posts: 29680
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| 29680 | You want to reduce the carbon footprint of your food? Focus on what you eat, not whether your food is local | food-choice-vs-eating-local | post | publish | <!-- wp:html --> <div class="blog-info">Our World in Data presents the empirical evidence on global development in entries dedicated to specific topics.<br>This blog post draws on data and research discussed in our entry on the <strong><a href="http://ourworldindata.org/environmental-impacts-of-food" target="_blank" rel="noopener noreferrer">Environmental impacts of food</a> </strong>and <a href="https://owid.cloud/co2-and-other-greenhouse-gas-emissions"><strong>CO<sub>2</sub> and Greenhouse Gas Emissions</strong></a>.</div> <!-- /wp:html --> <!-- wp-block-tombstone 29685 --> <!-- wp:paragraph --> <p>People across the world are becoming increasingly concerned about climate change: 8-in-10 people see climate change as a major threat to their country.{ref}The <a href="https://www.pewresearch.org/fact-tank/2019/04/18/a-look-at-how-people-around-the-world-view-climate-change/">2018 Pew Research Center Survey</a> polled people across the world on global threats: in many countries more than 8-in-10 people said that climate change was a major threat to their country. Even in countries which showed less concern, a large percentage saw it as a major threat: 59% in the US said it was a serious threat.<br><br>This was a marked increase in concern from similar polls conducted a few years earlier.{/ref}</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>As I have shown <a href="https://ourworldindata.org/food-ghg-emissions"><strong>before</strong></a>, food production is responsible for one-quarter of the world’s greenhouse gas emissions.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>There is rightly a growing awareness that our diet and food choices have a significant impact on our carbon ‘footprint’. What can you do to really reduce the carbon footprint of your breakfast, lunches, and dinner?<br><br>‘Eating local’ is a recommendation you hear often – even from prominent sources, <a href="https://twitter.com/UN/status/1188622911080415235?s=20">including the United Nations</a>. While it might make sense intuitively – after all, transport does lead to emissions – it is one of the most misguided pieces of advice. </p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Eating locally would only have a significant impact if transport was responsible for a large share of food’s final carbon footprint. For most foods, this is <em>not</em> the case.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>GHG emissions from transportation make up a very small amount of the emissions from food and what you eat is <em>far more</em> important than where your food traveled from.</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":4} --> <h4>Where do the emissions from our food come from?</h4> <!-- /wp:heading --> <!-- wp:columns --> <div class="wp-block-columns"><!-- wp:column --> <div class="wp-block-column"><!-- wp:paragraph --> <p>In the visualization we see GHG emissions from 29 different food products – from beef at the top to nuts at the bottom.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>For each product you can see from which stage in the supply chain its emissions originate. This extends from land use changes on the left, through to transport and packaging on the right.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>This is data from the largest meta-analysis of global food systems to date, published in <em>Science </em>by Joseph Poore and Thomas Nemecek (2018).</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p> In this study, the authors looked at data across more than 38,000 commercial farms in 119 countries.{ref}Poore, J., & Nemecek, T. (2018). <a href="https://science.sciencemag.org/content/360/6392/987">Reducing food’s environmental impacts through producers and consumers</a>. <em>Science</em>, 360(6392), 987-992.{/ref} </p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>In this comparison we look at the total GHG emissions per kilogram of food product. CO<sub>2</sub> is the most important GHG, but not the only one – agriculture is a large source of the greenhouse gases methane and nitrous oxide. To capture all GHG emissions from food production researchers therefore express them in kilograms of ‘carbon dioxide equivalents’. This metric takes account not just CO<sub>2</sub> but all greenhouse gases.{ref}To express all greenhouse gases in carbon dioxide equivalents (CO<sub>2</sub>-eq), they are each weighted by their <a href="https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions#global-warming-potential-of-greenhouse-gases">global warming potential</a> (GWP) value. GWP measures the relative warming impact one molecule or unit mass of a greenhouse gas relative to carbon dioxide over a given timescale – usually over 100 years. For example, one tonne of methane would have 34 times the warming impact of tonne of carbon dioxide over a 100-year period. GWP100 values are used to combine greenhouse gases into a single metric of emissions called carbon dioxide equivalents (CO<sub>2</sub>e). CO<sub>2</sub>e is then derived by multiplying the mass of emissions of a specific greenhouse gas by its equivalent GWP100 factor. The sum of all gases in their CO<sub>2</sub>e form provide a measure of total greenhouse gas emissions.