sometimes death. As little as one piece of ingested plastic can kill an animal.
About eight million tonnes of plastic enters the ocean each year, so solving the problem may seem overwhelming. How do we reduce harm to whales and other marine animals from that much plastic?
Like a hospital overwhelmed with patients, we triage. By identifying the items that are deadly to the most vulnerable species, we can apply solutions that target these most deadly items.
Some plastics are deadlier than others
In 2016, experts identified four main items they considered to be most deadly to wildlife: fishing debris, plastic bags, balloons and plastic utensils.
We tested these expert predictions by assessing data from 76 published research papers incorporating 1,328 marine animals (132 cetaceans, 20 seals and sea lions, 515 sea turtles and 658 seabirds) from 80 species.
We examined which items caused the greatest number of deaths in each group, and also the “lethality” of each item (how many deaths per interaction). We found the experts got it right for three of four items.
Flexible plastics, such as plastic sheets, bags and packaging, can cause gut blockage and were responsible for the greatest number of deaths over all animal groups. These film plastics caused the most deaths in cetaceans and sea turtles. Fishing debris, such as nets, lines and tackle, caused fatalities in larger animals, particularly seals and sea lions.
Turtles and whales that eat debris can have difficulty swimming, which may increase the risk of being struck by ships or boats. In contrast, seals and sea lions don’t eat much plastic, but can die from eating fishing debris.
Balloons, ropes and rubber, meanwhile, were deadly for smaller fauna. And hard plastics caused the most deaths among seabirds. Rubber, fishing debris, metal and latex (including balloons) were the most lethal for birds, with the highest chance of causing death per recorded ingestion.
What’s the solution?
The most cost-efficient way to reduce marine megafauna deaths from plastic ingestion is to target the most lethal items and prioritise their reduction in the environment.
Targeting big plastic items is also smart, as they can break down into smaller pieces. Small debris fragments such as microplastics and fibres are a lower management priority, as they cause significantly fewer deaths to megafauna and are more difficult to manage.
Flexible film-like plastics, including plastic bags and packaging, rank among the ten most common items in marine debris surveys globally. Plastic bag bans and fees for bags have already been shown to reduce bags littered into the environment. Improving local disposal and engineering solutions to enable recycling and improve the life span of plastics may also help reduce littering.
Lost fishing gear is particularly lethal. Fisheries have high gear loss rates: 5.7% of all nets and 29% of all lines are lost annually in commercial fisheries. The introduction of minimum standards of loss-resistant or higher quality gear can reduce loss.
Other steps can help, too, including
incentivising gear repairs and port disposal of damaged nets
penalising or prohibiting high-risk fishing activities where snags or gear loss are likely
and enforcing penalties associated with dumping.
Outreach and education to recreational fishers to highlight the harmful effects of fishing gear could also have benefit.
Balloons, latex and rubber are rare in the marine environment, but are disproportionately lethal, particularly to sea turtles and seabirds. Preventing intentional balloon releases and accidental release during events and celebrations would require legislation and a shift in public will.
The combination of policy change with behaviour change campaigns are known to be the most effective at reducing coastal litter across Australia.
Reducing film-like plastics, fishing debris and latex/balloons entering the environment would likely have the best outcome in directly reducing mortality of marine megafauna.
Lauren Roman, Postdoctoral Researcher, Oceans and Atmosphere, CSIRO; Britta Denise Hardesty, Principal Research Scientist, Oceans and Atmosphere Flagship, CSIRO; Chris Wilcox, Senior Principal Research Scientist, CSIRO, and Qamar Schuyler, Research Scientist, Oceans and Atmospheres, CSIRO
It’s estimated about two million tonnes of plastics enter the oceans from rivers each year. But our waterways aren’t just conveyor belts transporting land waste to the oceans: they also capture and retain litter.
Currently, the most common method for monitoring litter relies on humans conducting on-ground visual counts. This process is labour-intensive and makes it difficult to monitor many locations simultaneously or over extended periods.
As part of CSIRO’s research to end plastic waste, we’ve been developing an efficient and scalable environmental monitoring system using artificial intelligence (AI).
