Emissions of methane – a greenhouse gas far more potent than carbon dioxide – are rising dangerously



Sukree Sukplang/Reuters

Pep Canadell, CSIRO; Ann Stavert; Ben Poulter, NASA; Marielle Saunois, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) – Université Paris-Saclay ; Paul Krummel, CSIRO, and Rob Jackson, Stanford University

Fossil fuels and agriculture are driving a dangerous acceleration in methane emissions, at a rate consistent with a 3-4℃ rise in global temperatures this century.

Our two papers published today provide a troubling report card on the global methane budget, and explore what it means for achieving the Paris Agreement target of limiting warming to well below 2℃.

Methane concentration in the atmosphere reached 1,875 parts per billion at the end of 2019 – more than two and a half times higher than pre-industrial levels.

Once emitted, methane stays in the atmosphere for about nine years – a far shorter period than carbon dioxide. However its global warming potential is 86 times higher than carbon dioxide when averaged over 20 years and 28 times higher over 100 years.

In Australia, methane emissions from fossil fuels are rising due to expansion of the natural gas industry, while agriculture emissions are falling.

Agriculture and fossil fuels are driving the rise in methane emissions.
EPA

Balancing the global methane budget

We produced a methane “budget” in which we tracked both methane sources and sinks. Methane sources include human activities such as agriculture and burning fossil fuels, as well as natural sources such as wetlands. Sinks refer to the destruction of methane in the atmosphere and soils.

Our data show methane emissions grew almost 10% from the decade of 2000-2006 to the most recent year of the study, 2017.




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Atmospheric methane is increasing by around 12 parts per billion each year – a rate consistent with a scenario modelled by the Intergovernmental Panel on Climate Change under which Earth warms by 3-4℃ by 2100.

From 2008-2017, 60% of methane emissions were man-made. These include, in order of contribution:

  • agriculture and waste, particularly emissions from ruminant animals (livestock), manure, landfills, and rice farming
  • the production and use of fossil fuels, mainly from the oil and gas industry, followed by coal mining
  • biomass burning, from wood burning for heating, bushfires and burning biofuels.
2000 years of atmospheric methane concentrations. Observations taken from ice cores and atmosphere. Source: BoM/CSIRO/AAD.

The remaining emissions (40%) come from natural sources. In order of contribution, these include:

  • wetlands, mostly in tropical regions and cold parts of the planet such as Siberia and Canada
  • lakes and rivers
  • natural geological sources on land and oceans such as gas–oil seeps and mud volcanoes
  • smaller sources such as tiny termites in the savannas of Africa and Australia.

So what about the sinks? Some 90% of methane is ultimately destroyed, or oxidised, in the lower atmosphere when it reacts with hydroxyl radicals. The rest is destroyed in the higher atmosphere and in soils.

Increasing methane concentrations in the atmosphere could, in part, be due to a decreasing rate of methane destruction as well as rising emissions. However, our findings don’t suggest this is the case.

Measurements show that methane is accumulating in the atmosphere because human activity is producing it at a much faster rate than it’s being destroyed.

NASA video showing sources of global methane.

Source of the problem

The biggest contributors to the methane increase were regions at tropical latitudes, such as Brazil, South Asia and Southeast Asia, followed by those at the northern-mid latitude such as the US, Europe and China.

In Australia, agriculture is the biggest source of methane. Livestock are the predominant cause of emissions in this sector, which have declined slowly over time.

The fossil fuel industry is the next biggest contributor in Australia. Over the past six years, methane emissions from this sector have increased due to expansion of the natural gas industry, and associated “fugitive” emissions – those that escape or are released during gas production and transport.




Read more:
Intensive farming is eating up the Australian continent – but there’s another way


Tropical emissions were dominated by increases in the agriculture and waste sector, whereas northern-mid latitude emissions came mostly from burning fossil fuels. When comparing global emissions in 2000-2006 to those in 2017, both agriculture and fossil fuels use contributed equally to the emissions growth.

Since 2000, coal mining has contributed most to rising methane emissions from the fossil fuel sector. But the natural gas industry’s rapid growth means its contribution is growing.

Some scientists fear global warming will cause carbon-rich permafrost (ground in the Arctic that is frozen year-round) to thaw, releasing large amounts of methane.

But in the northern high latitudes, we found no increase in methane emissions between the last two decades. There are several possible explanations for this. Improved ground, aerial and satellite surveys are needed to ensure emissions in this vast region are not being missed.

More surveys are needed into thawing permafrost in the high northern latitudes.
Pikist

Fixing our methane leaks

Around the world, considerable research and development efforts are seeking ways to reduce methane emissions. Methods to remove methane from the atmosphere are also being explored.

Europe shows what’s possible. There, our research shows methane emissions have declined over the past two decades – largely due to agriculture and waste policies which led to better managing of livestock, manure and landfill.

Livestock produce methane as part of their digestive process. Feed additives and supplements can reduce these emissions from ruminant livestock. There is also research taking place into selective breeding for low emissions livestock.




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The extraction, processing and transport of fossil fuels contributes to substantial methane emissions. But “super-emitters” – oil and gas sites that release a large volume of methane – contribute disproportionately to the problem.

This skewed distribution presents opportunities. Technology is available that would enable super-emitters to significantly reduce emissions in a very cost effective way.

Clearly, current upward trends in methane emissions are incompatible with meeting the goals of the Paris climate agreement. But methane’s short lifetime in the atmosphere means any action taken today would bring results in just nine years. That provides a huge opportunity for rapid climate change mitigation.The Conversation

Pep Canadell, Chief research scientist, CSIRO Oceans and Atmosphere; and Executive Director, Global Carbon Project, CSIRO; Ann Stavert, Project Scientist; Ben Poulter, Research scientist, NASA; Marielle Saunois, Enseignant-chercheur, Laboratoire des sciences du climat et de l’environnement (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) – Université Paris-Saclay ; Paul Krummel, Research Group Leader, CSIRO, and Rob Jackson, Chair, Department of Earth System Science, and Chair of the Global Carbon Project, globalcarbonproject.org, Stanford University

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

Climate explained: what if we took all farm animals off the land and planted crops and trees instead?



