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

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Delicious, nutritious… and emissions-intensive.

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.


Greening the concrete jungle: how to make environmentally friendly cement

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With some tweaks to the recipe, cement and concrete can be made kinder to the planet.
Postman Photos/Shutterstock.com

Rackel San Nicolas, University of Melbourne

Cement is the world’s most widely used material apart from water, largely because it is the key ingredient in concrete, the world’s favourite building material.

But with cement’s success comes a huge amount of greenhouse emissions. For every tonne of cement produced in Australia, 0.82 tonnes of CO₂ is released. That might not sound like much, especially when compared with the 1.8 tonnes emitted in making a tonne of steel. But with a global production of more than 4 billion tonnes a year, cement accounts for 5% of the world’s industrial and energy greenhouse emissions.

Read more: The problem with reinforced concrete.

The electricity and heat demands of cement production are responsible for around 50% the CO₂ emissions. But the other 50% comes from the process of “calcination” – a crucial step in cement manufacture in which limestone (calcium carbonate) is heated to transform it into quicklime (calcium oxide), giving off CO₂ in the process.

A report published by Beyond Zero Emissions (BZE) (on which I was a consultant) outlines several ways in which the sector can improve this situation, and perhaps even one day create a zero-carbon cement industry.

Better recipes

The cement industry has already begun to reduce its footprint by improving equipment and reducing energy use. But energy efficiency can only get us so far because the chemical process itself emits so much CO₂. Not many cement firms are prepared to cut their production to reduce emissions, so they will have to embrace less carbon-intensive recipes instead.

The BZE report calculates that 50% of the conventional concrete used in construction can be replaced with another kind, called geopolymer concrete. This contains cement made from other products rather than limestone, such as fly ash, slag or clay.

Making this transition would be relatively easy in Australia, which has more than 400 million tonnes of fly ash readily available as stockpiled waste from the coal industry, which represents already about 20 years of stocks.

Read more: Eco-cement, the cheapest carbon sequestration on the planet.

These types of concrete are readily available in Australia, although they are not widely used because they have not been included in supply chains, and large construction firms have not yet put their faith in them.

Another option more widely known by construction firm is to use the so-called “high blend” cements containing a mixture of slag, fly ash and other compounds blended with cement. These blends have been used in concrete structures all over the world, such as the BAPS Shri Swaminarayan Mandir Hindu temple in Chicago, the foundation slab of which contains 65% fly ash cement. These blends are available everywhere in Australia but their usage is not as high as it should due to the lack of trust from the industry.

Built on the fly (ash): a Hindu temple in Chicago.
BAPS.org/Wikimedia Commons, CC BY-SA

It is even theoretically possible to create “carbon-negative cement”, made with magnesium oxide in place of traditional quicklime. This compound can absorb CO₂ from the air when water is added to the cement powder, and its developer Novacem, a spinoff from Imperial College London, claimed a tonne of its cement had a “negative footprint” of 0.6 tonnes of CO₂. But almost a decade later, carbon-negative cement has not caught on.

Capturing carbon

The CO₂ released during cement fabrication could also potentially be recaptured in a process called mineral carbonation, which works on a similar principle as the carbon capture and storage often discussed in relation to coal-fired electricity generation.

This technique can theoretically prevent 90% of cement kiln emissions from escaping to the atmosphere. The necessary rocks (olivine or serpentine) are found in Australia, especially in the New England area of New South Wales, and the technique has been demonstrated in the laboratory, but has not yet been put in place at commercial scale, although several companies around the world are currently working on it.

Read more: The ‘clean coal’ row shouldn’t distract us from using carbon capture for other industries.

Yet another approach would be to adapt the design of our buildings, bridges and other structures so they use less concrete. Besides using the high-performance concretes, we could also replace some of the concrete with other, less emissions-intensive materials such as timber.

The ConversationPreviously, high greenhouse emissions were locked into the cement industry because of the way it is made. But the industry now has a range of tools in hand to start reducing its greenhouse footprint. With the world having agreed in Paris to try and limit global warming to no more than 2℃, every sector of industry needs to do its part.

Rackel San Nicolas, Academic specialist, Infrastructure Engineering, University of Melbourne

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

Australia: Carbon Price Needed Now

Thirteen of Australia’s leading economists have signed and published an open letter calling for a speedy introduction of a carbon price for carbon polluters. They prefer to have a carbon emissions trading scheme institututed as soon as possible.

The introduction of carbon pricing is designed to accelerate a move to more environmentally friendly production methods, increased reliance on renewable energy sources, etc.

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View the actual letter.


Some Tips on ‘Green’ Camping

The following link is to an article that offers some tips on environmentally sensitive camping.

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