The system, which is part of a larger pilot with the City of Hobart, uses AI-based image recognition to track litter in waterways.
Global insights help build a reliable model
The technology is underpinned by two branches of AI: computer vision and deep learning. Computer vision involves training computers to understand and interpret images and videos, whereas deep learning imitates how our brains process data.
Drawing on these capabilities, we worked in partnership with Microsoft (using its Azure cloud computing services) to develop an automated system for monitoring river litter.
We have been detecting and classifying items floating on the surface of Hobart’s stormwater channels, the River Thames in the UK and the Buriganga River in Bangladesh.
We’ve remotely analysed the amount of litter, the type of litter and how this changes across locations.
Major damage from food packaging and bottles
Our work relies heavily on two applications of computer vision. These are “object detection” and “image classification”.
Object detection specifies the location of a particular object in an image and assigns it a label. Image classification assigns one or more labels to the image as a whole.
Before either of these models can be applied reliably, however, they have to be trained, tested and validated using a large number of labelled images. For this, we drew from our footage of river litter collected from Hobart, London and Dhaka.
Our dataset now contains more than 6,100 images with 14,500 individual items. The items are labelled across more than 30 categories including plastic bottles, packaging, beverage cans, paper and plastic cups.
Our data revealed food packaging, beverage bottles and cups were by far the most frequently spotted litter items across all three countries.
Fake images aren’t always harmful
To build a well-performing machine learning model, we needed a balanced set of training images featuring all item categories — even if certain categories are more frequent in real life.
Introducing synthetic (computer generated) images to our dataset was a game changer.
These images were generated by Microsoft’s synthetics team based in Seattle. They rendered various objects and superimposed them over backgrounds obtained from our field photos.
Once the digital objects were created, the superimposition process was automatic. Thus, the team managed to produce thousands of synthetic pictures over just a few weeks, rapidly expanding our training dataset.
How are objects identified?
There are a few steps by which our system identifies litter objects in photos. First, the photos are all scored against a single-label (“trash”) object detector. This identifies items of litter in the frame and stores their coordinates as annotations.
These coordinates are then used to isolate the items and score them against an image classifier which includes all the litter categories.
Finally, the model presents the category it thinks the item most likely belongs to, along with a suggested probability for how accurate this guess is.
An AI-driven approach to litter management allows a quicker response than a manual system. But when it comes to litter, the major challenge lies in creating a model that can account for millions of different shapes, colours and sizes.
We wanted to build a flexible model that could be transferred to new locations and across different river settings, including smaller streams (such as Hobart’s stormwater system) and large urban rivers (such as the River Thames or the Buriganga River).
This way, rather than building new models for each location, we only have to deploy more cameras. Data retrieved could help identify litter hot spots, implement better waste-related policies and improve waste management methods to make them safer, smarter and relatively cheaper.
Keeping an eye on Hobart’s litter
We’ve also been collaborating with the City of Hobart to develop an autonomous sensor network to monitor gross pollutant traps, such as floating barriers or litter socks.
These structures, integrated into Hobart’s stormwater drainage system, are supposed to prevent solid waste such as cans, bottles, tree branches and leaves from reaching the estuary and ocean.
We currently have a network of sensors and six cameras installed under bridges tracking litter in the traps. The system can inform an operator when a trap requires emptying, or other maintenance.
Once in full use, the technology will provide almost real-time monitoring of litter around Hobart — assisting efforts to reduce environmental harm caused by stagnant, and potentially hazardous, waste lost to the environment.
Biomethane technology is no longer on the backburner in Australia after an announcement this week that gas from Sydney’s Malabar wastewater plant will be used to power up to 24,000 homes.
Biomethane, also known as renewable natural gas, is produced when bacteria break down organic material such as human waste.
The demonstration project is the first of its kind in Australia. But many may soon follow: New South Wales’ gas pipelines are reportedly close to more than 30,000 terajoules (TJs) of potential biogas, enough to supply 1.4 million homes.