Kira Volkov/Shutterstock

Sebastian Leuzinger, Auckland University of Technology


CC BY-ND

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz


I would like to know how much difference we could make to our commitment under the Paris Agreement and our total greenhouse gas emissions if we removed all cows and sheep from the country and grew plants in their place (hemp, wheat, oats etc). Surely we could easily become carbon neutral if we removed all livestock? How much more oxygen would be produced from plants growing instead? How would this offset our emissions? And what if we returned the land the animals were on to native forests or even pine plantations?

This is an interesting question and gives me the opportunity for some nice – albeit partly unrealistic – model calculations. Before I start, just two comments regarding the question itself.

Oxygen concentrations have been relatively stable at around 21% of the air we breathe for millions of years. This will not change markedly even if carbon dioxide emissions increase for years to come. Carbon dioxide concentrations, even in the most pessimistic emissions scenarios, will only get to around 0.1% of the atmosphere, hardly affecting the air’s oxygen content.

Secondly, grazing animals like cows and sheep emit methane — and that’s what harms the climate, not the grassland itself. Hemp or wheat plantations would have a similar capacity to take up carbon dioxide as grassland. But growing trees is what makes the difference.




Read more:
Climate explained: how different crops or trees help strip carbon dioxide from the air


Here’s a back-of-the-envelope calculation to work out how New Zealand’s carbon balance would change if all livestock were removed and all agricultural land converted to forest.

If New Zealand stopped farming cows and sheep, it would remove methane emissions.
Heath Johnson/Shutterstock

Converting pasture to trees

This would remove all methane emissions from grazing animals (about 40 megatonnes of carbon dioxide equivalent per year).

New Zealand has about 10 million hectares of grassland. Let us assume that mature native bush or mature pine forests store the equivalent of roughly 1,000 tonnes of carbon dioxide per hectare.

If it takes 250 years to grow mature native forests on all former agricultural land, this would lock away 10 billion tonnes of carbon dioxide within that time span, offsetting our carbon dioxide emissions (energy, waste and other smaller sources) during the 250 years of regrowth. Because pine forest grows faster, we would overcompensate for our emissions until the forest matures (allow 50 years for this), creating a net carbon sink.

Note these calculations are based on extremely crude assumptions, such as linear growth, absence of fire and other disturbances, constant emissions (our population will increase, and so will emissions), ignorance of soil processes, and many more.

If agricultural land was used to grow crops, we would save the 40 megatonnes of carbon dioxide equivalent emitted by livestock in the form of methane, but we would not store a substantial amount of carbon per hectare.




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Steps towards a carbon-neutral New Zealand

How should we interpret this rough estimate? First, we must acknowledge even with our best intentions, we still need to eat, and converting all agricultural land to forest would leave us importing food from overseas — certainly not great for the global carbon budget.

Second, it shows if livestock numbers were at least reduced, and we all turned to a more plant-based diet, we could reduce our emissions substantially. The effect would be similar to reforesting large parts of the country.

Third, this example also shows that eventually, be it after 250 years in the case of growing native forests, or after about 50 years in the case of pine forests, our net carbon emissions would be positive again. As the forests mature, carbon stores are gradually replenished and our emissions would no longer be compensated. Mature forests eventually become carbon neutral.

Even though the above calculations are coarse, this shows that a realistic (and quick) way to a carbon-neutral New Zealand will likely involve three steps: reduction of emissions (both in the agricultural and energy sectors), reforestation (both native bush and fast growing exotics), and a move to a more plant-based diet.The Conversation

Sebastian Leuzinger, Professor, Auckland University of Technology

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

Intensive farming is eating up the Australian continent – but there’s another way



Sue McIntyre, Author provided

Sue McIntyre, Australian National University

Last week we learned woody vegetation in New South Wales is being cleared at more than double the rate of the previous decade – and agriculture was responsible for more than half the destruction.

Farming now covers 58% of Australia, or 385 million hectares, and accounts for 59% of water extracted.

It’s painfully clear nature is buckling under the weight of farming’s demands. In the past decade, the federal government has listed ten ecological communities as endangered, or critically endangered, as a result of farming development and practices.

So how can we accommodate the needs of both farming and nature? Research shows us how – but it means accepting land as a finite resource, and operating within its limits. In doing so, farmers will also reap benefits.

Grassy eucalypt woodlands used for cattle farming in subtropical Queensland.
Tara Martin. Author provided.

Healthy grazing landscapes

In the 1990s, I worked as a research ecologist in the cattle country of sub-tropical Queensland. The prevailing culture valued agricultural development over conservation. Yet many of these producers lived on viable farms that supported a wealth of native plants and animals.

They made a living from the native grassy eucalypt woodlands, an ecosystem that extends from Cape York to Tasmania. In these healthy landscapes, vigorous pastures of tall perennial grasses protected the soil, enriched it with carbon and fed the cattle.




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NSW and Victoria have similar eucalypt grassy vegetation, but farming here has taken a very different path.

Fertilised legumes and grasses grown for livestock fodder have replaced hundreds of native grassland plants. Over time, native trees and shrubs stopped regenerating and remaining trees became unhealthy, destroying wildlife habitat. The transformation was hastened by aerial applications of fertiliser and herbicide.

By 2006, 4.5 million hectares of box-gum grassy woodland – or 90% – in temperate Australia had been destroyed.

Aerial delivery of fertiliser, seed and herbicide transformed grassy woodlands in NSW.
F. G. Swain. Author provided.

A template for sustainability

Back in Queensland in the 1990s, my colleagues and I devised a template for sustainable land use. Funded by the livestock industry and a now-defunct federal corporation, we worked with producers and government agencies to find the right balance between farm production and conserving natural resources.