{/ref}</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>The most important insight from this study: there are massive differences in the GHG emissions of different foods: producing a kilogram of beef emits 60 kilograms of greenhouse gases (CO<sub>2</sub>-equivalents). While peas emits just 1 kilogram per kg.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Overall, animal-based foods tend to have a higher footprint than plant-based. Lamb and cheese both emit more than 20 kilograms CO<sub>2</sub>-equivalents per kilogram. Poultry and pork have lower footprints but are still higher than most plant-based foods, at 6 and 7 kg CO<sub>2</sub>-equivalents, respectively.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>For most foods – and particularly the largest emitters – most GHG emissions result from land use change (shown in green), and from processes at the farm stage (brown). Farm-stage emissions include processes such as the application of fertilizers – both organic (“manure management”) and synthetic; and enteric fermentation (the production of methane in the stomachs of cattle). Combined, land use and farm-stage emissions account for more than 80% of the footprint for most foods.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Transport is a small contributor to emissions. For most food products, it accounts for less than 10%, and it’s much smaller for the largest GHG emitters. In beef from beef herds, it’s 0.5%.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Not just transport, but all processes in the supply chain after the food left the farm – processing, transport, retail and packaging – mostly account for a small share of emissions.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>This data shows that this is the case when we look at <em>individual</em> food products. But studies also shows that this holds true for actual <em>diets</em>; for example, researcher Vilma Sandström and colleagues <a href="https://www.sciencedirect.com/science/article/pii/S2211912418300361" target="_blank" rel="noreferrer noopener">studied the footprint of diets across the EU</a>. Food transport was responsible for only 6% of emissions, whilst dairy, meat and eggs accounted for 83%.{ref}Sandström, V., Valin, H., Krisztin, T., Havlík, P., Herrero, M., & Kastner, T. (2018). <a href="https://www.sciencedirect.com/science/article/pii/S2211912418300361" target="_blank" rel="noreferrer noopener">The role of trade in the greenhouse gas footprints of EU diets</a>. <em>Global Food Security</em>, 19, 48-55.{/ref}</p> <!-- /wp:paragraph --></div> <!-- /wp:column --> <!-- wp:column --> <div class="wp-block-column"><!-- wp:image {"id":29928,"sizeSlug":"large"} --> <figure class="wp-block-image size-large"><img src="https://owid.cloud/app/uploads/2020/02/Environmental-impact-of-food-by-life-cycle-stage-612x550.png" alt="" class="wp-image-29928"/></figure> <!-- /wp:image --> <!-- wp:owid/prominent-link {"title":"Explore an interactive version of this chart and download the data","linkUrl":"https://ourworldindata.org/grapher/food-emissions-supply-chain","className":"is-style-thin"} --> <!-- wp:paragraph --> <p>Greenhouse gas emissions across the supply chain by food product.</p> <!-- /wp:paragraph --> <!-- /wp:owid/prominent-link --> <!-- wp:heading {"level":5} --> <h5>Related content:</h5> <!-- /wp:heading --> <!-- wp:owid/prominent-link {"title":"How do carbon footprints compare \u003cem\u003eper gram of\u003c/em\u003e protein?","linkUrl":"https://ourworldindata.org/environmental-impacts-of-food#carbon-footprint-of-food-products","mediaId":40955,"mediaUrl":"https://owid.cloud/app/uploads/2020/01/ghg-per-protein-poore.svg","mediaAlt":"","className":"is-style-thin"} /--> <!-- wp:owid/prominent-link {"title":"How do carbon footprints compare \u003cem\u003eper kilocalorie\u003c/em\u003e?","linkUrl":"https://ourworldindata.org/environmental-impacts-of-food#carbon-footprint-of-food-products","mediaId":40955,"mediaUrl":"https://owid.cloud/app/uploads/2020/01/ghg-per-protein-poore.svg","mediaAlt":"","className":"is-style-thin"} /--> <!-- wp:owid/prominent-link {"title":"Beyond global averages: how do the emissions of food production compare across the world?","linkUrl":"https://ourworldindata.org/less-meat-or-sustainable-meat","mediaId":29926,"mediaUrl":"https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2.png","mediaAlt":"","className":"is-style-thin"} /--></div> <!-- /wp:column --></div> <!-- /wp:columns --> <!-- wp:heading {"level":4} --> <h4>Eating local only slightly reduces your emissions</h4> <!-- /wp:heading --> <!-- wp:paragraph --> <p>Eating local beef or lamb has many times the carbon footprint of most other foods. Whether they are grown locally or shipped from the other side of the world matters very little for total emissions.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Transport typically accounts for less than 1% of beef’s GHG emissions: choosing to eat local has very minimal effects on its total footprint. You might think this figure is strongly dependent on where in the world you live, and how far your beef will have to travel, but in the ‘dropdown box’ below I work through an example to show why it doesn’t make a lot of difference.