‘Biodegradable’ plastic will soon be banned in Australia. That’s a big win for the environment

Jenni Downes, Monash University; Kim Borg, Monash University, and Nick Florin, University of Technology Sydney

To start dealing with Australia’s mounting plastic crisis, the federal government last week launched its first National Plastics Plan.

The plan will fight plastic on various fronts, such as banning plastic on beaches, ending polystyrene packaging for takeaway containers, and phasing in microplastic filters in washing machines. But we’re particularly pleased to see a main form of biodegradable plastic will also be phased out.

Biodegradable plastic promises a plastic that breaks down into natural components when it’s no longer wanted for its original purpose. The idea of a plastic that literally disappears once in the ocean, littered on land or in landfill is tantalising — but also (at this stage) a pipe dream.

Why ‘biodegradable’ ain’t that great

“Biodegradable” suggests an item is made from plant-based materials. But this isn’t always the case.

A major problem with “biodegradable” plastic is the lack of regulations or standards around how the term should be used. This means it could, and is, being used to refer to all manner of things, many of which aren’t great for the environment.

Many plastics labelled biodegradable are actually traditional fossil-fuel plastics that are simply degradable (as all plastic is) or even “oxo-degradable” — where chemical additives make the fossil-fuel plastic fragment into microplastics. The fragments are usually so small they’re invisible to the naked eye, but still exist in our landfills, water ways and soils.

The National Plastics Plan aims to work with industry to phase out this problematic “fragmentable” plastic by July, 2022.

Some biodegradable plastics are made from plant-based materials. But it’s often unknown what type of environment they’ll break down in and how long that would take.

Those items may end up existing for decades, if not centuries, in landfill, litter or ocean as many plant-based plastics actually don’t break down any quicker than traditional plastics. This is because not all plant-based plastics are necessarily compostable, as the way some plant-based polymers form can make them incredibly durable.

Plastic cutlery with 'biodegradable' written on it — There’s no evidence to suggest anything labelled as ‘biodegradable’ is better for the environment.
Shutterstock

So it’s best to avoid all plastic labelled as biodegradable. Even after the ban eliminates fragmentation — the worst of these — there’s still no evidence remaining types of biodegradable plastics are better for the environment.

Compostable plastics aren’t much better

Compostable plastic is another label you may have come across that’s meant to be better for the environment. It’s specifically designed to break down into natural, non-toxic components in certain conditions.

Unlike biodegradable plastics, there are certification standards for compostable plastics, so it’s important to check for one the below labels. If an item doesn’t have a certification label, there’s nothing to say it isn’t some form of mislabelled “biodegradable” plastic.

Home compost label.
Australasian Bioplastics Association (ABA)

But most certified compostable plastics are only for industrial composts, which reach very high temperatures. This means they’re unlikely to break down sufficiently in home composts. Even those certified as “home compostable” are assessed under perfect lab conditions, which aren’t easily achieved in the backyard.

And while certified compostable plastics are increasing, the number of industrial composting facilities that actually accept them isn’t yet keeping up.

Nor are collection systems to get your plastics to these facilities. The vast majority of kerbside organics recycling bins don’t currently accept compostable plastics and other packaging. This means placing compostable plastics in these bins is considered contamination.

Industrial compost label.
Australasian Bioplastics Association (ABA)

Even if you can get your certified compostable plastics to an appropriate facility, composting plastics actually reduces their economic value as they can no longer be used in packaging and products. Instead, they’re only valuable for returning nutrients to soil and, potentially, capturing a fraction of the energy used to produce them.

Finally, if you don’t have an appropriate collection system and your compostable plastic ends up in landfill, that might actually be worse than traditional plastic. Compostable plastics could release methane — a much more potent greenhouse gas than carbon dioxide — in landfill, in the same way food waste does.

So, you should only consider compostable plastics when you have a facility that will take them, and a way to get them there.

And while the National Plastics Plan and National Packaging Targets are aiming for at least 70% of plastics to be recovered by 2025 (including through composting), nothing yet has been said about how collection systems will be supported to achieve this.

Is recycling helpful?

