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.

Want an economic tonic, Mr Morrison? Use that stimulus money to turbocharge renewables



Chris Fithall/Flickr

Elizabeth Thurbon, UNSW; Hao Tan, University of Newcastle; John Mathews, Macquarie University, and Sung-Young Kim, Macquarie University

The chaos of COVID-19 has now hit global energy markets, creating an outcome unheard of in industrial history: negative oil prices. With the world’s largest economies largely in lockdown, demand for oil has stagnated.

Essentially, the negative prices mean oil producers are willing to pay for the oil to be taken off their hands because soon, they will have nowhere to store it.

Federal energy minister Angus Taylor has proposed a partial solution: Australia will spend A$94 million buying up oil, to bolster domestic supplies and help stabilise global prices.

That strategy is a fool’s path to energy security. Right now, the best way to shore up Australia’s future energy supplies is to invest economic stimulus money in renewables – essentially to manufacture our own energy security.

Prime Minister Scott Morrison with Angus Taylor, right, who wants Australia to buy surplus oil.
Mick Tsikas/AAP

A flawed plan

Australia’s oil reserves have for years languished well below the International Energy Agency’s recommended 90 days. Taylor says his plan would address this, and help stabilise (read: push up) oil prices and restore faith in the global oil market on which Australia depends.

But the plan is undermined by a simple fact: unstable global oil prices have been a recurring problem for decades, largely for political reasons well beyond Australia’s control. We need look only to the price shocks triggered by the Yom-Kippur war of 1973, the Iraq war of 2003, and the Saudi drone attack of 2019 – to name just a few.




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Making Australia a renewable energy exporting superpower


Price instability is all but guaranteed to increase in future, as climate change concerns drive insurers and investors away from fossil fuels and towards green energy.

The current chaos actually creates a much better opportunity for Australia: use the massive COVID-19 economic stimulus to manufacture real energy security in the form of renewables.

Buying large volumes of surplus oil will not ensure stable prices.
Flickr

Renewables: a win-win

The price and supply of energy from fossil fuels is vulnerable to natural resource depletion, geopolitical tensions and climate change concerns. This is true not just for oil, but coal and gas too.

The only real path to energy security is manufactured energy such as solar panels, wind turbines, electrolysers, batteries and smart grids.

These technologies can turn infinite natural resources into energy, then store and distribute it to ensure stable supply.

Victoria and South Australia now enjoy higher levels of energy security thanks to large-scale stationary batteries that even out electricity peaks and troughs.




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For example, a large-scale battery in Victoria stores energy produced by the Gannawarra solar farm. The battery provides energy during peak times when there is no sun.

Manufacturing energy is also important from an economic security perspective, promoting the creation of high-tech, high-wage industries.

These industries can create thousands of skilled jobs and open up massive new export markets – all while helping to mitigate climate change. This reality has been accepted by major East Asian economies, from China to South Korea, for more than a decade.

The Australian government must use its enormous stimulus to help local companies dramatically expand their wind, solar, hydrogen and energy storage investments.
This would satisfy domestic energy needs and grow the new green export markets ready and waiting in Asia.

Asia presents huge export potential for Australia’s renewable energy.
DAN HIMBRECHTS/AAP

A jobs boon

There is no shortage of projects waiting to be turbocharged. The government could start with Sun Cable, linking Australia’s and Singapore’s clean energy markets via an undersea cable.

It could also kickstart Australia’s clean hydrogen industry. According to the government’s own National Hydrogen Strategy, developing hydrogen would dramatically reduce Australia’s oil import reliance and energy costs and vastly expand its clean energy exports.

By simply following its own strategy, the government could create about 7,600 skilled and semi-skilled jobs and add about A$11 billion each year to Australia’s gross domestic product to 2050.




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The cheaper energy prices that follow could help Australia revive its techno-industrial base by making energy-intensive manufacturing a viable proposition once again.