Our research concluded that for farming to be sustainable, intensive land uses must be limited. Such intensive uses include crops and non-native pastures. They are “high input”, typically requiring fertilisers, herbicides and pesticides, and some form of cultivation. They return greater yields but kill native plants, and are prone to soil and nutrient runoff into waterways.

But our template was not adopted as conventional farming practice. In the past 20 years, Australia’s cropping area has increased by 18,200 square kilometres.

By 2019, 38,000 square kilometres of poplar box grassy woodland in Australia had been cleared – more than half the size of Tasmania. The ecosystem was listed as endangered in 2019. Until that point, it had been considered invasive native scrub in NSW – exempting it from clearing regulations – and was systematically cleared for agriculture in Queensland.

Farmers should conserve sufficient areas of landscape to support native plants and animals.
Sue McIntyre, Author provided

Regenerating the land

Hearteningly, our research was recently revived in a multidisciplinary study of regenerative grazing on the grassy woodlands of NSW. The template was used to assess the ecological condition of participating farms.

The study examined differences in profitability between graziers who had adopted regenerative techniques such as low-input pasture management, and all other sheep, sheep-beef and mixed cropping-grazing farmers in their region.




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It found regenerative grazing was often more profitable than other types of farming, especially in dry years. Regenerative farmers also experienced significantly higher than average well-being compared with other NSW farmers.

So what does our template involve? First, it identifies four types of land use relevant to farmed grassy woodland regions.

Second, it specifies the proportion of land that should be allocated to each use, in order to achieve landscape health (see pie chart below). The proportions can be applied to single farm, or entire districts or regions.

How to sustain production, natural resources and native flora and fauna on a landscape or farm.
Sue McIntyre

Intensive land use involves activities that replace nearly all native species. If these activities occupy more than 30% of the landscape, there’s insufficient habitat to maintain many native species, especially plants.

At least 10% of land must be devoted to nature conservation. The remaining 60% of the land should involve low-intensity activity such as grazed native pasture and timber production. If managed well, these land uses can support human livelihoods and a diversity of native species.

Within that split of land use, total native woodland should be no less than 30%. This guarantees connected habitats for native plants and animals, enabling movement and breeding opportunities.

Retaining grassy woodland ensures habitat for native animals.
Duncan McCaskill/Flickr

Respect the land’s limits

Australians ask a lot of our land. It must make space for our houses, businesses, and roads. It should support all species to prevent extinctions. And it must produce our food and fibre.

Global population growth demands a rapid rise in food production. But relying on intensive agriculture to achieve this is unsustainable. Aside from damaging the land, it increases greenhouse gas emissions though mechanisation, fertilisation, chemical use and tree clearing.




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Australian farmers are adapting to climate change


To meet the challenges of the future we must ensure farmed landscapes retain their ecological functions. In particular, maintaining biodiversity is key to climate adaptation. And as many of Australia’s plants and animals march towards extinction, the need to reverse biodiversity loss has never been greater.

Farmers can be profitable while maintaining and improving the ecological health of their land. It’s time to look harder at farming models that respect the limits of nature, and recognise that less can be more.The Conversation

Sue McIntyre, Honorary Professor, Australian National University

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

Illegal hunters are a bigger problem on farms than animal activists – so why aren’t we talking about that?



Sipa USA

Kyle J.D. Mulrooney, University of New England and Alistair Harkness, University of New England

This month, the Victorian government announced on-the-spot fines for trespassers on farms following an upper house inquiry into how animal activism affects agriculture.

It’s the latest in a string of new state and federal laws designed to crack down on activists who trespass on farms – often to gather video evidence of alleged animal cruelty, which is later distributed to the public.

But amid the flurry of attention on activists, another group of trespassers on farms has largely escaped attention: illegal hunters.

Unauthorised access to farm properties can create many problems – not least, it runs the risk spreading disease such as African swine fever that can devastate farming industries.

It’s important that laws to tackle farm trespass are evidence-based. So let’s look at the evidence.

Farm trespass is a major rural crime issue.
Shutterstock

Media and political focus

Media coverage of activists trespassing on farms has appeared regularly in recent years.

Over several months in 2018-19, activists targeted the Gippy Goat farm and cafe in Victoria – in one incident stealing three goats and a lamb. News reports covered the protests, claims by farmers that the fines issued to the activists was inadequate, and the eventual closure of the farm to the public.

In another example last year, the front page of rural newspaper the Weekly Times featured a family exiting the farming industry after alleged trespass and threats from animal activists.




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Activists did not escape the attention of politicians. Ahead of Victoria’s new legislation this month, federal parliament last year passed a bill criminalising the “incitement” of both trespass, and damage or theft of property, on agricultural land.

Speaking in support of the bill, Attorney-General Christian Porter said trespass onto agricultural land could contaminate food and breach biosecurity protocols. He specifically cited “activists” when describing how the laws would work.

The New South Wales government last year also introduced significant fines for trespass on farms in the Right to Farm Act. And in South Australia, the government wants those who trespass or disrupt farming activities to face tougher penalties.

But as lawmakers crack down on animal activists, the problem of trespass by illegal hunters gets little political attention.

Animal rights protesters have been the subject of intense media attention, but illegal hunters fly under the radar.
David Beniuk/AAP

The illegal hunting problem

Illegal hunting includes hunting without a required licence and accessing private property without permission.

In 2015 and 2016, this article’s co-author Alistair Harkness surveyed 56 Victoria farmers about their experiences and perceptions of farm crime. Farmers reported that in recent years, illegal hunters had caused them economic loss and emotional anguish by:

  • damaging fences
  • shooting at buildings, beehives and livestock
  • stealing from sheds
  • failing to extinguish campfires
  • destroying fields with their vehicles.

