What’s your beef? How ‘carbon labels’ can steer us towards environmentally friendly food choices



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Delicious, nutritious… and emissions-intensive.
Shutterstock.com

Adrian R. Camilleri, University of Technology Sydney; Dalia Patino-Echeverri, Duke University, and Rick Larrick, Duke University

What did you have for dinner last night? Might you have made a different choice if you had a simple way to compare the environmental impacts of different foods?

Most people do not recognise the environmental impact of their food choices. Our research, published in Nature Climate Change, shows that even when consumers do stop to think about the greenhouse gas emissions associated with their food, they tend to underestimate it.

Fortunately, our study also points to a potential solution. We found that a simple “carbon label” can nudge consumers in the right direction, just as nutrition information helps to highlight healthier options.




Read more:
How to reduce your kitchen’s impact on global warming


Most food production is highly industrialised, and has environmental impacts that most people do not consider. In many parts of the world, conversion of land for beef and agricultural production is a major cause of deforestation. Natural gas is a key input in the manufacture of fertiliser. Refrigeration and transportation also depend heavily on fossil fuels.

Overall, food production contributes 19-29% of global greenhouse emissions. The biggest contributor is meat, particularly red meat. Cattle raised for beef and dairy products are major sources of methane, a potent greenhouse gas.

Meat production is inherently inefficient: fertiliser is used to grow feedstock, but only a small portion of this feed becomes animal protein. It takes about 38 kilograms of plant-based protein to produce 1kg of beef – an efficiency of just 3%. For comparison, pork has 9% efficiency and poultry has 13%.

We could therefore cut greenhouse emissions from food significantly by opting for more vegetarian or vegan meals.

Food for thought

To find out whether consumers appreciate the environmental impact of their food choices, we asked 512 US volunteers to estimate the greenhouse emissions of 19 common foods and 18 typical household appliances.

We told the respondents that a 100-watt incandescent light bulb turned on for 1 hour produces 100 “greenhouse gas emission units”, and asked them to make estimates about the other items using this reference unit. In these terms, a serving of beef produces 2,481 emission units.

As shown below, participants underestimated the true greenhouse gas emissions of foods and appliances in almost every case. For example, the average estimate for a serving of beef was around 130 emission units – more than an order of magnitude less than the true amount. Crucially, foods were much more underestimated than appliances.

Consumers consistently underestimate the greenhouse emissions of food.
Camilleri et al. Nature Climate Change 2018

Improving consumers’ knowledge

People often overestimate their understanding of common everyday objects and processes. You might think you have a pretty solid idea of how a toilet works, until you are asked to describe it in exact detail.

Food is a similarly familiar but complex phenomenon. We eat it every day, but its production and distribution processes are largely hidden. Unlike appliances, which have energy labels, are plugged into an electrical outlet, emit heat, and generally have clear indications of when they are using electricity, the release of greenhouse gases in the production and transportation of food is invisible.

One way to influence food choice is through labelling. We designed a new carbon label to communicate information about the total amount of greenhouse emissions involved in the production and transport of food.

Drawing on knowledge from the design of existing labels for nutrition, fuel economy and energy efficiency, we came up with the label shown below. It has two key features.

First, it translates greenhouse emissions into a concrete, familiar unit: equivalent number of light bulb minutes. A serving of beef and vegetable soup, for example, is roughly equivalent to a light bulb turned on for 2,127 minutes – or almost 36 hours.

Second, it displays the food’s relative environmental impact compared with other food, on an 11-point scale from green (low impact) to red (high impact). Our serving of beef and vegetable soup rates at 10 on the scale – deep into the red zone – because beef production is so emissions-intensive.

In the can – a carbon label for beef and vegetable soup reveals its high environmental impact.

To test the label, we asked 120 US volunteers to buy cans of soup from a selection of six. Half of the soups contained beef and the other half were vegetarian. Everyone was presented with price and standard nutritional information. Half of the group was also presented with our new carbon labels.

Volunteers who were shown the carbon labels chose significantly fewer beef soup options. Importantly, they also had more accurate perceptions of the relative carbon footprints of the different soups on offer.