Only an estimated 9% of plastics worldwide (and 18% in Australia) are actually recycled. The majority ends up in landfill, and can leak into our oceans and natural environments.

In Australia, systems for recycling the most common types of plastic packaging are well established and in many cases operate adequately. However, there are still major issues.

Compostable cup of coffee — Compostable plastics aren’t usually made for your backyard compost bin.
Shutterstock

For example, many plastic items can’t be recycled in our kerbside bins (including soft and flexible plastics such as bags and cling films, and small items like bottle lids, plastic cutlery and straws). Placing these items in your kerbside recycling bin can contaminate other recycling and even damage sorting machines.

What’s more, much of the plastic collected for recycling doesn’t have high value “end markets”. Only two types of plastic — PET (think water or soft drink bottles and some detergent containers) and HDPE (milk bottles, shampoo/conditioner/detergent containers) — are easily turned back into new plastic containers.

The rest end up in a stream called “mixed plastics”, much of which we have traditionally exported overseas for recycling due to low demand here. The new waste export ban may help fix this in the future.

A brief guide to help you responsibly dispose of your plastic.
University Technology Sydney, Author provided

So what do you do about plastic?

The obvious answer then, is to eliminate problematic plastic altogether, as the National Plastics Plan is attempting to do, and replace single-use plastics with reusable alternatives.

Little actions such as bringing your reusable water bottle, coffee cup and cutlery, can add up to big changes, if adequately supported by businesses and government to create a widespread culture shift. So too, could a swing away from insidious coffee capsules, cling wrap and cotton buds so many of us depend on.

Opting too, for plastic items made from recycled materials can make a big impact on the feasibility of plastic recycling.

If you do end up with plastic on your hands, take a quick glance at the graphic above, or read the University Technology Sydney’s Detailed Decision Guide to Disposing of Plastics.

Jenni Downes, Research Fellow, BehaviourWorks Australia (Monash Sustainable Development Institute), Monash University; Kim Borg, Research Fellow at BehaviourWorks Australia, Monash Sustainable Development Institute, Monash University, and Nick Florin, Research Director, Institute for Sustainable Futures, University of Technology Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Fruit bats are the only bats that can’t (and never could) use echolocation. Now we’re closer to knowing why

Camilo López-Aguirre, UNSW and Laura A. B. Wilson, Australian National University

Scientists have found another piece in the puzzle of how echolocation evolved in bats, moving closer to solving a decades-long evolutionary mystery.

All bats — apart from the fruit bats of the family Pteropodidae (also called flying foxes) — can “echolocate” by using high-pitched sounds to navigate at night.

An international study led by us, published today in Current Biology, has shown how the capability for sophisticated echolocation not only evolved multiple times in groups of bats, but also that it never evolved in fruit bats.

The remarkable sounds of bats

To navigate using echolocation, bats produce high-frequency calls in their larynx (voice box) and emit these through their nose or mouth. These calls, usually made at higher frequencies than humans can hear, echo off objects and bounce back.

From this feedback, bats can extract information about the spatial and textural properties of their surroundings.

For three decades, scientists have tried to understand how echolocation evolved in bats and why this adaptation didn’t extend to fruit bats. So far, they’ve struggled to reach a consensus.

Some evolutionary biologists think fruit bats could once echolocate like their modern counterparts, but at some point lost this capability. Others propose fruit bats never acquired this trait in the first place and that it evolved several times in different bat groups.

Embryos help unpack an evolutionary mystery

Uncovering the history of bat echolocation was always going to be a hard task. There are more than 1,400 species of bat, making up about a quarter of all mammal species on Earth. As such, they come in a remarkable range.

However, bat fossils are notably scarce and fragmented. Scientists lack the specimens needed to reconstruct the 65-million-year evolutionary history of bats.

Also, the genetic information of today’s echolocating bat species has done little to help us understand how the sonar-like system actually works.

We took a different approach. Rather than focusing on bat genes or fossils, we examined the very early development of their ear and throat bones.

Evolutionary studies have shown that if a group of species ends up losing a trait its ancestors possessed, not all aspects of the trait are completely lost. Instead, the trait often starts to develop in the very early stages of life, but doesn’t progress.