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Whether you buy it from the farmer next door or from far away, it is not the location that makes the carbon footprint of your dinner large, but the fact that it is beef.</p> <!-- /wp:paragraph --> <!-- wp:owid/additional-information --> <!-- wp:heading {"level":3} --> <h3>Example: how much does distance traveled impact the footprint of beef? </h3> <!-- /wp:heading --> <!-- wp:paragraph --> <p>You might think this figure is strongly dependent on where in the world you live, and how far your beef will have to travel. If you live somewhere very remote you’d assume this must be much, much larger than if your beef is produced by your local farmer. But the key point here is that the difference in transport figures is very small relative to the total footprint of beef.<br><br>Let’s take the example of beef from a beef herd – the average footprint is approximately 60 kilograms of CO<sub>2</sub>eq per kilogram of beef. Let’s compare the transport footprint of buying from your local farmer (who turns out to be your neighbor), versus someone in the UK buying beef from Central America (approximately 9000 kilometers away).<br><br>Transporting food by boat emits 23 grams of CO<sub>2</sub>eq per tonne of product per kilometer. To transport the 9000 kilometers from Central America to the UK therefore emits 0.207 kilograms CO<sub>2</sub>eq [9000km * 23g per tonne-kilometer / 1000 / 1000 = 0.207 kg CO<sub>2</sub>eq per kg]. This is equivalent to 0.35% of the total footprint of the 60 kilograms of CO<sub>2</sub>eq per kilogram of beef. </p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>If you buy from your local farmer – let’s assume you walk there, and have zero transport emissions – your beef footprint is 59.8 kilograms CO<sub>2</sub>eq per kilogram [we calculate this as 60kg - 0.2kg]. It makes almost no difference.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Especially for foods with a large footprint, transport as a share of the food’s total emissions is fairly insensitive to the distance travelled. </p> <!-- /wp:paragraph --> <!-- /wp:owid/additional-information --> <!-- wp:paragraph --> <p>In a study published in <em>Environmental Science & Technology, </em>Christopher Weber and Scott Matthews (2008) investigated the relative climate impact of food miles and food choices in households in the US.{ref}Weber, C. L., & Matthews, H. S. (2008). <a href="https://pubs.acs.org/doi/abs/10.1021/es702969f">Food-miles and the relative climate impacts of food choices in the United States</a>. <em>Environmental Science & Technology</em>.{/ref} Their analysis showed that substituting less than one day per week’s worth of calories from beef and dairy products to chicken, fish, eggs, or a plant-based alternative reduces GHG emissions more than buying <em>all</em> your food from local sources.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>By analysing consumer expenditure data, the researchers estimated that the average American household’s food emissions were around 8 tonnes of CO<sub>2</sub>eq per year. Food transport accounted for only 5% of this (0.4 tCO<sub>2</sub>eq).{ref}This figure is very similar to the previous estimates we looked at from Joseph Poore and Thomas Nemecek (2018) where transport accounted for 6% of emissions.{/ref} This means that if we were to take the case where we assume a household sources <em>all</em> of their food locally, the maximum reduction in their footprint would be 5%. This is an extreme example because in reality there would still be small transport emissions involved in transporting food from producers in your area.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>They estimated that if the average household substituted their calories from red meat and dairy to chicken, fish or eggs just one day per week they would save 0.3 tCO<sub>2</sub>eq. If they replaced it with plant-based alternatives they would save 0.46 tCO<sub>2</sub>eq. In other words, going ‘red meat and dairy-free’ (not totally meat-free) one day per week would achieve the same as having a diet with <em>zero</em> food miles.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>There are also a number of cases where eating locally might in fact <em>increase</em> emissions. In most countries, many foods can only be grown and harvested at certain times of the year. But consumers want them year-round. This gives us three options: import goods from countries where they are in-season; use energy-intensive production methods (such as greenhouses) to produce them year-round; or use refrigeration and other preservation methods to store them for several months. There are many examples of studies which show that importing often has a lower footprint.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Hospido et al. (2009) estimate that importing Spanish lettuce to the UK during winter months results in three to eight times lower emissions than producing it locally.{ref}Hospido, A., i Canals, L. M., McLaren, S., Truninger, M., Edwards-Jones, G., & Clift, R. (2009). <a href="https://link.springer.com/article/10.1007/s11367-009-0091-7">The role of seasonality in lettuce consumption: a case study of environmental and social aspects</a>. <em>The International Journal of Life Cycle Assessment</em>, <em>14</em>(5), 381-391.