Critics say the project will do little to dent Australia’s greenhouse emissions. But if deployed at scale, gas captured from wastewater can help decarbonise our gas grid and bolster energy supplies. The trial represents the chance to demonstrate an internationally proven technology on Australian soil.
What’s the project all about?
Biomethane is a clean form of biogas. Biogas is about 60% methane and 40% carbon dioxide (CO₂) and other contaminants. Turning biogas into biomethane requires technology that scrubs out the contaminants – a process called upgrading.
The resulting biomethane is 98% methane. While methane produces CO₂ when burned at the point of use, biomethane is considered “zero emissions” – it does not add to greenhouse gas emissions. This is because:
it captures methane produced from anaerobic digestion, in which microorganisms break down organic material. This methane would otherwise have been released to the atmosphere
it is used in place of fossil fuels, displacing those CO₂ emissions.
Biomethane can also produce negative emissions if the CO₂ produced from upgrading it is used in other processes, such as industry and manufacturing.
Biomethane is indistinguishable from natural gas, so can be used in existing gas infrastructure.
The Malabar project, in southeast Sydney, is a joint venture between gas infrastructure giant Jemena and utility company Sydney Water. The A$13.8 million trial is partly funded by the federal government’s Australian Renewable Energy Agency (ARENA).
Sydney Water, which runs the Malabar wastewater plant, will install gas-purifying equipment at the site. Biogas produced from sewage sludge will be cleaned and upgraded – removing contaminants such as CO₂ – then injected into Jemena’s gas pipelines.
Sydney Water will initially supply 95TJ of biomethane a year from early 2022, equivalent to the gas demand of about 13,300 homes. Production is expected to scale up to 200TJ a year.
Biomethane: the benefits and challenges for Australia
A report by the International Energy Agency earlier this year said biogas and biomethane could cover 20% of global natural gas demand while reducing greenhouse emissions.
As well as creating zero-emissions energy from wastewater, biomethane can be produced from waste created by agriculture and food production, and from methane released at landfill sites.
The industry is a potential economic opportunity for regional areas, and would generate skilled jobs in planning, engineering, operating and maintenance of biogas and biomethane plants.
Methane emitted from organic waste at facilities such as Malabar is 28 times more potent than CO₂. So using it to replace fossil-fuel natural gas is a win for the environment.
It’s also a win for Jemena, and all energy users. Many of Jemena’s gas customers, such as the City of Sydney, want to decarbonise their existing energy supplies. Some say they will stop using gas if renewable alternatives are not found. Jemena calculates losing these customers would lose it A$2.1 million each year by 2050, and ultimately, lead to higher costs for remaining customers.
The challenge for Australia will be the large scale roll out of biomethane. Historically, this phase has been a costly exercise for renewable technologies entering the market.
The global picture
Worldwide, the top biomethane-producers include Germany, the United Kingdom, Sweden, France and the United States.
The international market for biomethane is growing. Global clean energy policies, such as the European Green Deal, will help create extra demand for biomethane. The largest opportunities lie in the Asia-Pacific region, where natural gas consumption and imports have grown rapidly in recent years.
Australia is lagging behind the rest of the world on biomethane use. But more broadly, it does have a biogas sector, comprising than 240 plants associated with landfill gas power units and wastewater treatment.
In Australia, biogas is already used to produce electricity and heat. The step to grid injection is sensible, given the logistics of injecting biomethane into existing gas infrastructure works well overseas. But the industry needs government support.
Last year, a landmark report into biogas opportunities for Australia put potential production at 103 terawatt hours. This is equivalent to almost 9% of Australia’s total energy consumption, and comparable to current biogas production in Germany.
A clean way to a gas-led recovery
While the scale of the Malabar project will only reduce emissions in a small way initially, the trial will bring renewable gas into the Australia’s renewable energy family. Industry group Bioenergy Australia is now working to ensure gas standards and specifications are understood, to safeguard its smooth and safe introduction into the energy mix.
The Morrison government has been spruiking a gas-led recovery from the COVID-19 recession, which it says would make energy more affordable for families and businesses and support jobs. Using greenhouse gases produced by wastewater in Australia’s biggest city is an important – and green – first step.