So if echolocation was present in the common ancestor of all bats, we would expect modern fruit bats to show some developmental trace of this in their ear and throat development.

Our research group, which included biologists from City University of Hong Kong, University of Tokyo and the Vietnam Academy of Science and Technology, studied hundreds of bat embryo specimens from all around the world.

We used a modern imaging method to digitally reconstruct the soft tissue structure of the embryos in microscopic detail. We compared fruit bats to echolocating bats and also non-echolocating mammals, such as mice.

Striking results

Our analysis revealed fruit bats were indistinguishable from non-echolocating mammals in all aspects of their early ear bone development.

There were also no features which were similar to those observed in bats that do have sophisticated echolocation capability. In other words, there was no evidence to suggest fruit bats would ever have been able to echolocate.

This raised several questions for us. Does this mean the common ancestor of all bats didn’t have the echolocation skills afforded to future bats? This is a possibility.

Alternatively, this common ancestor might have only had a very primitive version of echolocation. If so, it may have looked and sounded strikingly different to what we see in today’s sophisticated echolocators.

Unfortunately, we can’t know for sure which is correct. Pteropodids have the most incomplete fossil record of all bat lineages, so we can’t study how their ear bones changed over time.

Confirming previous theories

Our team also discovered the two major groups of sophisticated bat echolocators, Rhinolophoidea and Yangochiroptera, have different patterns of ear and throat development to one another. This suggests they evolved their sonar independently.

This conclusion also fits in with the latest insights from bat genome sequencing, which indicate that if the ancestor of all bats did echolocate, this was likely some kind of primitive echolocation — not the deft laryngeal echolocation found in modern bats.

The next step will be to combine insights from developmental analysis with bat genomic data.

By studying how the hearing-related genes of bats are expressed during early development, we could find out whether fruit bats completely erased a primitive echolocation system present in an ancestor, or whether it was ever there at all.

Camilo López-Aguirre, PhD Candidate, UNSW and Laura A. B. Wilson, Senior Lecturer, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Fires bring home climate-driven urgency of rethinking where we live – and how

Barbara Norman, University of Canberra; Peter Newman, Curtin University, and Will Steffen, Australian National University

As we were still recovering from last summer’s fires in southeast Australia, the southwest fires brought in 2021. Both were far more intense fires than seen before, driven by deep drying, extreme heat and powerful winds. It’s a harsh reminder that climate change is going to bounce us up and down with increased frequency.

We have published a new research paper in the journal Nature, titled Apocalypse Now: Australian Bushfires and the Future of Urban Settlements. It was put together as the fires were raging in the east, and comes out as Perth residents are still reeling from the devastating fires in the west this month.

Both sides of Australia have now learnt hard lessons.

What have we learned?

1. Bushfires have become more frequent and more intense

The 2019-2020 Black Summer bushfires were unprecedented in their scale and were fuelled by unprecedented climatic conditions.

The fires burned about 21% of eastern Australia’s temperate broad-leafed (mainly eucalypt) forests. That’s more than ten times the annual average of about 2%, even in extreme fire seasons.

Individual fires were also massive in size. For example, the Gospers Mountain fire near Sydney burned more than 500,000 hectares. This made it the largest individual fire ever recorded in Australia.

2. Climate change is creating unprecedented conditions

The preceding climatic conditions were also unprecedented. 2019 was Australia’s hottest year on record. The average maximum temperature was 2.09°C above the baseline and 0.5°C higher than the previous record.

Australia also experienced its driest year on record in 2019. Rainfall was about 40% below average across the continent.

Climate change played a strong role in driving these weather records.

3. It’s a global problem

Modelling by the Intergovernmental Panel on Climate Change (IPCC) shows if the world goes past the 2°C rise on average and moves towards 3°C, the world is likely to lose most of the forests in dry climate areas like ours.

The southwestern region of Australia has been drying for 40 years, linked to climate change. In recent years, the Perth region has depended on desalinating seawater for about half of the water supply to more than 2 million residents.

perth desalination plant — Perth’s rainfall has fallen dramatically for decades and the city now relies very heavily on desalination for its water supply.
Callistemon/Wikimedia Commons, CC BY-SA

The bushfires have become more intense over the past decade. Similar patterns are found in California and other areas with a Mediterranean climate.

