I’ve always wondered: are water crystals bad for the environment?



Gardeners use water crystals to drought-proof their plants.
Shutterstock

Michelle Ryan, Western Sydney University

This is an article from I’ve Always Wondered, a series where readers send in questions they’d like an expert to answer. Send your question to alwayswondered@theconversation.edu.au


Are water crystals bad for the environment? –Terry Gilmour

This is an excellent question, and something an environmentally conscious gardener might wonder. With changing rainfall patterns, drought and an increasing average temperature in Australia many people are looking for ways to save water in their garden, and adding water crystals to your soil appears to be a good solution. But what do we really know about water crystals and are they bad for the environment?

Well, you can put your mind at ease: water crystals are not bad for the environment. In fact, in other forms they are actually used to help protect the environment.

What are water crystals?

Water crystals are tiny super-absorbent polymers (a long chain that’s made up of identical repeating molecules), about the size of a sugar crystal. They are added to potting mix or added to soil in a garden bed to increase the water holding capacity of the soil.

Water crystals act like a sponge, binding water molecules with the molecule chains in the crystals (with what’s technically known as cross-link bonding). This makes the crystal swell, creating a three-dimensional gel network up to 300 times its original size, absorbing water and nutrients.




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Over 5-6 years water crystals slowly degrade, releasing the absorbed water into the root zone of the plant and wetting the soil.

While many water crystals are marketed as water-saving, and many people use them to drought-proof their plants, it’s really important to know that these water crystals don’t actually conserve water. The plants still use the same amount of water, but instead of the water flowing through to the bottom of the pot and into the saucer and evaporating, or through to the bottom of the garden bed, the water crystals hold onto the water in the root zone of the plant. It makes for a more efficient use of the water in the soil.

Gardeners are not always able to frequently water their plants on hot summer days.
Shutterstock

Cross-linked vs linear polymers

To understand where the environmental concerns come from, we have to get a little technical.

The most common type of water crystal on the market is a cross-linked polyacrylamide. Cross-linked polyacrylamides are water absorbent but not water soluble. One of their best-known uses is in disposable nappies.

The environmental concern regarding water crystals comes from people confusing these cross-linked polyacrylamides with non-cross-linked polyacrylamide used by industry. While they are commonly described in the same way, they have a different chemical bonding and properties.




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Non-cross-linked (linear) polyacrylamide is water-soluble. It is currently used in Australian agriculture for improving soil and to help control erosion. It also plays an integral role in aiding flocculation as part of the sewage treatment process.

A 1997 study found when non-cross linked polyacrylamide degrades it creates acrylamide, a suspected carcinogen and neurotoxin.

Obviously this would be very concerning if it also affected water crystals! Acrylamide could leach into the soil and water and be taken up by plants, entering the human food chain. However there’s no proof cross-linked polyacrylamides – which are the water crystals you’d find in a gardening store – behave like this.

It is not clear if water crystals have a negative impact on Australia’s rivers and streams.
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It is also worth noting that further studies, including one published in 2008, found a very small amount (less than 0.5 parts per billion) of acrylamide was released into the environment, which does not cause any environmental concern.

You may also worry water crystals could impact aquatic life if they found their way into rivers and streams. The good news is there’s no reported toxicity or impact on aquatic life from commercially available water crystals (results are more mixed for the water soluble non-cross-linked polyacrylamide, with some studies finding little impact and others showing no toxicity.




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The other good news is water crystals do not accumulate in the soil or water over the long term. The use of water crystals has no adverse impact on soil microbe populations, which we need for a good healthy soil. If used as directed there is no risk to human health (however, it is always good practice to wear gloves while handling any chemical product).

So environmentally conscious gardeners don’t need to worry about water crystals. They’re great for people who don’t have time to water their pot plants every day in summer. Remember, these crystals do not save water but increase the water holding capacity of the soil, so you still need to water your plants regularly – especially on hot days!The Conversation

Michelle Ryan, Lecturer – Environmental Health and Management, Western Sydney University

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

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Why Australia needs to kill cats


John Read, University of Adelaide and Katherine Moseby, UNSW

Introduced cats are a key threat to 123 of Australia’s threatened species.