{/ref} The same applies for other foods: tomatoes produced in greenhouses in Sweden used 10 times as much energy as importing tomatoes from Southern Europe where they were in-season.{ref}Carlsson-Kanyama, A., Ekström, M. P., & Shanahan, H. (2003). <a href="https://www.sciencedirect.com/science/article/abs/pii/S0921800902002616">Food and life cycle energy inputs: consequences of diet and ways to increase efficiency</a>. <em>Ecological Economics</em>, 44(2-3), 293-307.{/ref}</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":4} --> <h4>Avoid the small share of foods that are air-freighted</h4> <!-- /wp:heading --> <!-- wp:paragraph --> <p>The impact of transport is small for most products, but there is one exception: those which travel by air.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Many believe that air-freight is more common than it actually is. Very little food is air-freighted; <a href="https://ourworldindata.org/grapher/share-food-miles-by-method">it accounts for</a> only 0.16% of food miles.{ref}'Food miles' are measured in tonne-kilometers which represents the transport of one tonne of goods by a given transport mode (road, rail, air, sea, inland waterways, pipeline etc.) over a distance of one kilometre. Poore & Nemecek (2018) report that of the 9.4 billion tonne-kilometers of <a href="https://ourworldindata.org/grapher/food-miles-by-transport">global food transport</a>, air-freight accounted for only 15 million. This works out at only <a href="https://ourworldindata.org/grapher/share-food-miles-by-method">0.16% of the total</a>; most foods are transported by boat.{/ref} But for the few products which are transported by air, the emissions can be very high: it emits 50 times more CO<sub>2</sub>eq than boat per tonne kilometer.{ref}Temperature-controlled transport by sea generates 23g CO<sub>2</sub>eq per tonne kilometer, whereas temperature controlled air transport generates 1130g CO<sub>2</sub>eq per tonne kilometer.{/ref}</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Many of the foods people assume to come by air are actually transported by boat – avocados and almonds are prime examples. Shipping one kilogram of avocados from Mexico to the United Kingdom would generate 0.21kg CO<sub>2</sub>eq in transport emissions.{ref}We get this footprint value as: [9000km * 0.023kg per tonne-kilometer / 1000 = 0.207kg CO<sub>2</sub>eq per kg].{/ref} This is only around 8% of avocados’ total footprint.{ref}The average footprint of avocados is around 2.5kg CO<sub>2</sub>eq per kg.{/ref} Even when shipped at great distances, its emissions are much less than locally-produced animal products.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Which foods are air-freighted? How do we know which products to avoid?</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>They tend to be foods which are highly perishable. This means they need to be eaten soon after they’ve been harvested. In this case, transport by boat is too slow, leaving air travel as the only feasible option.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Some fruit and vegetables tend to fall into this category. Asparagus, green beans and berries are common air-freighted goods. </p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>It is often hard for consumers to identify foods that have travelled by air because they’re rarely labeled as such. This makes them difficult to avoid. A general rule is to avoid foods that have a very short shelf-life <em>and</em> have traveled a long way (many labels have the country of ‘origin’ which helps with this). This is especially true for foods where there is a strong emphasis on ‘freshness’: for these products, transport speed is a priority.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>So, if you want to reduce the carbon footprint of your diet, avoid air-freighted foods where you can. But beyond this, you can have a larger difference by focusing on what you eat, rather than ‘eating local’. Eating less meat and dairy, or switching from ruminant meat to chicken, pork, or plant-based alternatives will reduce your footprint by much more.</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":4} --> <h4><em>More of our work on the environmental impacts of food...</em></h4> <!-- /wp:heading --> <!-- wp:owid/prominent-link {"title":"Less meat is nearly always better than sustainable meat, to reduce your carbon footprint","linkUrl":"https://ourworldindata.org/less-meat-or-sustainable-meat","mediaId":29926,"mediaUrl":"https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2.png","mediaAlt":"","className":"is-style-thin"} --> <!-- wp:paragraph --> <p>How does the carbon footprint of food compare when we look beyond global averages to differences across the world?</p> <!-- /wp:paragraph --> <!-- /wp:owid/prominent-link --> <!-- wp:owid/prominent-link {"title":"The carbon footprint of foods: are differences explained by the impacts of methane?","linkUrl":"https://ourworldindata.org/carbon-footprint-food-methane","mediaId":30425,"mediaUrl":"https://owid.cloud/app/uploads/2020/03/GHG-emissions-by-food-type-with-and-without-CH4.png","mediaAlt":"","className":"is-style-thin"} --> <!-- wp:paragraph --> <p></p> <!-- /wp:paragraph --> <!-- /wp:owid/prominent-link --> <!-- wp:owid/prominent-link {"title":"Cutting down forests: what are the drivers of deforestation?","linkUrl":"https://ourworldindata.org/what-are-drivers-deforestation","mediaId":40140,"mediaUrl":"https://owid.cloud/app/uploads/2021/02/deforestation-drivers-thumbnail-01.png","mediaAlt":"","className":"is-style-thin"} --> <!-- wp:paragraph --> <p></p> <!-- /wp:paragraph --> <!-- /wp:owid/prominent-link --> | {