4. The global community is watching

State and federal governments must commit to net-zero emissions targets. These would signal to industry and communities that there is a diminishing future for fossil fuels and encourage investment in a renewable future.

The fires strikingly remind people that we remain a global climate laggard. This will soon spread to our trade discussions and ability to raise finance for nation-building infrastructure and major projects.

5. Our settlements will need to change

The most vulnerable parts of our cities are in the urban fringes where there is substantial scattered development set in bush. Such homes are going to be increasingly vulnerable. As a result, owners will find insurance harder to secure.

Consolidating the city will need to start by reviewing such lifestyle zonings to reduce risk to communities. Rural areas and coastal settlements also will need a new model based on new green technology infrastructure, new building materials and new ways of living together rather than living in forest hideaways.

6. Indigenous fire management needs to be applied to all bush

Indigenous fire techniques are beginning to be developed and adapted with local communities after the fires last summer. These are needed around our cities and in urban bushland, as well as in forests and rangelands across our country.

If we don’t begin to adopt such “cool burn” approaches, then we face the prospect of losing our forests, even those in and around our cities.

What must we do to make this happen?

Key elements include:

regional urban centres make the transition to renewable energy
urban design becomes responsive to climate through retrofitting programs and consolidating settlements
settlements retreat from areas of high climate risk, working with affected communities to identify options
community climate action plans get funded, including climate change adaption, climate-sensitive urban design and heat reduction though urban green spaces
embed action on climate change (mitigation and adaptation) through a national investment program, in partnership with the states, to review urban planning processes.

This is a crisis that needs strong leadership of the type shown in the COVID response. That means working together, fostering innovation and investing in creating and building more climate-adapted communities.

This article is part of a series The Conversation is running on the nexus between disaster, disadvantage and resilience. You can read the rest of the series here.

Barbara Norman, Chair of Urban & Regional Planning and Director of Canberra Urban & Regional Futures, University of Canberra; Peter Newman, Professor of Sustainability, Curtin University, and Will Steffen, Emeritus Professor, Fenner School of Environment & Society, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Renewables need land – and lots of it. That poses tricky questions for regional Australia

Bonnie McBain, University of Newcastle

Renewable energy capacity in Australia is expected to double, or even triple, over the next 20 years. There is one oft-overlooked question in this transition: where will it all be built?

Many renewable energy technologies need extensive land area. Wind turbines, for instance, cannot be located too close together, or they won’t work efficiently.

Some land will be in urban areas. But in the transition to 100% renewable energy, land in the regions will also be needed. This presents big challenges, and opportunities, for the farming sector.

Two important factors lie at the heart of a smooth transition. First, we must recognise that building renewable energy infrastructure in rural landscapes is a complex social undertaking. And second, we must plan to ensure renewables are built where they’ll perform best.

Aerial view of solar farm — Australia’s renewable energy expansion will require plenty of space – most of it in the regions.
Shutterstock

Bringing renewables to the regions

My research has examined how much land future energy generation will require, and the best way to locate a 100% renewable electricity sector in Australia.

A National Farmers Federation paper released last week called for a greater policy focus on renewable energy in regional Australia. It said so-called renewable energy zones should “be at the centre of any regionalisation agenda” and that this would give the technology a competitive advantage.

Hosting renewable energy infrastructure gives farmers a second income stream. This can diversify a farming business and help it withstand periods of financial pressure such as drought. An influx of new infrastructure also boosts regional economies.

But successfully integrating renewables into the agricultural landscape is not without challenges.

A wicked problem

Renewable energy enjoys widespread public support. However its development can lead to social conflicts. For example, opposition to wind wind farms, often concentrated at the local level, can be motivated by concerns about:

perceived health impacts
changes to the landscape
damage to wildlife
loss of amenity
reduced property values
procedural fairness.

A proposed A$2 billion wind energy development on Tasmania’s King Island shows the difficulties involved in winning community support. The project was eventually scrapped in 2014, for economic reasons.