The management of cats is challenging and divisive; many options such as rehoming, trap-neuter-release and euthanasia have been used around the world with varying success.

Australia’s recent commitment to killing 2 million feral cats to protect its native wildlife has attracted international attention and some have considered the project harsh.

While the actual target of 2 million has been rightly criticised as arbitrary and more based on public relations than rigorous science, it’s true non-lethal methods are not enough to stem the environmental havoc cats cause. Particularly in light of a UN report highlighting the world’s extinction crisis, Australia urgently needs well-targeted cat culls.




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Non-lethal methods

A range of effective non-lethal methods are already protecting wildlife from cats. Cat-exclusion fences have collectively improved the conservation status of many threatened species. In addition, an increasing number of Australian councils have created progressive cat management bylaws designed to protect pet cats, wildlife and humans from the effects of free-ranging cats.

The centrepiece of many of these bylaws, supported by the vast majority of animal welfare groups, is the containment of pet cats on their owner’s property. Indoor cats live longer, safer lives than cats that are allowed to roam.

Stray cats are harder to manage. These are the cats that do not have a home, but may be directly or indirectly fed by people.




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Because they are unowned, no-one is officially accountable for their health or welfare. Groups of like-minded individuals feed and even provide veterinary assistance to some of these cats, further blurring the distinction between pet and feral cats.

A trend promoted by “no kill” shelters and advocacy groups in some US states and Europe is for clowders (groups) of stray cats to be desexed, vaccinated and released back onto the streets. This process is called trap-neuter-release (TNR).

A recent RSPCA best-practice cat management discussion paper proposed a trial of TNR in Australia too – but there are very good reasons why this would be counterproductive for cat welfare.

The risks of releasing unowned cats

Informed animal welfare advocate groups, including PETA, strongly condemn the release of unowned cats, neutered or otherwise, due to the welfare risks to these cats. Human health professionals and wildlife advocates also oppose maintaining groups of cats.

Dense outdoor cat clowders are hotbeds of toxoplasmosis infections. This cat-borne disease is increasingly being linked to a range of chronic mental health conditions including schizophrenia and Alzheimer’s disease.

“No kill” groups that promote TNR erroneously claim that neutered cats significantly reduce the breeding potential of erroneously named cat “colonies”, in the same way that release of neutered mosquitoes is a proven technique for controlling disease-bearing mosquitoes.

One of us (John) has recently written a book on protecting wildlife and cats that suggests five fatal biological flaws in this logic:

  1. Neutering mosquitoes works because impotent individuals “swamp” short-lived wild insect populations that mate only once. By contrast, female cats typically mate repeatedly when on heat, so an encounter with a neutered tom is of little consequence.

  2. Unlike lions, domestic cats evolved as solitary hunters. While domestic cats can tolerate living in high-density clowders, they do not form hierarchical colonies, packs or prides where alpha individuals restrict the feeding, breeding or survival of subordinate animals.

  3. Although loud cat fights might make you assume males fight over the right to exclusively mate with a female, most litters of outdoor cats are sired by multiple males. Even supposedly “dominant” males seldom intervene when another male courts a female. Neutered male cats will not protect females in their clowder from non-desexed interlopers. This means that more than 90% of cats need to be neutered to restrict population increases, an incredibly challenging proposition.

  4. Despite the misleading label “colony”, cat clowders are not closed populations. Rather, cats typically move around to take advantage of abundant food resources. And unwanted pets are often dumped at clowder sites. The failures of several well-studied TNR programs are attributed to cats migrating or being dumped at these sites.

  5. Despite needing repeated vaccinations to protect them from debilitating diseases, few stray cats can be captured a second time. And many can never be captured at all. This leaves them and their clowder effectively unmanageable.