Read more:
You’ve heard of a carbon footprint – now it’s time to take steps to cut your nitrogen footprint


Figuring out the carbon footprint of every food item is difficult, expensive, and fraught with uncertainty. But we believe a simplified carbon label – perhaps using a traffic light system or showing relative scores for different foods – can help inform and empower consumers to reduce the environmental impact of their food choices.The Conversation

Adrian R. Camilleri, Senior Lecturer in Marketing, University of Technology Sydney; Dalia Patino-Echeverri, Associate professor, Duke University, and Rick Larrick, Professor of Management and Organizations, Duke University

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

Reducing food waste can protect our health, as well as our planet’s



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Smaller portions reduce food waste and waistlines.
from http://www.shutterstock.com

Liza Barbour, Monash University and Julia McCartan, Monash University

Globally, one-third of food produced for human consumption is wasted. Food waste costs Australia A$20 billion each year and is damaging our planet’s resources by contributing to climate change and inefficient land, fertiliser and freshwater use.

And it’s estimated if no further action is taken to slow rising obesity rates, it will cost Australia A$87.7 billion over the next ten years. Preventable chronic diseases are Australia’s leading cause of ill health, and conditions such as coronary heart disease, stroke, high blood pressure, some forms of cancer and type 2 diabetes are linked to obesity and unhealthy diets.

But we can tackle these two major issues of obesity and food waste together.




Read more:
Melbourne wastes 200 kg of food per person a year: it’s time to get serious


Avoid over-consumption of food

Described as metabolic food waste, the consumption of food in excess of nutritional requirements uses valuable food system resources and manifests as overweight and obesity.

The first of the Australian dietary guidelines is:

To achieve and maintain a healthy weight, be physically active and choose amounts of nutritious food and drinks to meet your energy needs.

In 2013, researchers defined three principles for a healthy and sustainable diet. The first was:

Any food that is consumed above a person’s energy requirement represents an avoidable environmental burden in the form of greenhouse gas emissions, use of natural resources and pressure on biodiversity.




Read more:
Portion size affects how much you eat despite your appetite


Reduce consumption of processed, packaged foods

Ultra-processed foods are not only promoting obesity, they pose a great threat to our environment. The damage to our planet not only lies in the manufacture and distribution of these foods but also in their disposal. Food packaging (bottles, containers, wrappers) accounts for almost two-thirds of total packaging waste by volume.

Ultra-processed foods are high in calories, refined sugar, saturated fat and salt, and they’re dominating Australia’s food supply. These products are formulated and marketed to promote over-consumption, contributing to our obesity epidemic.

Processed foods promote over-consumption and leave packaging behind.
from http://www.shutterstock.com

Healthy and sustainable dietary recommendations promote the consumption of fewer processed foods, which are energy-dense, highly processed and packaged. This ultimately reduces both the risk of dietary imbalances and the unnecessary use of environmental resources.

Author Michael Pollan put it best when he said, “Don’t eat anything your great-grandmother wouldn’t recognise as food.”




Read more:
Food addiction: how processed food makes you eat more


So what do we need to do?

In response to the financial and environmental burden of food waste, the federal government’s National Food Waste Strategy aims to halve food waste in Australia by 2030. A$133 million has been allocated over the next decade to a research centre which can assist the environment, public health and economic sectors to work together to address both food waste and obesity.

Other countries, including Brazil and the United Kingdom acknowledge the link between health and environmental sustainability prominently in their dietary guidelines.

One of Brazil’s five guiding principles states that dietary recommendations must take into account the impact of the means of production and distribution on social justice and the environment. The Qatar national dietary guidelines explicitly state “reduce leftovers and waste”.

Many would be surprised to learn Australia’s dietary guidelines include tips to minimise food waste:

store food appropriately, dispose of food waste appropriately (e.g. compost, worm farms), keep food safely and select foods with appropriate packaging and recycle.

These recommendations are hidden in Appendix G of our guidelines, despite efforts from leading advocates to give them a more prominent position. To follow international precedence, these recommendations should be moved to a prominent location in our guidelines.




Read more:
Update Australia’s dietary guidelines to consider sustainability


At a local government level, councils can encourage responsible practices to minimise food waste by subsidising worm farms and compost bins, arranging kerbside collection of food scraps and enabling better access to soft plastic recycling programs such as Red Cycle.




Read more:
Campaigns urging us to ‘care more’ about food waste miss the point


Portion and serving sizes should be considered by commercial food settings. Every year Australians eat 2.5 billion meals out and waste 2.2 million tonnes of food via the commercial and industrial sectors. Evidence shows reducing portion sizes in food service settings leads to a reduction in both plate waste and over-consumption.