A follow-up mail survey of 906 Victorian farmers in 2017 and 2018 asked them to rate the seriousness of a range of issues. Farmers reported the following issues as either serious or very serious: illegal shooting on farms (34.4%), animal activism (30.9%), and trespass (44.2%).




Read more:
Animal activists v private landowners: what does the law say?


Lead author Kyle Mulrooney is conducting the NSW Farm Crime Survey 2020. The work is ongoing, but so far farmers have reported feeling victimised by trespassers generally, and fear about illegal hunters. Farmers were not specifically asked for their views on trespassing activists.

A submission to a NSW parliamentary inquiry last year underscored the distress felt by farmers when hunters trespass on their properties. Farmer John Payne recalled:

Recently we had a period over several nights, where unknown persons trespassed on our property and callously killed a substantial number of our goat kids, in one case trussing one up before killing them. All just for fun and sport! […] This is one of several events where people have trespassed and shot our animals for fun, or hunted for pigs or wildlife, with little fear of detection, arrest and prosecution.

Police follow the evidence

Figures supplied to us by NSW Police show in 2018, 513 incidents of criminal trespass on farms was recorded – up from 421 in 2014.

Giving evidence to the NSW parliamentary inquiry, Detective Inspector Cameron Whiteside, the State Rural Crime Coordinator, said illegal hunting was “the most cited factor associated with the trespass” on farms.

Police action appears to be following the evidence. In communication with the lead author, Whiteside has said enforcement and operations focused on illegal hunting and trespass are a primary and current focus of the Rural Crime Prevention Team.

Target all trespassers

As African swine fever sweeps Asia, Australian pork producers have been urged to ramp up biosecurity efforts on their own properties. This reportedly includes restricting visitor numbers and separating visitor and farm vehicles.

There are fears that if the disease hits Australia, it could could shut down Australia’s A$5.3 billion pork industry, leading to mass job losses.

Given these risks, it’s important that policies to crack down on farm trespassers are guided by evidence, and don’t unduly target a single group.

And importantly, more research into the issue is needed – including into the social and economic impacts of farm trespass, in all its forms.




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The Conversation


Kyle J.D. Mulrooney, Lecturer in Criminology, Co-director of the Centre for Rural Criminology, University of New England and Alistair Harkness, Senior Lecturer in Criminology, Centre for Rural Criminology, University of New England

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

Ban on toxic mercury looms in sugar cane farming, but Australia still has a way to go



Phil / CC BY (https://creativecommons.org/licenses/by/2.0)

Larissa Schneider, Australian National University; Cameron Holley, UNSW; Darren Sinclair, University of Canberra, and Simon Haberle, Australian National University

This month, federal authorities finally announced an upcoming ban on mercury-containing pesticide in Australia. We are one of the last countries in the world to do so, despite overwhelming evidence over more than 60 years that mercury use as fungicide in agriculture is dangerous.

Mercury is a toxic element that damages human health and the environment, even in low concentrations. In humans, mercury exposure is associated with problems such as kidney damage, neurological impairment and delayed cognitive development in children.




Read more:
Australia emits mercury at double the global average


The ban will prevent about 5,280 kilograms of mercury entering the Australian environment each year.

But Australia is yet to ratify an international treaty to reduce mercury emissions from other sources, such as the dental industry and coal-fired power stations. This is our next challenge.

Prime Minister Scott Morrison visiting a sugar cane farm in 2019. Mercury-containing pesticides will be banned.
Cameron Laird/AAP

A mercury disaster

Mercury became a popular pesticide ingredient for agriculture in the early 1900s, and a number of poisoning events ensued throughout the world.

They include the Iraq grain disaster in 1971-72, when grain seed treated with mercury was imported from Mexico and the United States. The seed was not meant for human consumption, but rural communities used it to make bread, and 459 people died.

In the decades since, most countries have banned the production and/or use of mercury-based pesticides on crops. In 1995 Australia discontinued their use in most applications, such as turf farming.

Emissions of the element mercury are a threat to human health and the environment.
Wikimedia

Despite this, authorities exempted a fungicide containing mercury known as Shirtan. They restricted its use to sugar cane farming in Queensland, New South Wales, Western Australia and the Northern Territory.

According to the sugar cane industry, about 80% of growers use Shirtan to treat pineapple sett rot disease.

But this month, the Australian Pesticides and Veterinary Medicines Authority cancelled the approval of the mercury-containing active ingredient in Shirtan, methoxyethylmercuric chloride. The decision was made at the request of the ingredient’s manufacturer, Alpha Chemicals.

Shirtan’s registration was cancelled last week. It will no longer be produced in Australia, but existing supplies can be sold to, and used by, sugar cane farmers for the next year until it is fully banned.

Workers and nature at risk

Over the past 25 years, Australia’s continued use of Shirtan allowed about 50,000 kilograms of mercury into the environment. The effect on river and reef ecosystems is largely unknown.

What is known is that mercury can be toxic even at very low concentrations, and research is needed to understand its ecological impacts.

The use of mercury-based pesticide has also created a high risk of exposure for sugar cane workers. At most risk are those not familiar with safety procedures for handling toxic materials, and who may have been poorly supervised. This risk has been exacerbated by the use itinerant workers, particularly those from a non-English speaking background.

South Sea Islanders hoeing a cane field in Queensland, 1902. Cane workers have long been exposed to mercury.
State Library of Queensland

Further, in the hot and humid conditions of Northern Australia, it has been reported that workers may have removed protective gloves to avoid sweating. Again, research is needed to determine the implication of these practices for human health.

To this end, Mercury Australia, a multi-disciplinary network of researchers, has formed to address the environmental, health and other issues surrounding mercury use, both contemporary and historical.

Australia is yet to ratify

The Minamata Convention on Mercury is a global treaty to control mercury use and release into the environment. Australia signed onto the convention in 2013 but is yet to ratify it.