TNR is biologically flawed, cruel to cats – because it returns them to a hazardous environment – and ineffective when not accompanied by high levels of adoption.

Harming marine ecosystems

Not only do predatory cats harm native wildlife, but stray or feral clowders can also directly influence marine ecosystems and fisheries.

Many commercial cat foods contain increasingly threatened predatory fish that are high in the food chain and hence use more nutrients and biological energy than plants or herbivores. US dogs and cats consume one-third of the animal-derived protein eaten by humans, with accompanying greenhouse gas emissions.

The cat food provided to stray clowders adds to this biological expense. In 2009 alone, the US-based Best Friends Animal Society, one of the major promoters of TNR, distributed over 80,000 tonnes of cat food to unowned cats. There are no similar studies in Australia, and we appear to have far lower rates of stray-cat-feeding, but it is still part of the ecological impact of stray cats.

Even more insidiously, seals, otters and dolphins in oceans around the world die from cat-borne diseases spread mainly from clowders.




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Humane euthanasia

Fortunately, both science and animal welfare standards are consistent about management of cats. All healthy domestic cats for which safe homes can be found should be adopted or rehomed, then kept indoors following neutering and vaccination. All other cats, including ferals and strays that cannot be rehomed quickly, should be humanely euthanased.

Feeding or releasing cats (neutered or otherwise) threatens our wildlife and perpetuates the cycle of suffering, disease, predation and social annoyance. Non-lethal options such as feral cat-proof fencing can still be part of the solution, but euthanasia remains an important part of controlling feral and stray cats to protect our native wildlife.


Among the Pigeons: Why our cats belong indoors (2019) by John Read is published by Wakefield Press.The Conversation

John Read, Associate Lecturer, Ecology and Environmental Sciences, University of Adelaide and Katherine Moseby, Research fellow, UNSW

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

Why Adani’s finch plan was rejected, and what comes next



The black-throated finch is on the verge of extinction.
Brian McCauley/flickr, CC BY-NC

Samantha Hepburn, Deakin University and April Reside, The University of Queensland

Adani’s plan to manage an endangered finch was rejected last week by the Queensland government, stalling progress on the Carmichael mine.

The mine would cover much of the best remaining habitat for the endangered black-throated finch. The Queensland government required Adani to commit to gathering more accurate finch population data, limit the cattle grazing in the finch conservation area and determine food availability throughout the year, before they could approve the plan.

The rejection is one of two outstanding environmental approvals required before Adani can commence work on the mine. The second is the plan to manage groundwater-dependent ecosystems, which the Queensland government has yet to come to a decision on.




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The federal government has been reported as “already approving” the finch plan. But legally, the Queensland government must determine whether the plan complies with the conditions of the environmental authority and, under the bilateral framework, the federal government must give due regard to this assessment.

What’s wrong with Adani’s plan?

Last Friday Queensland’s Department of Environment and Science decided not to approve Adani’s black-throated finch management plan because it does not fulfil certain basic requirements.

The decision is based on a detailed report from an independent expert panel.

The black-throated finch is on the verge of extinction, one of 238 threatened Australian birds.

The black-throated finch is experiencing habitat loss and degradation.
Steve Dew/flickr, CC BY



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The greatest threat to the black-throated finch is habitat loss: it has disappeared from over 80% of its original range. Strong protection, and careful management, of its remaining habitat is crucial.

The finch, once found across north-eastern Australia, is now largely found on Moray Downs and surrounding properties, north-west of Clermont in central Queensland. A core part of the habitat is within the 28,000 hectare (ha) footprint of the Carmichael mine, where there are far more black finches than elsewhere due to the intact woodlands and a history of minimal livestock grazing.

It is expected the mines will disturb 50,977 ha of black-throated finch habitat, and that 34,156 ha will be completely cleared.

A total of 87 square kilometres of habitat will be destroyed through the creation of open pits, and a further 61 square kilometres may be degraded beyond repair due to the influence of underground mining on groundwater.