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"text": "This is data from the largest meta-analysis of global food systems to date, published in ",
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"text": "by Joseph Poore and Thomas Nemecek (2018).",
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"text": " In this study, the authors looked at data across more than 38,000 commercial farms in 119 countries.{ref}Poore, J., & Nemecek, T. (2018). ",
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"url": "https://science.sciencemag.org/content/360/6392/987",
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"text": "Reducing food\u2019s environmental impacts through producers and consumers",
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"text": "In this comparison we look at the total GHG emissions per kilogram of food product. CO",
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"text": " is the most important GHG, but not the only one \u2013 agriculture is a large source of the greenhouse gases methane and nitrous oxide. To capture all GHG emissions from food production researchers therefore express them in kilograms of \u2018carbon dioxide equivalents\u2019. This metric takes account not just CO",
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"text": " but all greenhouse gases.{ref}To express all greenhouse gases in carbon dioxide equivalents (CO",
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"text": "-eq), they are each weighted by their ",
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"text": " (GWP) value. GWP measures the relative warming impact one molecule or unit mass of a greenhouse gas relative to carbon dioxide over a given timescale \u2013 usually over 100 years. For example, one tonne of methane would have 34 times the warming impact of tonne of carbon dioxide over a 100-year period. GWP100 values are used to combine greenhouse gases into a single metric of emissions called carbon dioxide equivalents (CO",
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"text": "e is then derived by multiplying the mass of emissions of a specific greenhouse gas by its equivalent GWP100 factor. The sum of all gases in their CO",
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"text": "e form provide a measure of total greenhouse gas emissions.{/ref}",
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"text": "The most important insight from this study: there are massive differences in the GHG emissions of different foods: producing a kilogram of beef emits 60 kilograms of greenhouse gases (CO",
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"text": "Overall, animal-based foods tend to have a higher footprint than plant-based. Lamb and cheese both emit more than 20 kilograms CO",
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"text": "-equivalents per kilogram. Poultry and pork have lower footprints but are still higher than most plant-based foods, at 6 and 7 kg CO",
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"text": "For most foods \u2013 and particularly the largest emitters \u2013 most GHG emissions result from land use change (shown in green), and from processes at the farm stage (brown). Farm-stage emissions include processes such as the application of fertilizers \u2013 both organic (\u201cmanure management\u201d) and synthetic; and enteric fermentation (the production of methane in the stomachs of cattle). Combined, land use and farm-stage emissions account for more than 80% of the footprint for most foods.",
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"text": "Transport is a small contributor to emissions. For most food products, it accounts for less than 10%, and it\u2019s much smaller for the largest GHG emitters. In beef from beef herds, it\u2019s 0.5%.",
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"text": "Not just transport, but all processes in the supply chain after the food left the farm \u2013 processing, transport, retail and packaging \u2013 mostly account for a small share of emissions.",
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"text": "This data shows that this is the case when we look at ",
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"text": " food products. But studies also shows that this holds true for actual ",
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"text": "; for example, researcher Vilma\u00a0Sandstr\u00f6m and colleagues ",
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"text": "studied the footprint of diets across the EU",
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"text": ". Food transport was responsible for only 6% of emissions, whilst dairy, meat and eggs accounted for 83%.{ref}Sandstr\u00f6m, V., Valin, H., Krisztin, T., Havl\u00edk, P., Herrero, M., & Kastner, T. (2018). ",
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"text": "Related content:",
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"text": "Eating local only slightly reduces your emissions",