Until the treaty is ratified, Australia is not legally bound to its obligations. It also places us at odds with more than 100 countries that have ratified it, including many of Australia’s developed-nation counterparts.

Australia’s outlier status in this area is shown in the below table:

Accession, acceptance or ratification have the same legal effect, where parties follow legal obligations under international law.

Mercury-based pesticide use was one of Australia’s largest sources of mercury emissions. But if Australia ratifies the convention, it would be required to control other sources of mercury emissions, such as dental amalgam and the burning of coal in power stations.

The three active power stations in the Latrobe Valley, for example, together emit about 1,200 kilograms of mercury each year.

The coal-burning Mount Piper Power station near Lithgow in NSW. Government efforts to reduce mercury emissions should focus on coal plants.
David Gray/Reuters

Time to look at coal

If Australia ratified the Minamata Convention, it would provide impetus for a timely review and, if necessary, update of mercury regulations across Australia.

Emissions from coal-fired power stations in Australia are regulated by the states through pollution control licences. Some states would likely have to amend these licences if Australia ratified the convention. For example, Victorian licences for coal-fired power stations currently do not include limits on mercury emissions.

Pollution control technologies were introduced at Australian coal plants in the early 1990s. But they do not match state-of-the-art technologies applied to coal plants in North America and Europe.




Read more:
Why won’t Australia ratify an international deal to cut mercury pollution?


Australian environment authorities have been examining the implications of ratifying the convention. But progress is slow.

The issue of mercury emissions does not attract significant public or political attention. But there is a global scientific consensus that coordinated international action is needed.

The pesticide phase-out and ban is an important step. But Australia still has a way to go.The Conversation

Larissa Schneider, DECRA fellow, Australian National University; Cameron Holley, Professor, UNSW; Darren Sinclair, Professor, University of Canberra, and Simon Haberle, Professor, Australian National University

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

Pass the shiraz, please: how Australia’s wine industry can adapt to climate change



Victor Fraile/Reuters

Gabi Mocatta, University of Tasmania; Rebecca Harris, University of Tasmania, and Tomas Remenyi, University of Tasmania

Many Australians enjoy a glass of homegrown wine, and A$2.78 billion worth is exported each year. But hotter, drier conditions under climate change means there are big changes ahead for our wine producers.

As climate scientists and science communicators, we’ve been working closely with the wine industry to understand the changing conditions for producing quality wine in Australia.




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We created a world-first atlas to help secure Australia’s wine future. Released today, Australia’s Wine Future: A Climate Atlas shows that all 71 wine regions in Australia must adapt to hotter conditions.

Cool wine regions such as Tasmania, for example, will become warmer. This means growers in that state now producing pinot noir and chardonnay may have to transition to varieties suited to warmer conditions, such as shiraz.

Australian wine regions will become hotter under climate change.
AAP

Hotter, drier conditions

Our research, commissioned by Wine Australia, is the culmination of four years of work. We used CSIRO’s regional climate model to give very localised information on heat and cold extremes, temperature, rainfall and evaporation over the next 80 years.

The research assumed a high carbon emissions scenario to 2100, in line with Earth’s current trajectory.

From 2020, the changes projected by the climate models are more influenced by climate change than natural variability.

Temperatures across all wine regions of Australia will increase by about 3℃ by 2100. Aridity, which takes into account rainfall and evaporation, is also projected to increase in most Australian wine regions. Less frost and more intense heatwaves are expected in many areas.




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By 2100, growing conditions on Tasmania’s east coast, for example, will look like those currently found in the Coonawarra region of South Australia – a hotter and drier region where very different wines are produced.

That means it may get harder to grow cool-climate styles of varieties such as chardonnay and pinot noir.

Some regions will experience more change than others. For example, the Alpine Valleys region on the western slopes of the Victorian Alps, and Pemberton in southwest Western Australia, will both become much drier and hotter, influencing the varietals that are most successfully grown.

A map showing current average growing season temperature across Australia’s 71 wine regions.
Authors provided

Other regions, such as the Hunter Valley in New South Wales, will not dry out as much. But a combination of humidity and higher temperatures will expose vineyard workers in those regions to heat risk on 40-60 days a year – most of summer – by 2100. That figure is currently about 10 days a year, up from 5 days historically.

Grape vines are very adaptable and can be grown in a variety of conditions, such as arid parts of southern Europe. So while adaptations will be needed, our projections indicate all of Australia’s current wine regions will be suitable for producing wine out to 2100.

Lessons for change

Australia’s natural climate variability means wine growers are already adept at responding to change. And there is much scope to adapt to future climate change.

In some areas, this will mean planting vines at higher altitudes, or on south facing slopes, to avoid excessive heat. In future, many wine regions will also shift to growing different grape varieties. Viticultural practices may change, such as training vines so leaves shade grapes from heat. Growers may increase mulching to retain soil moisture, and areas that currently practice dryland farming may need to start irrigating.

The atlas enables climate information and adaptation decisions to be shared across regions. Growers can look to their peers in regions currently experiencing the conditions they will see in future, both in Australia and overseas, to learn how wines are produced there.

If our wine industry adapts to climate change, Australians can continue to enjoy homegrown wine.
James Gourley/AAP

Industries need not die on the vine

Agriculture industries such as wine growing are not the only ones that need fine-scale climate information to manage their climate risk. Forestry, water management, electricity generation, insurance, tourism, emergency management authorities and Defence also need such climate modelling, specific to their operations, to better prepare for the future.

The world has already heated 1℃ above the pre-industrial average. Global temperatures will continue to rise for decades, even if goals under the Paris climate agreement are met.

If Earth’s temperature rise is kept below 1.5℃ or even 2℃ this century, many of the changes projected in the atlas could be minimised, or avoided altogether.

Australia’s wine industry contributes A$45 billion to our economy and supports about 163,000 jobs. Decisions taken now on climate resilience will dictate the future of this critical sector.