After habitat loss, the second greatest threat to the finch is cattle grazing, which destroys the grass seeds they need to survive. Yet Adani’s management plan for the black-throated finch involved grazing cattle on areas that are supposed to be devoted to conservation of the finch.

Instead of establishing a finch conservation reserve, the Adani plan proposed what was in effect a paddock. Providing a species management plan that effectively conserves finch habitat is a core condition of Adani’s mining licence.

State vs federal priorities

The Queensland government’s rejection of the plan brings into stark focus some of the problems with the existing environmental assessment framework.

The Adani plan includes cattle grazing, despite the threat to finch habitats.
Shutterstock

The environmental authority for the mining licence was approved by the Federal government. The environmental management plan for the finch did not, however, address core impact concerns. And yet this is the very reason that the plan was required from the outset. The inadequacies of the plan only became apparent because of the oversight of the Queensland government.

The federal government has not been proactive despite’s its mandate under our National environment act – the Environmental Protection Biodiversity Conservation act. In fact, a recent analysis found the federal government has approved hundreds of projects to clear black-throated finch habitat over the last 18 years.




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There are clearly differences in priorities regarding the environment between a federal Liberal and a state Labor government. However, environmental assessment can only be effective if is not undermined by political agendas, and is grounded in scientific rigour and scrutiny.

A one-stop shop

At the federal level, any project likely to have a “significant impact” on a matter protected by the Environment Protection and Biodiversity Conservation Act must be referred to the federal environment minister.

If the minister decides the project impacts a matter of national environmental significance, he or she will then determine how to assess that project at the national level. Legislated options include: an environmental impact statement, a public environment report and public inquiry.

The federal government has entered into bilateral agreements with all state and territory governments. As a result, rather than the state and federal governments conducting separate assessment, the aim is to promote a single, focused environmental evaluation.

The Queensland government has entered into a bilateral assessment agreement with the Commonwealth government for Adani’s coal project, which effectively allows it to make an environmental assessment that the Commonwealth Minister will then take account of when deciding whether to grant approval.

This means that both the Queensland and the federal government are involved in the approval and assessment process environmental authorities and conditions, one of those being the management plan for the black-throated finch. In order to optimise outcomes they need to work together collaboratively.

Where to next?

The rejection means that Adani will now need to submit a new or revised plan that addresses the Queensland government’s concerns. In particular, Adani will need to limit cattle grazing in the conservation area, and gather more information regarding the availability of seed throughout the year.

This may take time but is critical, because in its current form, the plan does not meet the legal requirements for the Environmental Authority, which means that it cannot be approved at the state level.

Without state approval the Adani coal mine cannot proceed. The Queensland government has rigorously assessed Adani’s management plan by commissioning a report by an independent expert panel and then acting on the advice of this report.

This robust approach is crucial to the whole framework of environmental assessment. Genuine commitment to protecting endangered species and managing vital groundwater resources is vital if we want to reverse Australia’s dire trajectory of environmental decline.The Conversation

Samantha Hepburn, Director of the Centre for Energy and Natural Resources Law, Deakin Law School, Deakin University and April Reside, Researcher, Centre for Biodiversity and Conservation Science, The University of Queensland

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

The tasty, weed-like desert raisin plant is as big as a carpark



The desert raisin is a member of Australia’s native bush tomato family.
Mark Marathon/Wikimedia, CC BY

Dr Angela Pattison, University of Sydney

Sign up to the Beating Around the Bush newsletter here, and suggest a plant we should cover at batb@theconversation.edu.au.


The species Solanum centrale, also known as kutjera in several Aboriginal languages, or the desert raisin in English, stands out in Australia’s wild bush tomato family in more ways than one.

A typical desert raisin plant in the wild looks fairly unimpressive from the surface, and certainly a lot less striking than the photos which pop up in an internet search.

In fact, if you don’t know what you are looking for, you may miss them. They are fairly scrawny with greeny-grey hairy leaves and grow no taller than to the bottom of your shin.