According to leading economist Ross Garnaut, Australia could then bring home its long-lost materials-processing industries and re-emerge as a world-leading exporter of (clean) steel and aluminium.

Geopolitical benefits would also flow from Australia becoming a green hydrogen superpower, such as reducing our worrying export dependence on China.

An investment injection in renewables would be a huge jobs boost.
Flickr

Seize the moment

The idea of using the COVID-19 stimulus to turbocharge Australia’s clean energy shift is not pie in the sky. Indeed, doing so is the explicit recommendation of the International Energy Agency, which this week noted:

These huge spending programmes are likely to be once-in-a-generation in scale and will shape countries’ infrastructure for decades to come… Governments can … achieve both short-term economic gains and long-term benefits by making clean energy part of their stimulus plans.

COVID-19 has undoubtedly been disastrous for Australia and the world. But it creates new opportunities in energy, economic security and climate action. To seize these opportunities, the Morrison government must chart a new industrial course for the nation by manufacturing Australia’s energy security.The Conversation

Elizabeth Thurbon, Scientia Fellow and Associate Professor in International Relations / International Political Economy, UNSW; Hao Tan, Associate professor, University of Newcastle; John Mathews, Professor Emeritus, Macquarie Business School, Macquarie University, and Sung-Young Kim, Senior Lecturer in the Department of Modern History, Politics & International Relations, Macquarie University

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

No, Aussie bats won’t give you COVID-19. We rely on them more than you think



Justin Welbergen, CC BY-SA

Pia Lentini, University of Melbourne; Alison Peel, Griffith University; Hume Field, The University of Queensland, and Justin Welbergen, Western Sydney University

In this pandemic it’s tempting to look for someone, or something, to blame. Bats are a common scapegoat and the community is misled to believe getting rid of them could be a quick fix. But are bats really the problem?

Australian bats have been in the news recently for two main reasons: the misplaced fear they might carry COVID-19, and overblown reports they carry a koala-killing virus.

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This recent bad press has seen increased incidences of disturbing cruelty against Australia’s bats, as well as calls to cull or “move on” bats that live close to people. Because fewer bats would mean less disease, right? Wrong. Here’s why.

Debunking bad press

COVID-19 is caused by the SARS-CoV-2 virus. This virus is one of thousands of coronaviruses found in mammals all over the world, most with no impact on people.

A closely related virus has previously been identified in a species of horseshoe bat in China, so it’s probable the ancestor of the SARS-CoV-2 virus originated in bats.




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While several coronaviruses have been detected in various Australian bat species, none are closely related to those viruses associated with zoonotic (animal-borne) diseases like COVID-19, SARS and MERS. And none have been recorded to infect people.

More contact between humans and wildlife, through activities such as unregulated wildlife trade can lead to potentially harmful novel viruses spilling over from their natural hosts into new species.
Hume Field, Author provided

Australian bats also recently appeared in the news because of the discovery of a retrovirus in black flying-foxes related to koala immune deficiency syndrome. Some news outlets have falsely suggested bats pose a risk to koala populations.

But the original scientific paper clearly stated the proposed transmission from bats to koalas happened long ago, on evolutionary time scales. What we see in these species today are two separate viruses – there’s no evidence the virus detected in today’s bats can infect koalas, let alone cause disease.

Aussie bats have had it tough

There are about 1,400 species of bats worldwide, including 81 in Australia.

All of our bat species are native and unique. Most are small, nocturnal, and call outside of the human hearing range, so the average Australian would be lucky to see more than a couple of species in their lifetime.

This is important to remember when it comes to thinking about how often they actually interact with people.