Read more:
Just how hot will it get this century? Latest climate models suggest it could be worse than we thought


The Conversation


Gabi Mocatta, Research Fellow in Climate Change Communication, Climate Futures Programme, University of Tasmania; Rebecca Harris, Senior lecturer, Manager, Climate Futures Program, University of Tasmania, and Tomas Remenyi, Climate Research Fellow, Climate Futures Programme, University of Tasmania

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

More than 1,200 tonnes of microplastics are dumped into Aussie farmland every year from wastewater sludge


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Abbas Mohajerani, RMIT University

Every year, treated wastewater sludge called “biosolids” is recycled and spread over agricultural land. My recent research discovered this practice dumps thousands of tonnes of microplastics into farmlands around the world. In Australia, we estimate this amount as at least 1,241 tonnes per year.

Microplastics in soils can threaten land, freshwater and marine ecosystems by changing what they eat and their habitats. This causes some organisms to lose weight and have higher death rates.

But this is only the beginning of the problem. Microplastics are good at absorbing other pollutants – such as cadmium, lead and nickel – and can transfer these heavy metals to soils.

Wastewater treatment plants create biosolids, which are packed full of microplastics and toxic chemicals.
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And while microplastics alone is an enormous issue, other contaminants have also been found in biosolids used for agriculture. This includes pharmaceutical chemicals, personal care products, pesticides and herbicides, surfactants (chemicals used in detergents) and flame retardants.

We must stop using biosolids for farmlands immediately, especially when alternative ways to recycle wastewater sludge already exist.

Where do the microplastics come from?

Biosolids are mainly a mix of water and organic materials.

But many household items that contain microplastics – such as lotions, soaps, facial and body washes, and toothpaste – end up in wastewater, too. Other major sources of microplastics in wastewater are synthetic fibres from clothing, plastics in the manufacturing and processing industries, and the breakdown of larger plastic debris.

Before they’re taken to farmlands, wastewater collection systems carry all, or most, of these microplastics and other chemicals from residential, commercial and industrial sources to wastewater treatment plants.

To determine the weight of microplastics in Australia and other countries, my data analysis used the average minimum and maximum numbers of microplastics particles, per kilogram of biosolids samples, found in Germany, Ireland and the USA.




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We have no idea how much microplastic is in Australia’s soil (but it could be a lot)


Australia produced 371,000 tonnes of biosolids in 2019. And globally, we estimate between 50 to more than 100 million tonnes of biosolids are produced each year.

Why microplastics are harmful

Microplastics in soil can accumulate in the food web. This happens when organisms consume more microplastics than they lose. This means heavy metals attached to the microplastics in soil organisms can progress further up the food chain, increasing the risk of human exposure to toxic heavy metals.

When microplastics accumulate heavy metals, they transfer these contaminants to plants and crops, such as rice and grains, as biosolids are spread over farmland.




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Over time, microplastics break down and become even tinier, creating nanoplastics. Crops have also been shown to absorb nanoplastics and move them to different plant tissues.

Our research results also show that after the wastewater treatment process, the absorption potential of microplastics for metals increases.

The metal cadmium, for example, is particularly susceptible to microplastics in biosolids and can be transported to plant cells. Research from 2018 showed microplastics in biosolids can absorb cadmium ten times more than virgin microplastics (new microplastics that haven’t gone through wastewater treatment).

Biosolids have a cocktail of nasty chemicals

It’s not just plastic – many industrial additives and chemicals have been found in wastewater and biosolids.

This means they may accumulate in soils and affect the equilibrium of biological systems, with negative effects on plant growth. For example, researchers have found pharmaceutical chemicals in particular can reduce plant growth and inhibit root elongation.




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Other chemical contaminants – such as PFCs, PFAS and BPA – have likewise been detected in biosolids.

The effects these chemicals have on plants may lead to problems further down the food chain, such as humans and other animals inadvertently consuming pharmaceuticals and harmful chemicals.

What can we do about it?

Given the cocktail of toxic chemicals, heavy metals and microplastics, using biosolids in agricultural soils must be stopped without delay.

The good news is there’s another way we can recycle the world’s biosolids: turning them into sustainable fired-clay bricks, called “bio-bricks”.

Bricks incorporated with biosolids are a sustainable solution to an environmental problem.
RMIT media, Author provided

My team’s research from last year found bio-bricks a sustainable solution for both the wastewater treatment and brick manufacturing industries.

If 7% of all fired-clay bricks were biosolids, it would redirect all biosolids produced and stockpiled worldwide annually, including the millions of tonnes that currently end up in farmland each year.




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We also found they’d be more energy efficient. The properties of these bio-bricks are very similar to standard bricks, but generally requires 12.5% less energy to make.

And generally, comprehensive life-cycle assessment has shown biosolid bricks are more environmentally friendly than conventional bricks. These bricks will reduce or eliminate a significant source of greenhouse gas emissions from biosolids stockpiles and will save some virgin resources, such as clay soil and water, for the brick industry.

Now, it’s up to the agriculture, wastewater and brick industries, and governments to make this important transition.The Conversation

Abbas Mohajerani, Associate Professor, School of Engineering, RMIT University

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

Climate explained: how the climate impact of beef compares with plant-based alternatives



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Alexandra Macmillan, University of Otago and Jono Drew, University of Otago

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz

I am wondering about the climate impact of vegan meat versus beef. How does a highly processed patty compare to butchered beef? How does agriculture of soy (if this is the ingredient) compare to grazing of beef?

Both Impossible Foods and Beyond Meat, two of the biggest players in the rapidly expanding meat alternatives market, claim their vegan burger patties (made primarily from a variety of plant proteins and oils) are 90% less climate polluting than a typical beef patty produced in the United States.

The lifecycle assessments underpinning these findings were funded by the companies themselves, but the results make sense in the context of international research, which has repeatedly shown plant foods are significantly less environmentally damaging than animal foods.