You might only spot a shoot every few metres between other shrubs. Each shoot only has a handful of leaves, and it typically carries three to 10 sultana-sized fruit. Like sultanas, they’re unappealingly brown and shrivelled. And you’ll only see them if they have escaped hungry desert fauna.

But its humble appearance belies its significance to both people and the environment.

The fruit from this plant has been a staple in desert communities for thousands of years. It resembles a raisin but tastes like a piquant or smoky sun-dried tomato, and because it dries on the plant it has a long storage life relative to other fruit.




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Its cultural significance and ability to grow in sandy arid areas where almost no other domesticated plants survive makes this species a prime target for an enterprise based in remote Aboriginal communities, producing a unique fruit with plenty of health benefits to consumers.



The Conversation

What makes the desert raisin unique?

Iceberg-like growth

Like an iceberg which is much bigger under the surface than appears from above, the desert raisin plant is much bigger under the surface of the ground than it appears. A single plant in the wild can span dozens of metres through hardy underground connections. The largest confirmed single plant was about one quarter of a hectare – but who knows how big these plants can really grow?

It expands in multiple directions from the seed plant over successive rains via roots which grow roughly parallel to the surface, producing new shoots as it expands.

Root sprouting allows a plant to grow a new shoot many metres away from the previous shoot while avoiding a vulnerable seedling stage. This feature is common among many unrelated desert plant families.

For example, a single Populus euphratica tree in the hyper-arid Taklamakan Desert of China was found to produce clonal shoots over an area of 121ha.

Unabated resilience

Desert raisins are known to grow vigorously following a disturbance, either natural or man-made. It is quite common, for instance, when driving through Australia’s arid interior to find piles of sand beside freshly graded roads covered in bush tomato shoots after rain.




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This is because a grader, a tool that smooths the surface of a road, cuts dormant roots and throws them, mixed with sand, onto the side of the road. The roots are ready to re-sprout as soon as they get wet.

And its not only chopping roots that appears to stimulate growth – targeted fires, fruit collection by Indigenous groups and grazing by desert marsupials have all been known to increase the vigour of patches of wild bush tomatoes over the long term.

The traditional custodians of this country knew how to manage this species for sustainable production, and people from Aboriginal nations which span the large range of edible bush tomato species have passed this knowledge down for centuries.

Cultivation

Do the unique root properties of the desert raisin remind you of a weed?

Well, yes.

When cultivated, desert raisin plants are large and thick, sometimes as high as the knee, with dozens of flowers per plant.
Wikimedia, CC BY

Other root sprouters in the Solanum family from temperate areas are vigourous weeds in cropping regions around the world.

Colonies are very difficult to eradicate as the viability of roots is not affected by cultivation and most herbicides. In fact, cultivation stimulates sprouting from root fragments.

So how does this influence the way this species can be used as a food crop?




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There are currently several cultivated stands in regional and remote Australia, and the benefits of growing the species are becoming clearer, particularly for Aboriginal communities.

With water and nutrition in their natural habitats, bush tomatoes can become incredibly productive. When cultivated, the plants are large and thick, sometimes as high as the knee, with dozens of flowers per plant. But over the seasons they respond less to water and fertiliser.

It is at this point that perhaps a disturbance can be used to stimulate production from underground lateral roots – although if they pop up in the space between beds, it can create havoc for other operations!

It is no wonder that a plant, which normally hides its massive size so it can persist in harsh conditions, becomes a showy, vigorous plant when given the same kind of treatment as horticultural plants.




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One final note. Much of the knowledge on how bush tomato and other food plants native to this country work is held by the traditional custodians of the species, the Aboriginal people.

We must all learn from Aboriginal and Torres Strait Islander people, listen, and work together so the amazing fruits of this land return to their place in human diets and landscapes, including the mighty desert raisin.