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"text": "Eating local beef or lamb has many times the carbon footprint of most other foods. Whether they are grown locally or shipped from the other side of the world matters very little for total emissions.",
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"text": "Transport typically accounts for less than 1% of beef\u2019s GHG emissions: choosing to eat local has very minimal effects on its total footprint. You might think this figure is strongly dependent on where in the world you live, and how far your beef will have to travel, but in the \u2018dropdown box\u2019 below I work through an example to show why it doesn\u2019t make a lot of difference.",
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"text": "Whether you buy it from the farmer next door or from far away, it is not the location that makes the carbon footprint of your dinner large, but the fact that it is beef.",
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"text": "You might think this figure is strongly dependent on where in the world you live, and how far your beef will have to travel. If you live somewhere very remote you\u2019d assume this must be much, much larger than if your beef is produced by your local farmer. But the key point here is that the difference in transport figures is very small relative to the total footprint of beef.",
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"text": "Let\u2019s take the example of beef from a beef herd \u2013 the average footprint is approximately 60 kilograms of CO",
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"text": "eq per kilogram of beef. Let\u2019s compare the transport footprint of buying from your local farmer (who turns out to be your neighbor), versus someone in the UK buying beef from Central America (approximately 9000 kilometers away).",
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"text": "Transporting food by boat emits 23 grams of CO",
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"text": "eq per tonne of product per kilometer. To transport the 9000 kilometers from Central America to the UK therefore emits 0.207 kilograms CO",
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"text": "eq [9000km * 23g per tonne-kilometer / 1000 / 1000 = 0.207 kg CO",
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"text": "eq per kg]. This is equivalent to 0.35% of the total footprint of the 60 kilograms of CO",
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"text": "If you buy from your local farmer \u2013 let\u2019s assume you walk there, and have zero transport emissions \u2013 your beef footprint is 59.8 kilograms CO",
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"text": "eq per kilogram [we calculate this as 60kg - 0.2kg]. It makes almost no difference.",
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"text": "In a study published in ",
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"text": "Christopher Weber and Scott Matthews (2008) investigated the relative climate impact of food miles and food choices in households in the US.{ref}Weber, C. L., & Matthews, H. S. (2008). ",
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"text": ".{/ref} Their analysis showed that substituting less than one day per week\u2019s worth of calories from beef and dairy products to chicken, fish, eggs, or a plant-based alternative reduces GHG emissions more than buying ",
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"text": "By analysing consumer expenditure data, the researchers estimated that the average American household\u2019s food emissions were around 8 tonnes of CO",
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"text": "eq per year. Food transport accounted for only 5% of this (0.4 tCO",
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"text": "eq).{ref}This figure is very similar to the previous estimates we looked at from Joseph Poore and Thomas Nemecek (2018) where transport accounted for 6% of emissions.{/ref} This means that if we were to take the case where we assume a household sources ",
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"text": " of their food locally, the maximum reduction in their footprint would be 5%. This is an extreme example because in reality there would still be small transport emissions involved in transporting food from producers in your area.",
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"text": "They estimated that if the average household substituted their calories from red meat and dairy to chicken, fish or eggs just one day per week they would save 0.3 tCO",
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"text": "eq. If they replaced it with plant-based alternatives they would save 0.46\u00a0tCO",
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"text": "eq. In other words, going \u2018red meat and dairy-free\u2019 (not totally meat-free) one day per week would achieve the same as having a diet with ",
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"text": "There are also a number of cases where eating locally might in fact ",
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"text": " emissions. In most countries, many foods can only be grown and harvested at certain times of the year. But consumers want them year-round. This gives us three options: import goods from countries where they are in-season; use energy-intensive production methods (such as greenhouses) to produce them year-round; or use refrigeration and other preservation methods to store them for several months. There are many examples of studies which show that importing often has a lower footprint.",