Given the cost of food waste and obesity to the economy, and the impact on the health of our people and our planet, reducing food waste can address two major problems facing humanity today.The Conversation

Liza Barbour, Lecturer, Monash University and Julia McCartan, Research Officer, Monash University

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

Sustainable shopping: want to eat healthy? Try an eco-friendly diet



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Healthy eating should include thinking about the environmental cost of your food.
Al Case/Flickr, CC BY-NC-SA

Michalis Hadjikakou, Deakin University

Following our annual Christmas overindulgence, many of us have set ambitious goals for the year ahead. But eating healthy shouldn’t just mean cutting down on snacks; given the environmental impact of food production, a more sustainable diet should feature high on everyone’s list of New Year’s resolutions.

Australians have one of the largest per capita dietary environmental footprints in the world, so there’s definitely room for improvement. But, as with all diets, radical and sudden changes like going vegan or vegetarian are notoriously difficult.




Read more:
Love meat too much to be vegetarian? Go ‘flexitarian’


Smaller, more achievable behavioural shifts are more realistic. This also makes sense from an environmental perspective – large-scale drastic changes might end up shifting one type of environmental impact to another.

This guide is about making informed, feasible changes towards a more environmentally sustainable diet. It starts with the food items you put in your shopping basket.

Meat, junk and waste

Sustainability researchers, like myself, track the life cycle of food from farm to fork, measuring the energy used and emissions generated by the entire process.

Australia’s food consumption contributes significantly to greenhouse gas emissions, water scarcity, land clearing and biodiversity loss, and ocean pollution.




Read more:
Kitchen Science: from sizzling brisket to fresh baked bread, the chemical reaction that makes our favourite foods taste so good


There are many reasons our diets have such a large environmental impact, but one of the biggest is that we’re a nation of meat eaters. On average, an Aussie eats 95kg of meat a year, significantly more than the OECD average of 69kg.

Generally, animal-derived foods require more energy and resources and release significantly more emissions than most plant foods. This is particularly true for red meat: the current average consumption is 24% higher than the maximum recommended intake.

Another reason is our overconsumption of total calories, often driven by junk foods. Eating more food than we need means the environmental resources used in producing that extra food are wasted. It also leads to a range of health problems such as obesity.

Finally, the extraordinary amount of household food waste in Australia – around 3.1 million tonnes of edible food a year – also has a major impact.

What is realistic dietary change?

Sustainable dietary choices aren’t just about environmental impact – it also means being realistic and consistent. Only 11% of Australians are vegetarian, so expecting a majority to drastically reduce meat consumption is impractical, and probably alienating.

Alternatives like flexitarianism (eating meat more rarely) are more achievable for most.

An added complication is that most Australian cows are raised on pasture, which has a high carbon footprint but requires less water than growing many plant foods. So, the complete substitution of red meat or dairy with plant-based products could simply change one environmental impact for another.

Putting it all together – simple shopping advice

Moderation: Cutting out staples of the Australian diet, like meat, is not a realistic goal for many people. But try moderating your cmeat that has the highest environmental impact (beef and lamb) and instead go for chicken or pork.

Reducing junk food is good for your wallet, waist and the environment. Processed meats or dairy-based desserts have the highest footprints amongst junk foods, so when the urge to indulge hits, go for fruit-only desserts such as sorbets. Or just buy more fruit to freeze and turn into delicious and healthy smoothies that you can enjoy even more regularly. (Grapes are very high in sugar, and when frozen are great summer treats.)




Read more:
A healthy diet is cheaper than junk food but a good diet is still too expensive for some


Meal planning can also help cut down food waste, so it might be worth trying a pantry planning app.

Substitution: Think about your favourite recipes, and how you can swap out the most resource-greedy ingredients. Some meats can be replaced with alternative sources of protein such as legumes and nuts.

Sustainably-farmed or sourced seafood is another protein alternative with a lower environmental footprint compared to meat, as long as you choose your seafood wisely – for canned tuna make sure to check the label! Seasonal produce usually requires fewer resources and needs to travel less to the store, so it’s worth checking a guide to what’s in season in your region.




Read more:
Sustainable shopping: how to buy tuna without biting a chunk out of the oceans


Complex packaging of many food products, which is often unnecessary, also contributes to their environmental impact. Opt for loose fruit and vegetables and take your own shopping bags.

Experimentation: When you do buy meat, opt for novel protein sources such as game meat – we are lucky to have an abundance of kangaroo as a more sustainable protein alternative in Australia. If you’re feeling even more adventurous, you could also try some insects.