It is worth asking what these findings would look like if the impacts of plant-based meats had been compared with a beef patty produced from a grass-fed
cattle farm, as is the case in New Zealand, instead of an industrialised feedlot operation that is commonplace in the United States.




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A New Zealand perspective

Building on international research mainly carried out in the Northern Hemisphere, we recently completed a full assessment of the greenhouse gas emissions associated with different foods and dietary patterns in New Zealand.

Despite dominant narratives about the efficiency of New Zealand’s livestock production systems, we found the stark contrast between climate impacts of plant and animal foods is as relevant in New Zealand as it is elsewhere.

For example, we found 1 kilogram of beef purchased at the supermarket produces 14 times the emissions of whole, protein-rich plant foods like lentils, beans and chickpeas. Even the most emissions-intensive plant foods, such as rice, are still more than four times more climate-friendly than beef.

The New Zealand food emissions database: comparing the climate impact of commonly consumed food items in New Zealand.
Drew et al., 2020

The climate impact of different foods is largely determined by the on-farm stage of production. Other lifecycle stages such as processing, packaging and transportation play a much smaller role.

Raising beef cattle, regardless of the production system, releases large quantities of methane as the animals belch the gas while they chew the cud. Nitrous oxide released from fertilisers and manure is another potent greenhouse gas that drives up beef’s overall climate footprint.

Climate impact of the New Zealand diet

Everyday food choices can make a difference to the overall climate impact of our diet. In our modelling of different eating patterns, we found every step New Zealand adults take towards eating a more plant-based diet results in lower emissions, better population health and reduced healthcare costs.

Climate impact of different dietary scenarios, as compared with the typical New Zealand diet.
Drew et al., 2020

The graph above shows a range of dietary changes, which gradually replace animal-based and highly processed foods with plant-based alternatives. If all New Zealand adults were to adopt a vegan diet with no food wastage, we estimated diet-related emissions could be reduced by 42% and healthcare costs could drop by NZ$20 billion over the lifetime of the current New Zealand population.




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Redesigning the food system

The current global food system is wreaking havoc on both human and planetary health. Our work adds to an already strong body of international research that shows less harmful alternatives are possible.

As pressure mounts on governments around the world to help redesign our food systems, policymakers continue to show reluctance when it comes to supporting a transition toward plant-based diets.

Such inaction appears, in large part, to be driven by the propagation of deliberate misinformation by powerful food industry groups, which not only confuses consumers but undermines the development of healthy and sustainable public policy.

To address the multiple urgent environmental health issues we face, a shift towards a plant-based diet is something many individuals can do for their and the planet’s health, while also pressing for the organisational and policy changes needed to make such a shift affordable and accessible for everyone.The Conversation

Alexandra Macmillan, Associate Professor Environment and Health, University of Otago and Jono Drew, Medical Student, University of Otago

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

Climate change is hurting farmers – even seeds are under threat



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Richard Ellis, University of Reading

Climate change is already affecting the amount of food that farmers can produce. Several recent extreme weather events, which are only likely to become more frequent as the world continues heating up, provide stark illustrations of what this impact can look like. Climate change is already affecting the amount of food that farmers can produce. For example, crop sowing in the UK was delayed in autumn 2019 and some emerging crops were damaged because of wet weather. Meanwhile in Australia, considerable drought has been immensely damaging.

But climate change can also have a knock-on impact on farming by affecting the quality of seeds, making it harder to establish seedlings that then grow into mature, food-producing plants. My research group has recently published a study showing that even brief periods of high temperature or drought can reduce seed quality in rice, depending on exactly when they occur in the seed’s development.

Nonetheless, it is possible to breed improved varieties to help crops adapt to the changing climate. And the resources needed to do this are being collected and conserved in “genebanks”, libraries of seeds conserving crop plant diversity for future use.

In much of the developing world in particular, the supply of affordable, good-quality seed limits farmers’ ability to establish crops. Seeds need to be stored between harvest and later sowing and poor-quality seeds don’t survive very long in storage. Once planted, low-quality seeds are less likely to emerge as seedlings and more likely to fail later on, producing a lower plant density in the field and a lower crop yield as a result.

For this reason, investigating seed quality is an important way of assessing such effects of climate on cereal crop production. We already know that climate change can reduce the quality of cereal seeds used for food, food ingredients and for planting future crops.

The main factor that affects seed quality in this way tends to be temperature, but the amount and timing of rainfall is also important. This impact can come from changes in average weather patterns, but short periods of extreme temperature or rainfall are just as important when they coincide with sensitive stages in crop development. For example, research in the 1990s revealed that brief high temperature periods during and immediately before a crop flowers reduces the number of seeds produced and therefore the resulting grain yield in many cereal crops.

Hot spells can make rice seeds less likely to become seedlings.
FenlioQ/Shutterstock

Our research has now confirmed that seed quality in rice is damaged most when brief hot spells coincide with early seed development. It also revealed that drought during the early development of the seeds also reduces their quality at maturity. And, unsurprisingly, the damage is even greater when both these things happen together.

In contrast, warmer temperatures later in the maturation process can benefit rice seed quality as the seeds dry out. But flooding that submerges the seed can also cause damage, which gets worse the later it occurs during maturation. This shows why we have to include the effects of changing rainfall as well as temperature and the precise timing of extreme weather when looking at how seed quality is affected.

Future seeds

Our research has also shown that different seed varieties have different levels of resilience to these environmental stresses. This means that farming in the future will depend on selecting and breeding the right varieties to respond to the changing climate.




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The world now has a global network of genebanks storing seeds from a wide variety of plants, which helps safeguard their genetic diversity. For example, the International Rice Genebank maintains more than 130,000 samples of cultivated species of rice, its wild relatives and closely-related species, while the AfricaRice genebank maintains 20,000 samples.