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"text": "Hospido et al. (2009) estimate that importing Spanish lettuce to the UK during winter months results in three to eight times lower emissions than producing it locally.{ref}Hospido, A., i Canals, L. M., McLaren, S., Truninger, M., Edwards-Jones, G., & Clift, R. (2009). ",
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"text": "(5), 381-391.{/ref} The same applies for other foods: tomatoes produced in greenhouses in Sweden used 10 times as much energy as importing tomatoes from Southern Europe where they were in-season.{ref}Carlsson-Kanyama, A., Ekstr\u00f6m, M. P., & Shanahan, H. (2003). ",
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"text": ", 44(2-3), 293-307.{/ref}",
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"text": "Many believe that air-freight is more common than it actually is. Very little food is air-freighted; ",
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"text": " only 0.16% of food miles.{ref}'Food miles' are measured in tonne-kilometers which represents the transport of one tonne of goods by a given transport mode (road, rail, air, sea, inland waterways, pipeline etc.) over a distance of one kilometre. Poore & Nemecek (2018) report that of the 9.4 billion tonne-kilometers of ",
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"text": ", air-freight accounted for only 15 million. This works out at only ",
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"text": "; most foods are transported by boat.{/ref} But for the few products which are transported by air, the emissions can be very high: it emits 50 times more CO",
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"text": "eq than boat per tonne kilometer.{ref}Temperature-controlled transport by sea generates 23g CO",
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2020-01-24 06:20:24 | 2024-02-16 14:22:49 | 1eLz7uWtNKJXUoxzM7x8Q1WiHMxOxh3nwoi71wMq8hKY | [
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'Eat local' is a common recommendation to reduce the carbon footprint of your diet. But transport tends to account for a small share of greenhouse gas emissions. How does the impact of what you eat compare to where it's come from? | 2020-01-24 06:20:24 | 2023-06-05 10:04:30 | https://ourworldindata.org/wp-content/uploads/2020/02/Environmental-impact-of-food-by-life-cycle-stage.png | {} |
Our World in Data presents the empirical evidence on global development in entries dedicated to specific topics. This blog post draws on data and research discussed in our entry on the **[Environmental impacts of food](http://ourworldindata.org/environmental-impacts-of-food) ** and [**CO2 and Greenhouse Gas Emissions**](https://owid.cloud/co2-and-other-greenhouse-gas-emissions) . People across the world are becoming increasingly concerned about climate change: 8-in-10 people see climate change as a major threat to their country.{ref}The [2018 Pew Research Center Survey](https://www.pewresearch.org/fact-tank/2019/04/18/a-look-at-how-people-around-the-world-view-climate-change/) polled people across the world on global threats: in many countries more than 8-in-10 people said that climate change was a major threat to their country. Even in countries which showed less concern, a large percentage saw it as a major threat: 59% in the US said it was a serious threat. This was a marked increase in concern from similar polls conducted a few years earlier.{/ref} As I have shown [**before**](https://ourworldindata.org/food-ghg-emissions), food production is responsible for one-quarter of the world’s greenhouse gas emissions. There is rightly a growing awareness that our diet and food choices have a significant impact on our carbon ‘footprint’. What can you do to really reduce the carbon footprint of your breakfast, lunches, and dinner? ‘Eating local’ is a recommendation you hear often – even from prominent sources, [including the United Nations](https://twitter.com/UN/status/1188622911080415235?s=20). While it might make sense intuitively – after all, transport does lead to emissions – it is one of the most misguided pieces of advice. Eating locally would only have a significant impact if transport was responsible for a large share of food’s final carbon footprint. For most foods, this is _not_ the case. GHG emissions from transportation make up a very small amount of the emissions from food and what you eat is _far more_ important than where your food traveled from. ## Where do the emissions from our food come from? In the visualization we see GHG emissions from 29 different food products – from beef at the top to nuts at the bottom. For each product you can see from which stage in the supply chain its emissions originate. This extends from land use changes on the left, through to transport and packaging on the right. This is data from the largest meta-analysis of global food systems to date, published in _Science _by Joseph Poore and Thomas Nemecek (2018). In this study, the authors looked at data across more than 38,000 commercial farms in 119 countries.