This guide is a starting point for thinking about a more sustainable diet, but food systems are incredibly complex. Animal welfare and the viability of farming communities are just part of the social and economic issues we much deal with.

The ConversationUltimately, while consumers can drive change, this will be incremental: transformative change can only be achieved by food producers and retailers also coming on board to drive a more sustainable food system.

Michalis Hadjikakou, Research fellow, School of Life and Environmental Sciences, Faculty of Science, Engineering & Built Environment, Deakin University

This article was originally published on The Conversation. Read the original article.

Home biogas: turning food waste into renewable energy



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The home biogas system offers a zero-emissions alternative to paying for fossil gas.
Samuel Alexander, Author provided

Samuel Alexander, University of Melbourne

Last night I cooked my family a delicious pasta dinner using biogas energy. This morning we all had eggs cooked on biogas. I’m not sure what’s for dinner tonight, but I know what will provide the energy for cooking: biogas.

And not just any biogas – it’s home biogas, produced in our suburban backyard, as part of my ongoing “action research” into sustainable energy practices.


Read more: Biogas: smells like a solution to our energy and waste problems


In an age of worrying climate change and looming fossil energy decline, the benefits of biogas are obvious. It is a renewable energy source with zero net greenhouse emissions. And yet its potential has largely gone untapped, at least in the developed world.

Based on my research and experience, I contend that home-produced biogas is an extremely promising technology whose time has come. In fact, I believe it could provoke a domestic green energy revolution, if only we let it.

What is biogas?

Biogas is produced when organic matter biodegrades under anaerobic conditions (that is, in the absence of oxygen). This process produces a mixture of gases – primarily methane, some carbon dioxide and tiny portions of other gases such as hydrogen sulfide.

When the biogas is filtered to remove the hydrogen sulfide, the resulting mixture can be burned as an energy source for cooking, lighting, or heating water or space. When compressed it can be used as fuel for vehicles. On a commercial scale biogas can be used to generate electricity or even refined and fed into the gas grid.

The types of organic matter used to produce biogas include food waste, animal manure and agricultural byproducts. Some commercial systems use sewage to produce and capture biogas.

Biogas benefits

The primary benefit of biogas is that it is renewable. Whereas the production of oil and other fossil fuels will eventually peak and decline, we will always be able to make biogas as long as the sun is shining and plants can grow.

Biogas has zero net greenhouse emissions because the CO₂ that is released into the atmosphere when it burns is no more than what was drawn down from the atmosphere when the organic matter was first grown.

As already noted, when organic matter biodegrades under anaerobic conditions, methane is produced. It has been estimated that each year between 590 million and 800 million tones of methane is released into the atmosphere. This is bad news for the climate – pound for pound, methane is a far more potent greenhouse gas than CO₂.

But in a biogas system this methane is captured and ultimately converted to CO₂ when the fuel is burned. Because that CO₂ was going to end up in the atmosphere anyway through natural degradation, biogas has zero net emissions.

There are other benefits too. The organic matter used in biogas digesters is typically a waste product. By using biogas we can reduce the amount of food waste and other organic materials being sent to landfill.

Furthermore, biogas systems produce a nutrient-rich sludge that can be watered down into a fertiliser for gardens or farms. All of this can help to develop increased energy independence, build resilience and save money.

My biogas experiment

In the spirit of scientific research, I installed one of the few home biogas systems currently available, at a cost of just over A$1,000 delivered, and have been impressed by its ease and functionality. (Please note that I have no affiliation, commercial or otherwise, with the manufacturer.)

In practical terms, I put in about 2kg of food waste each day and so far I have had enough gas to cook with, sometimes twice a day. If I ever needed more gas, I could put in more organic matter. I will continue to monitor the system as part of my research and will publish updates in due course. If interested, watch this space.

My personal motivation to explore biogas (related to my research) arises primarily from a desire to decarbonise my household’s energy use. So far, so good. We have disconnected from the conventional gas grid and now have more money to spend on projects such as expanding our solar array.

Given the alarming levels of food waste in Australia, I also like the idea of turning this waste into green energy. My neighbours kindly donate their organic matter to supplement our own inputs, increasing community engagement. When necessary I cycle to my local vegetable market and enthusiastically jump into their large food waste bin to take what I need, with permission.

They think I’m mad. But, then, I think using fossil fuels is mad.