Research showed how despite the proponents TasWind using a “best practice” mode of community engagement, the proposal caused much social conflict. For example, the holding of a vote served to further polarise the community, and locals were concerned that the community consultation process was not impartial.

The local context was also significant: the recent closure of an abattoir, and associated job losses, had increased the community’s stress and sense of vulnerability. This led some to frame the new proposal as an attempt by a large corporation to capitalise on the island’s misfortune.

The King Island experience has all the hallmarks of a “wicked problem” – one that is highly complex and hard to resolve. Such problems are common in policy areas such as land-use planning and environmental protection.

People protest against wind farm proposal — Achieving community consensus on wind farm developments can be challenging.
Daniel Mariuz/AAP

Wicked problems typically involve competing perspectives and interests. Often, there is no single, correct solution that works for everyone. For example at King Island, the abattoir closure did not mean all locals considered the wind energy proposal to be the answer.

When seeking to address complex policy problems, such as building renewable energy in regional areas, the best approach involves:

collaboration between all affected parties, including people beyond the property where the infrastructure will be located
relationship-building between all those involved, to allow each to see the other’s perspective
shared decision-making on whether the infrastructure will be built, and where.

Competition for land is intensifying around the world, especially as the population grows. High consumption levels in the West require ever-more land for resources such as food, and land degradation is rife.

To help alleviate this pressure, renewable energy developments may need to co-exist with other land uses, such as cattle grazing around wind turbines. And in many cases, renewable energy should not be built on the most productive cropping land.

Cows graze in front of wind turbines — Cattle grazing and wind turbines can co-exist.
Mick Tsikas/AAP

Recipe for success

A successful energy transition will require strategic, long-term planning to determine where renewable generation is best located.

Our research indicates that while many places in Australia have renewable energy potential, some are far better than others. Wind energy is usually best located near the coast, solar farms in arid inland regions and rooftop solar power in densely-populated eastern Australia.

Traditionally, Australia’s electricity grid infrastructure, such as high-voltage transmission lines, has been located around coal-fired generators and large population centres. Locating renewables near this infrastructure might make it cheaper to connect to the grid. But those sites may not be particularly windy or sunny.

Australia’s electricity grid should be upgraded and expanded to ensure renewables generators are located where they can perform best. Such strategic planning is just what the National Farmers Federation is asking for. Improved connectivity will also help make electricity supplies more reliable, allowing electricity to be transferred between regions if needed.

Making renewables do-able

The economic and environmental benefits of renewable energy are well known. But without social acceptance by communities hosting the infrastructure, the clean energy transition will be slowed. There is more work to be done to ensure new renewables projects better respond to the needs of regional communities.

And to ensure Australia best fulfils its renewable energy potential, electricity grid technology must be upgraded and expanded. To date, such planning has not featured prominently enough in public conversation and government policy.

If Australia can overcome these two tricky problems, it will be well on the way to ensuring more reliable electricity, the best return on investment and a low-carbon energy sector.

Bonnie McBain, Lecturer, University of Newcastle

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Kevin's Walk on the Wild Side

Environment, Wildlife and Wilderness – Articles and News

Daily Archives for March 13, 2021

‘Biodegradable’ plastic will soon be banned in Australia. That’s a big win for the environment

Why ‘biodegradable’ ain’t that great

Compostable plastics aren’t much better

Is recycling helpful?

So what do you do about plastic?

Fruit bats are the only bats that can’t (and never could) use echolocation. Now we’re closer to knowing why

The remarkable sounds of bats

Embryos help unpack an evolutionary mystery

Striking results

Confirming previous theories

Fires bring home climate-driven urgency of rethinking where we live – and how

What have we learned?

What must we do to make this happen?

Renewables need land – and lots of it. That poses tricky questions for regional Australia

Bringing renewables to the regions

A wicked problem

Recipe for success

Making renewables do-able

Why ‘biodegradable’ ain’t that great

Compostable plastics aren’t much better

Is recycling helpful?

So what do you do about plastic?

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The remarkable sounds of bats

Embryos help unpack an evolutionary mystery

Striking results

Confirming previous theories

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What have we learned?

What must we do to make this happen?

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Bringing renewables to the regions

A wicked problem

Recipe for success

Making renewables do-able

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