Our finding mean that, when scientists breed new crop varieties using genebank samples as “parents”, they should include the ability to produce high-quality seed in stressful environments in the variety’s selected traits. In this way, we should be able to produce new varieties of seeds that can withstand the increasingly extreme pressures of climate change.

This article was amended to make clear that climate change increases the likely frequency of extreme weather events rather than being demonstrably responsible for individual examples.


Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.The Conversation

Richard Ellis, Professor of Crop Production, University of Reading

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

New study: changes in climate since 2000 have cut Australian farm profits 22%



The Australian Bureau of Agricultural and Resource Economics and Sciences farmpredict model finds that changes in climate conditions since 2000 have cut farm profits by 22% overall, and by 35% for cropping farms..
ABARES/Shutterstock

Neal Hughes, Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES) and Steve Hatfield-Dodds, Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES)

The current drought across much of eastern Australia has demonstrated the dramatic effects climate variability can have on farm businesses and households.

The drought has also renewed longstanding discussions around the emerging effects of climate change on agriculture, and how governments can best help farmers to manage drought risk.

A new study released this morning by the Australian Bureau of Agricultural and Resource Economics and Sciences offers fresh insight on these issues by quantifying the impacts of recent climate variability on the profits of Australian broadacre farms.




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The results show that changes in temperature and rainfall over the past 20 years have had a negative effect on average farm profits while also increasing risk.

The findings demonstrate the importance of adaptation, innovation and adjustment to the agriculture sector, and the need for policy responses which promote – and don’t unnecessarily inhibit – such progress.

Measuring the effects of climate on farms

Measuring the effects of climate on farms is difficult given the many other factors that also influence farm performance, including commodity prices.

Further, the effects of rainfall and temperature on farm production and profit can be complex and highly location and farm specific.

To address this complexity, ABARES has developed a model based on more than 30 years of historical farm and climate data—farmpredict — which can identify effects of climate variability, input and output prices, and other factors on different types of farms.

Cropping farms most exposed

The model finds that cropping farms generally face greater climate risk than beef farms, but also generate higher average returns.

Cropping farm revenue and profits are lower in dry years, with large reductions in crop yields and only small savings in input costs.


Effect of climate variability on rate of return


Based on historical climate conditions (1950 to 2019), holding non-climate factors constant. See report for more detail. ABARES FarmPredict

In contrast, drought has a smaller immediate effect on beef farm revenue, because in dry years farmers can increase the quantity of livestock sold.

However, drought also lowers herd numbers, which lowers farm profit when herd value is accounted for.

Higher temperatures, lower winter rainfall

Australian average temperatures have increased by about 1°C since 1950.

Recent decades have also seen a trend towards lower average winter rainfall in the southwest and southeast.

This drying trend has been linked to atmospheric changes associated with global warming.

However, while global climate models generally predict a decline in winter season rainfall across southern Australia and more time spent in drought, there is still much uncertainty about what will happen in the long term, particularly to rainfall.

Climate shifts have cut farm profits

ABARES has assessed the effect of climate variability on farm profits over the period 1950 to 2019, holding all other factors constant including commodity prices and farm management practices.

We find that the shift in climate conditions since 2000 (from conditions in the period 1950-1999 to conditions in the period 2000-2019) has had a negative effect on the profits of both cropping and livestock farms.


Effect of 2000 – 2019 climate conditions on average farm profit


“Farm profit percentiles for the period 2000-2019 relative to 1950-1999, holding non-climate factors constant. See report for more detail. ABARES

We estimate that the shift in climate has cut average annual broadacre farm profits by around 22%, which is an average of $18,600 per farm per year, controlling for all other factors.

The effects have been most pronounced in the cropping sector, reducing average profits by 35%, or $70,900 a year for a typical cropping farm.

At a national level this amounts to an average loss in production of broadacre crops of around $1.1 billion a year.

Although beef farms have been less affected than cropping farms overall, some beef farming regions have been affected more than others, especially south-western Queensland.




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Like previous ABARES research this study finds evidence of adaptation, with farmers reducing their sensitivity to dry conditions over time.

Our results suggest that without this adaptation the effects of the post-2000 climate shift would have been considerably larger, particularly for cropping farms.


Effect of post-2000 climate on average annual farm profits


Per cent change relative to 1950-1999 climate, holding non-climate factors constant. See report for more detail. ABARES FarmPredict

Risk and income volatility have also increased

The changed climate conditions since 2000 have also increased risk and income volatility.

This is particularly so for cropping farms, where we find the chance of low-profit years has more than doubled as a result of the change in climate conditions.


Effect of climate variability on typical cropping farm


Distribution of farm profits for 1950-1999 climate and 2000-2019 climate. See report for more detail. ABARES FarmPredict

Handle with care – the drought policy dilemma

Drought policy faces an almost unavoidable dilemma, that providing relief to farm businesses and households in times of drought risks slowing industry structural adjustment and innovation.

Adjustment, change and innovation are fundamental to improving agricultural productivity; maintaining Australia’s competitiveness in world markets; and providing attractive and financially sustainable opportunities for farm households.




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For these reasons, the strategic intent of drought policy has shifted away from seeking to protect and insulate farmers towards the promotion of drought preparedness and self‑reliance.

The best options for reconciling the drought policy dilemma focus on boosting the resilience of farm businesses and households to future droughts and climate variability, including through action and investment when farmers are not in drought.

The government’s Future Drought Fund, which will support research and innovation, is a good example of this approach.

Developing new insurance options is one worthwhile avenue of research which could provide farmers a way to self-manage risk. It would require investments in data and knowledge to support viable weather insurance markets: where farmers pay premiums sufficient to cover costs over time.




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Supporting farm households experiencing hardship is legitimate and important, but for the long term health of the farm sector this needs to be done in ways that promote resilience and improved productivity and allow for long term adjustment to change.The Conversation

Neal Hughes, Senior Economist, Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES) and Steve Hatfield-Dodds, Executive Director, Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES)

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