Hurdles and hopes

Home biogas is widely produced in developing regions of the world. The World Bank and the United Nations actively encourage its use as a cheap, clean energy source. China has 27 million biogas plants.

But developed regions, including Australia, have been slow to exploit this vast potential. Given that Australia is one of the most carbon-intensive countries on Earth, this is unfortunate.

The failure to embrace home biogas is partly due to a lack of clear regulations about its use. Where is the Home Biogas Act? Almost every Australian backyard has an independent gas bottle to power the ubiquitous barbecue, so clearly storing gas in the backyard is not a problem. My biogas system came with robust safety certificates, warranties and insurance, and these systems do not feature high-pressure gas pipes.


Read more: Capturing the true wealth of Australia’s waste


Home biogas production is unusual. But I believe that state governments should draw up legislation to accommodate it, and that local councils should offer advice and assistance to householders who are interested in taking it up. Hoping for progress in this regard, I recently made a submission to the Victorian government as part of its Waste to Energy consultations.

The ConversationMy own carefully managed experiment demonstrates how home biogas can be used safely and successfully. Nevertheless, biogas is a combustible fuel and needs to be filtered for poisonous hydrogen sulfide. Like any fuel, it should be respected and used responsibly. But biogas need not be feared. Fossil gas is far more dangerous anyway.

Samuel Alexander, Research fellow, Melbourne Sustainable Society Institute, University of Melbourne

This article was originally published on The Conversation. Read the original article.

How climate change threatens to make our bread less tasty



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Increasing carbon dioxide is impacting some of our favourite foods.

Glenn Fitzgerald, University of Melbourne

Climate change and extreme weather events are already impacting our food, from meat and vegetables, right through to wine. In our series on the Climate and Food, we’re looking at what this means for the food chain. The Conversation


The concentration of carbon dioxide in our atmosphere is increasing. Everything else being equal, higher CO₂ levels will increase the yields of major crops such as wheat, barley and pulses. But the trade-off is a hit to the quality and nutritional content of some of our favourite foods.

In our research at the Australian Grains Free Air CO₂ Enrichment (AGFACE) facility, we at Agriculture Victoria and The University of Melbourne are mimicking the CO₂ levels likely to be found in the year 2050. CO₂ levels currently stand at 406 parts per million (PPM) and are expected to rise to 550PPM by 2050. We have found that elevated levels of CO₂ will reduce the concentration of grain protein and micronutrients like zinc and iron, in cereals (pulses are less affected).

The degree to which protein is affected by CO₂ depends on the temperature and available water. In wet years there will be a smaller impact than in drier years. But over nine years of research we have shown that the average decrease in grain protein content is 6% when there is elevated CO₂.

Because a decrease in protein content under elevated CO2 can be more severe in dry conditions, Australia could be particularly affected. Unless ways are found to ameliorate the decrease in protein through plant breeding and agronomy, Australia’s dry conditions may put it at a competitive disadvantage, since grain quality is likely to decrease more than in other parts of the world with more favourable growing conditions.

Increasing carbon dioxide could impact the flour your bread.
Shutterstock

Food quality

There are several different classes of wheat – some are good for making bread, others for noodles etc. The amount of protein is one of the factors that sets some wheat apart from others.

Although a 6% average decrease in grain protein content may not seem large, it could result in a lot of Australian wheat being downgraded. Some regions may be completely unable to grow wheat of high enough quality to make bread.

But the protein reduction in our wheat will become manifest in a number of ways. As many farmers are paid premiums for high protein concentrations, their incomes could suffer. Our exports will also take a hit, as markets prefer high-protein wheat. For consumers, we could see the reduction in bread quality (the best bread flours are high-protein) and nutrition. Loaf volume and texture may be different but it is unclear whether taste will be affected.

The main measure of this is loaf volume and texture, but the degree of decrease is affected by crop variety. A decrease in grain protein concentration is one factor affecting loaf volume, but dough characteristics (such as elasticity) are also degraded by changes in the protein make-up of grain. This alters the composition of glutenin and gliadin proteins which are the predominant proteins in gluten. To maintain bread quality when lower quality flour is used, bakers can add gluten, but if gluten characteristics are changed, this may not achieve the desired dough characteristics for high quality bread. Even if adding extra gluten remedies poor loaf quality, it adds extra expense to the baking process.