Sign up to Beating Around the Bush, a series that profiles native plants: part gardening column, part dispatches from country, entirely Australian.The Conversation

Dr Angela Pattison, Research scientist at Plant Breeding Institute, University of Sydney, University of Sydney

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

Sit! Seek! Fly! Scientists train dogs to sniff out endangered insects


Julia Mynott, La Trobe University

Three very good dogs – named Bayar, Judd and Sasha – have sniffed out the endangered Alpine Stonefly, one of the smallest animals a dog has been trained to successfully detect in its natural habitat.

The conservation of threatened species is frequently hampered by the lack of relevant data on their distributions. This is particularly true for insects, where the difficulty of garnering simple information means the threatened status of many species remains unrecognised and unmanaged.




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In alpine areas there is a pressing need for innovative methods to better reveal the distribution and abundance of threatened insects.

Alpine regions rely on cool temperatures, and since climate change will bring warmer weather and lower rainfalls, insects like the Alpine Stonefly, which lives in the alpine freshwater system, will struggle to survive.

And while insects might not be appealing to everyone, they are extremely important for ecosystem function.

Traditional survey detection methods are often labour intensive, and hard-to-find species provide limited information. This is where the labrador, border collie and samoyed came to the rescue.

La Trobe’s Anthrozoology Research Group Dog Lab in Bendigo, Victoria have been training a pool of local community volunteers and their dogs in conservation detection to use with environmental DNA sampling. Using both environmental DNA and detection dogs has the potential to generate a lot of meaningful data on these threatened stoneflies.

For seven weeks in a special program, dogs were trained to memorise the odour of the Alpine Stonefly (Thaumatoperla alpina), a threatened but iconic insect in the high plains.

The dogs have previously been trained to sniff out animal nests or faeces but not an animal itself, so this was a new approach and an Australian first.

Stoneflies are hard to catch

The Alpine Stonefly are brightly coloured aquatic insects and are difficult to find, especially as larvae in water where they live as predators for up to two years in the streams on the Bogong High Plains, Mount Buller-Mount Stirling, Mt Baw Baw and the Yarra Ranges.

They often burrow underneath cobbles, boulders and into the stream bed while the adults only emerge from the water for a few months between January and April to reproduce.

With all this in mind, it’s easy to understand why traditional detection methods can be time consuming and often ineffective.

We predominately focused on the endangered Alpine Stonefly, found across the Bogong High Plains. Their restricted distribution and habitat made them an ideal candidate to trial detection dogs and environmental DNA techniques.




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How dogs and environmental DNA help

We collected water samples from across the Bogong High Plains, Mount Buller and Mount Stirling with trace DNA, such as cells shed from the insect. The ability to quickly take these samples from a broad area to indicate the presence of a species is important to understand distribution. But this approach limits the amount of ecological information that is gathered.

Initial training introduced the dogs to the odour of the Alpine Stonefly in a controlled laboratory setting. Then they graduated from the laboratory to small areas of bushland to search for the insect.

Once the dogs successfully completed their training, it was time to trial the dogs in the alpine environment and survey Alpine Stoneflies in their natural environment.

The trial was conducted at Falls Creek with the dogs’ three volunteer handlers. And the surveys were successful, with all three dogs finding Alpine Stoneflies in their natural habitats.

So could this success be transferred to a similar species?

Absolutely. In preliminary trials, Bayar, Judd and Sasha detected the Stirling Stonefly, a related species of Thaumatoperla that lives in Mount Buller and Mount Stirling, suggesting detection dogs can transfer their conservation training from one species to another.

This is a great find as it means this technique can be used to survey yet another species of Thaumatoperla that lives in Mt Baw Baw and the Yarra Ranges.




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Our research is showing that these new sampling techniques supporting conservation are an important part of keeping biodiversity protected in alpine regions.

Now that we’ve successfully trained three dogs, we’re hoping to secure funding to conduct future and more thorough surveys on the Alpine and Stirling Stonefly, and eventually on the third species of stonefly.