A selection of Australia’s bat diversity (Top row from left: grey-headed flying-fox; orange leaf-nosed bat; common blossom bat; southern myotis; Bottom row: golden-tipped bat; eastern horseshoe bat; common sheath-tailed bat; ghost bat)
Justin Welbergen (grey-headed flying-fox, eastern horseshoe bat); Nicola Hanrahan (ghost bat); Bruce Thomson (golden-tipped bat); Steve Parish & Les Hall for remainder of species

Most Australians tend to think of “bats” as the two species of flying-foxes (or “fruit bats”) we commonly see in our cities: grey-headed flying-foxes (in the south) and black flying-foxes (in the north).

Flying-foxes have had a tough few months. Many Eucalypts failed to flower, so food shortages saw thousands of flying-foxes perish from starvation, and then many more died en masse in this summer’s extreme heat.

They were also heavily affected by the summer bushfires that burnt large tracts of the bats’ winter feeding areas.

What are bats doing in urban areas?

Flying-foxes show up in urban areas in search of food. Many residents equate seeing more flying-foxes to the species increasing in numbers, and are frustrated that the bats are classified as threatened.

In fact, grey-headed flying-foxes have experienced substantial population declines in recent years. While there are currently hundreds of thousands, historical data indicate that there were once millions.

Part of a flying-fox colony, asleep during the day before they fly out for breakfast at dusk.
Justin Welbergen, Author provided

Nonetheless, bats are not always easy to live close to. Their fly-outs make for spectacular shows, but colonies can also create a lot of noise, smell and mess.

This, plus misunderstandings around disease risks, including from COVID-19, has meant loud voices are calling for the eviction of bats from urban areas by any means possible.




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Why can’t we just move or cull them?

Managing bats in urban environments is no straightforward matter. Flying-foxes have complex movement dynamics, which makes “dispersing” them from urban areas extremely difficult.

Those who advocate for dispersals to be carried out often cite the Sydney and Melbourne Botanic Gardens as examples of successes. But these took place over months and years, large areas, and cost more than A$2 million each. Relatively cheaper dispersals have also been attempted, but ultimately failed.




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Culling is an equally impractical and extremely controversial suggestion. Most Australians accept that needless killing and harming of native wildlife is unacceptable, and our laws reflect this.

There are the obvious animal ethics issues, but from a practical perspective, proposing we could cull (by shooting) flying-foxes in densely-populated urban areas to effectively reduce populations is also completely unrealistic.

What’s more, attempts at both dispersals and culling are known to have the undesirable effect of splintering colonies, and driving stressed bats into surrounding areas (parks, residential backyards, school grounds). Essentially, increasing people’s exposure to bats.

Physiological stress could also promote viral shedding. Flying-fox populations are already struggling to recover from severe food shortages, extreme heat events and bushfires. So advocating such actions is misguided, with the potential to amplify, rather than alleviate disease risk.

A Mexican free-tailed bat with insect prey, and a Christmas Island flying-fox covered in pollen.
Flickr: US Department of Agriculture (left); Carol de Jong (right)

Are bats to blame?

No, bats are our friends – we rely on them more than most people realise.

Many bats are voracious predators of insects and their service to the global agricultural industry is worth billions of dollars each year.

Flying-foxes also help maintain the integrity of forests by providing long-distance pollination and seed-dispersal services. That makes them integral to the recovery of Australia’s forests from last summer’s fires.




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The fundamental issue is not the viruses in bats. SARS-CoV-2 is now a human virus, and we are responsible, knowingly or not, for its global spread.

The “epidemiological bridges” that we’ve inadvertently created – which increase our contact with wildlife through encroachment into natural areas, habitat destruction, and unregulated wildlife trade – are what’s really to blame.The Conversation

Pia Lentini, Research Fellow, School of BioSciences, University of Melbourne; Alison Peel, Senior Research Fellow in Wildlife Disease Ecology, Griffith University; Hume Field, Science and Policy Advisor for China & Southeast Asia, EcoHealth Alliance | Honorary Professor, School of Veterinary Science, The University of Queensland, and Justin Welbergen, President of the Australasian Bat Society | Associate Professor of Animal Ecology, Western Sydney University

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