Nutrition will also be affected by reduced grain protein, particularly in developing areas with more limited access to food. This is a major food security concern. If grain protein concentration decreases, people with less access to food may need to consume more (at more cost) in order to meet their basic nutritional needs. Reduced micronutrients, notably zinc and iron, could affect health, particularly in Africa. This is being addressed by international efforts biofortification and selection of iron and zinc rich varieties, but it is unknown whether such efforts will be successful as CO₂ levels increase.

Will new breeds of wheat stand up to increasing carbon dioxide?

What can we do about it?

Farmers have always been adaptive and responsive to changes and it is possible management of nitrogen fertilisers could minimise the reduction in grain protein. Research we are conducting shows, however, that adding additional fertiliser has less effect under elevated CO₂ conditions than under current CO₂ levels. There may be fundamental physiological changes and bottlenecks under elevated CO₂ that are not yet well understood.

If management through nitrogen-based fertilisation either cannot, or can only partly, increases grain protein, then we must question whether plant breeding can keep up with the rapid increase in CO₂. Are there traits that are not being considered but that could optimise the positives and reduce the negative impacts?

Selection for high protein wheat varieties often results in a decrease in yield. This relationship is referred to as the yield-protein conundrum. A lot of effort has gone into finding varieties that increase protein while maintaining yields. We have yet to find real success down this path.

A combination of management adaptation and breeding may be able to maintain grain protein while still increasing yields. But, there are unknowns under elevated CO₂such as whether protein make-up is altered, and whether there are limitations in the plant to how protein is manufactured under elevated CO2. We may require active selection and more extensive testing of traits and management practices to understand whether varieties selected now will still respond as expected under future CO₂ conditions.

Finally, to maintain bread quality we should rethink our intentions. Not all wheat needs to be destined for bread. But, for Australia to remain competitive in international markets, plant breeders may need to select varieties with higher grain protein concentrations under elevated CO2 conditions, focusing on varieties that contain the specific gluten protein combinations necessary for a delicious loaf.

Glenn Fitzgerald, Honorary Associate Professor of Agriculture and Food, University of Melbourne

This article was originally published on The Conversation. Read the original article.

As global food demand rises, climate change is hitting our staple crops



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Farmers face falling crop yields and growing food demand.
Shutterstock

Andrew Borrell, The University of Queensland

Climate change and extreme weather events are already impacting our food, from meat and vegetables, right through to wine. In our series on the Climate and Food, we’re looking at what this means for the food chain. The Conversation


While increases in population and wealth will lift global demand for food by up to 70% by 2050, agriculture is already feeling the effects of climate change. This is expected to continue in coming decades.

Scientists and farmers will need to act on multiple fronts to counter falling crop yields and feed more people. As with previous agricultural revolutions, we need a new set of plant characteristics to meet the challenge.

When it comes to the staple crops – wheat, rice, maize, soybean, barley and sorghum – research has found changes in rainfall and temperature explain about 30% of the yearly variation in agricultural yields. All six crops responded negatively to increasing temperatures – most likely associated with increases in crop development rates and water stress. In particular, wheat, maize and barley show a negative response to increased temperatures. But, overall, rainfall trends had only minor effects on crop yields in these studies.

Since 1950, average global temperatures have risen by roughly 0.13°C per decade. An even faster rate of roughly 0.2°C of warming per decade is expected over the next few decades.

As temperatures rise, rainfall patterns change. Increased heat also leads to greater evaporation and surface drying, which further intensifies and prolongs droughts.

A warmer atmosphere can also hold more water – about 7% more water vapour for every 1°C increase in temperature. This ultimately results in storms with more intense rainfall. A review of rainfall patterns shows changes in the amount of rainfall everywhere.

Maize yields are predicted to decline with climate change.
Shutterstock

Falling yields

Crop yields around Australia have been hard hit by recent weather. Last year, for instance, the outlook for mungbeans was excellent. But the hot, dry weather has hurt growers. The extreme conditions have reduced average yields from an expected 1-1.5 tonnes per hectare to just 0.1-0.5 tonnes per hectare.

Sorghum and cotton crops fared little better, due to depleted soil water, lack of in-crop rainfall, and extreme heat. Fruit and vegetables, from strawberries to lettuce, were also hit hard.

But the story is larger than this. Globally, production of maize and wheat between 1980 and 2008 was 3.8% and 5.5% below what we would have expected without temperature increases. One model, which combines historical crop production and weather data, projects significant reductions in production of several key African crops. For maize, the predicted decline is as much as 22% by 2050.