By developing creative techniques to detect these species, we boost our ability to document them and, importantly, to protect them.The Conversation

Julia Mynott, Research Officer, Centre for Freshwater Ecosystems, La Trobe University

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

UK becomes first country to declare a ‘climate emergency’



Days of protest by Extinction Rebellion have brought parts of London to a standstill.
Shutterstock

Chris Turney, UNSW

On Wednesday night a bipartisan UK Parliament passed an extraordinary measure: a national declaration of an Environment and Climate Emergency.

The UK is the first national government to declare such an emergency. The decision marks a renewed sense of urgency in tackling climate change, following a visit to Parliament by teenage activist Greta Thunberg , the broadcast of David Attenborough’s documentary Climate Change: The Facts and 11 days of protest by environmental group Extinction Rebellion that paralysed parts of London.




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There are now some 49 million people living under national, city and local declarations of a climate emergency around the world.

Extinction Rebellion protesters surround a boat blocking Oxford Circus, London.
Kevin J. Frost/Shutterstock

What is a climate emergency?

While there is no precise definition of what constitutes action to meet such an emergency, the move has been likened to putting the country on a “war footing”, with climate and the environment at the very centre of all government policy, rather than being on the fringe of political decisions.

The UK are legally committed to a 80% reduction in carbon emissions by 2050 (relative to their 1990 levels) and was recently recognised as one of just 18 developed economies that have driven down carbon dioxide emissions over the last decade.

Some city and local councils have set out their climate emergency policies to become carbon zero by 2030 built around renewable energy supplies, more energy-efficient housing and a host of other measures. Yesterday’s decision in Parliament implies further national reductions and investment in this space.




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Counting down to 2030

The year 2030 is an important target. In spite of what climate contrarians might voice very loudly, five of our planet’s warmest years on record have occurred since 2010, whilst 2018 experienced all manner of climate extremes that broke numerous global records.

It’s sobering to realise that, because the oceans are a major sink of heat, the estimated 40-year delay in the release of this energy back into the atmosphere means the conditions of the last decade are in part a consequence of our pollution from the 1970s.

With the planet to experience further warming from the heat held by the oceans, there is increasing international focus on meeting the United Nation’s Paris Agreement which was signed by 197 countries in 2016. This ground-breaking agreement has the ambitious global aim of preventing global temperatures from reaching 2˚C above pre-industrial levels (the late nineteenth century) by 2100, and ideally should be no more than 1.5˚C.

Declaring an emergency was one of the demands from the Extinction Rebellion protest put to the UK government.
Shutterstock

A report by the Intergovernmental Panel on Climate Change (the IPCC) has suggested that meeting this target means annual global carbon emissions must effectively halve between now and 2030, and then fall to zero by 2050. This is a target the UK opposition party Labour are now calling for.

More recent studies suggest even more ambitious cuts may be required.

The cost of inaction

Research in Australia has investigated the cost to the global economy if the Paris Agreement is not met and the world hits 4˚C warmer.

The values are eye-watering: an estimated US$23 trillion a year over the long-term. This has been likened to the world experiencing four to six global financial crises on the scale of 2008 every year.

In Australia, the cost would be on the order of A$159 billion a year, with most of the losses caused by drought-driven collapses in agricultural productivity and sea level rise. The expense to each Australian household has been put at the order of A$14,000.

The declaration of climate emergency by the UK comes at a crucial time in Australia, just two weeks out from a federal election. While the major parties have made public statements of support for the Paris Agreement, it remains unclear whether current and former leaders are fully aware of their obligations.




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At a time when politicians discuss the need to “live within our means” when it comes to national finances, this does not appear to translate to the environment when we’re considering future generations.

Instead we seem to be caught in a debate surrounding the costs of action rather than inaction. The next generation of Australian voters certainly don’t seem confident about political commitments to their future as they hold their third national school strike tomorrow.

The welcome announcement from the UK is a major step in the right direction and potentially a watershed moment for a more sustainable global future. Is it too much to hope Australia could follow next?The Conversation

Chris Turney, Professor of Earth Science and Climate Change, ARC Centre of Excellence for Australian Biodiversity and Heritage, UNSW

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