Feeding more people in these changing conditions is the challenge before us. It will require crops that are highly adapted to dry and hot environments. The so-called “Green Revolution” of the 1960s and 1970s created plants with short stature and enhanced responsiveness to nitrogen fertilizer.

Now, a new set of plant characteristics is needed to further increase crop yield, by making plants resilient to the challenges of a water-scarce planet.

Developing resilient crops for a highly variable climate

Resilient crops will require significant research and action on multiple fronts – to create adaptation to drought and waterlogging, and tolerance to cold, heat and salinity. Whatever we do, we also need to factor in that agriculture contributes significantly to greenhouse gas emissions (GHGs).

Scientists are meeting this challenge by creating a framework for adapting to climate change. We are identifying favourable combinations of crop varieties (genotypes) and management practices (agronomy) to work together in a complex system.

We can mitigate the effects of some climate variations with good management practices. For example, to tackle drought, we can alter planting dates, fertilizer, irrigation, row spacing, population and cropping systems.

Genotypic solutions can bolster this approach. The challenge is to identify favourable combinations of genotypes (G) and management (M) practices in a variable environment (E). Understanding the interaction between genotypes, management and the environment (GxMxE) is critical to improving grain yield under hot and dry conditions.

Genetic and management solutions can be used to develop climate-resilient crops for highly variable environments in Australia and globally. Sorghum is a great example. It is the dietary staple for over 500 million people in more than 30 countries, making it the world’s fifth-most-important crop for human consumption after rice, wheat, maize and potatoes.

‘Stay-green’ in sorghum is an example of a genetic solution to drought that has been deployed in Australia, India and sub-Saharan Africa. Crops with stay-green maintain greener stems and leaves during drought, resulting in increased stem strength, grain size and yield. This genetic solution can be combined with a management solution (e.g. reduced plant population) to optimise production and food security in highly variable and water-limited environments.

Other projects in India have found that alternate wetting and drying (AWD) irrigation in rice, compared with normal flooded production, can reduce water use by about 32%. And, by maintaining an aerobic environment in the soil, it reduces methane emissions five-fold.

Climate change, water, agriculture and food security form a critical nexus for the 21st century. We need to create and implement practices that will increase yields, while overcoming changing conditions and limiting the emissions from the agricultural sector. There is no room for complacency here.

Andrew Borrell, Associate Professor, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland; Centre Leader, Hermitage Research Facility; College of Experts, Global Change Institute, The University of Queensland

This article was originally published on The Conversation. Read the original article.

Birdbath, food or water? How to attract your favourite birds to your garden


Grainne Cleary, Deakin University

This summer, when a rainbow lorikeet or kookaburra comes to visit your home, what will you do? Will you offer them a slice of apple, or simply watch until they take flight?

It brings many people joy to provide food and water for birds, to encourage them to stay a while and be given the chance to observe them more closely. But some people are reluctant to interact with birds in this way because they’re worried it might damage the birds’ health.

In contrast with other countries, little research has been done on the effects of feeding birds in Australia. As a result, there are no established guidelines around how to feed and provide water for local birds.

Kookaburra having a snack.
Photo supplied by Wanda Optland, provided by author.

That’s why we ran the Australian Bird Feeding and Watering Study. We asked nearly 3,000 people to monitor the birds that visited their feeding areas and birdbaths. We wanted to know if there was a difference in the species that visited different types of gardens.

We examined the numbers and types of birds visiting:

  • birdbaths where no food was provided
  • birdbaths where food was provided
  • bird-feeders where birdbaths were provided
  • places where only food was provided.

The early results from the winter stage of the Australian Bird Feeding and Watering Study suggest that if you provide food and water, you will get more birds in your garden. But the species you attract will depend on what exactly your garden has to offer.

Common bronzewings like to eat seeds.
Glenn Pure, CC BY-NC
Providing different combinations of food and water will attract different species.

Granivores

Granivores are seed-eating birds. They include species such as parrots, crested pigeons, sulphur-crested cockatoos, crimson rosellas and galahs.

Gang gang cockatoos refresh themselves in a garden.
Glenn Pure

We noticed a spike in the number of granivores in gardens where both food and birdbaths were provided. But when food was on offer, fewer granivores chose to use the birdbath. We don’t yet know exactly why this is, but it could be because these seed-eaters need less water, or they can get it more easily from other sources than they can food.

Also, most of the bird food sold in shops is seed-based. People who buy these products will naturally attract more seed-eating birds to their garden.

We were, however, surprised to see crested pigeons visiting gardens where food was provided. These birds are only recent urban arrivals, and were previously restricted to semi-arid environments as opposed to the more urban areas where most of our citizen scientists lived. But crested pigeons are very adaptable and now compete fiercely for food and territory with the introduced spotted dove in some Australian gardens.

Many people derive great joy from feeding Australian birds.

Nectarivores

“Small” nectarivores are nectar-eating birds that weigh less than 20 grams. The main birds in this group are New Holland honeyeaters, eastern spinebills and Lewin’s honeyeaters.

The early results of our study suggest small nectarivores prefer gardens with birdbaths more than their granivore and insectivore friends. In fact, it seems that these small nectarivores like birdbaths so much, they will choose birdbaths over food when both are provided.

“Large” nectarivores are nectar-eating birds that weigh more than 20 grams. These species including noisy miners, rainbow lorikeets and red wattlebirds – seem to prioritise food over birdbaths. This may be because they’re looking for a source of protein that they can’t easily find in their natural environment.

Rainbow lorikeets seem to prioritise food over birdbaths.
Photo supplied by Wanda Optland, provided by author.

Honeyeaters – such as Lewin’s honeyeaters, blue-faced honeyeaters and noisy miners – will forage on nectar but will eat insects as well. They switch from one to the other, but once they have found their meal they will defend it vigorously from other birds.

Honeyeaters will forage on nectar but will consume invertebrates as well.
Photo by Wanda Optland, supplied by author.

Insectivores

Insectivores feed on insects, worms, and other invertebrates. Some insectivore species include superb fairy-wrens, willie wagtails and grey fantails.

Insectivores are most attracted to gardens where both food and water are provided. While superb fairy-wrens were frequently found in gardens where food was provided, willie wagtails and grey fantails preferred to visit gardens where only water is provided.

The striated thornbill feeds mainly on insects.
Glenn Pure, CC BY-NC

Many people have told me how confident fairy-wrens and willie wagtails can become around houses and gardens. These tiny birds can be bold and aggressive, and can work together to get what they want. A mum and dad fairy-wrens will conscript their older children into looking after younger ones – and siblings who refuse to help find food and defend territory may even be kicked out of the family. So these tough breeds have a competitive advantage in their new urban environments, and aren’t afraid to mix with or even chase off bigger birds.

Fairy wrens can become surprisingly bold around gardens and houses.
Photo by Wanda Optland, supplied by author.
Bolder than they look – a fairy wren eats from a citizen scientist’s hand.
Peter Brazier

You may be wondering exactly what type of seed to put out to attract which granivore, or which meat attracts a carnivore like a Kookaburra. I’m afraid we can’t yet say for sure, as we are yet to analyse the data on this question. Watch this space.

We don’t yet know exactly what offering will attract which bird.
Janette and Ron Ford

Could birds become reliant on humans for food?

Many people worry that birds will become reliant on humans to provide food for them. But this mightn’t be as big a concern as we once though.

The birds turning up at feeding areas and birdbaths are species that are highly adaptable. Many Australian birds live long lives, and relatively large brains when compared to their European counterparts. Some experts have argued that some Australian birds have evolved a larger brain to cope with feast and famine conditions in the Australian environment.

White browed scrubwrens feed mostly on insects.
Glenn Pure, CC BY-NC

Many Australian bird species can switch easily between estates and gardens in one area, be semi-nomadic, fully nomadic or seasonally migratory. This ability to adapt and switch between diets makes Australian bird species very resourceful, innovative and adaptable.

Of course, Australia also has birds that have highly specialised diets or habitats, and they’re the ones usually most threatened or limited to one territory – birds like the regent honeyeater or ground parrot. In this study, we’re concentrating on birds that are adapting to urban areas and turning up at birdbaths and feeding areas in gardens.

A crested pigeon tucks in.
Brad Walker

Building our knowledge of bird feeding behaviour

We plan to develop guidelines around providing food and water for birds in a way that has the highest conservation value for our feathered friends. But before we can do that, we need more data from you.

So please take part in the summer stage of the study and pass the word around to others who may wish to be involved.

The summer survey will run for four weeks, beginning on January 30 2017. Visit feedingbirds.org.auto download the complete report on our early findings or to register to take part in our summer study.

Different species may congregate at a feeding spot.
Brad Walker

The Conversation

Grainne Cleary, Researcher, School of Life and Environmental Sciences, Deakin University

This article was originally published on The Conversation. Read the original article.