{ref}Poore, J., & Nemecek, T. (2018). [Reducing food’s environmental impacts through producers and consumers](https://science.sciencemag.org/content/360/6392/987). _Science_, 360(6392), 987-992.{/ref} In this comparison we look at the total GHG emissions per kilogram of food product. CO2 is the most important GHG, but not the only one – agriculture is a large source of the greenhouse gases methane and nitrous oxide. To capture all GHG emissions from food production researchers therefore express them in kilograms of ‘carbon dioxide equivalents’. This metric takes account not just CO2 but all greenhouse gases.{ref}To express all greenhouse gases in carbon dioxide equivalents (CO2-eq), they are each weighted by their [global warming potential](https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions#global-warming-potential-of-greenhouse-gases) (GWP) value. GWP measures the relative warming impact one molecule or unit mass of a greenhouse gas relative to carbon dioxide over a given timescale – usually over 100 years. For example, one tonne of methane would have 34 times the warming impact of tonne of carbon dioxide over a 100-year period. GWP100 values are used to combine greenhouse gases into a single metric of emissions called carbon dioxide equivalents (CO2e). CO2e is then derived by multiplying the mass of emissions of a specific greenhouse gas by its equivalent GWP100 factor. The sum of all gases in their CO2e form provide a measure of total greenhouse gas emissions.{/ref} The most important insight from this study: there are massive differences in the GHG emissions of different foods: producing a kilogram of beef emits 60 kilograms of greenhouse gases (CO2-equivalents). While peas emits just 1 kilogram per kg. Overall, animal-based foods tend to have a higher footprint than plant-based. Lamb and cheese both emit more than 20 kilograms CO2-equivalents per kilogram. Poultry and pork have lower footprints but are still higher than most plant-based foods, at 6 and 7 kg CO2-equivalents, respectively. For most foods – and particularly the largest emitters – most GHG emissions result from land use change (shown in green), and from processes at the farm stage (brown). Farm-stage emissions include processes such as the application of fertilizers – both organic (“manure management”) and synthetic; and enteric fermentation (the production of methane in the stomachs of cattle). Combined, land use and farm-stage emissions account for more than 80% of the footprint for most foods. Transport is a small contributor to emissions. For most food products, it accounts for less than 10%, and it’s much smaller for the largest GHG emitters. In beef from beef herds, it’s 0.5%. Not just transport, but all processes in the supply chain after the food left the farm – processing, transport, retail and packaging – mostly account for a small share of emissions. This data shows that this is the case when we look at _individual_ food products. But studies also shows that this holds true for actual _diets_; for example, researcher Vilma Sandström and colleagues [studied the footprint of diets across the EU](https://www.sciencedirect.com/science/article/pii/S2211912418300361). Food transport was responsible for only 6% of emissions, whilst dairy, meat and eggs accounted for 83%.{ref}Sandström, V., Valin, H., Krisztin, T., Havlík, P., Herrero, M., & Kastner, T. (2018). [The role of trade in the greenhouse gas footprints of EU diets](https://www.sciencedirect.com/science/article/pii/S2211912418300361). _Global Food Security_, 19, 48-55.{/ref} <Image filename="Environmental-impact-of-food-by-life-cycle-stage.png" alt=""/> ### Explore an interactive version of this chart and download the data Greenhouse gas emissions across the supply chain by food product. https://ourworldindata.org/grapher/food-emissions-supply-chain ##### Related content: ### How do carbon footprints compare <em>per gram of</em> protein? https://ourworldindata.org/environmental-impacts-of-food#carbon-footprint-of-food-products ### How do carbon footprints compare <em>per kilocalorie</em>? https://ourworldindata.org/environmental-impacts-of-food#carbon-footprint-of-food-products ### Beyond global averages: how do the emissions of food production compare across the world? https://ourworldindata.org/less-meat-or-sustainable-meat ## Eating local only slightly reduces your emissions Eating local beef or lamb has many times the carbon footprint of most other foods. Whether they are grown locally or shipped from the other side of the world matters very little for total emissions. Transport typically accounts for less than 1% of beef’s GHG emissions: choosing to eat local has very minimal effects on its total footprint. You might think this figure is strongly dependent on where in the world you live, and how far your beef will have to travel, but in the ‘dropdown box’ below I work through an example to show why it doesn’t make a lot of difference. Whether you buy it from the farmer next door or from far away, it is not the location that makes the carbon footprint of your dinner large, but the fact that it is beef. ## Additional information You might think this figure is strongly dependent on where in the world you live, and how far your beef will have to travel. If you live somewhere very remote you’d assume this must be much, much larger than if your beef is produced by your local farmer. But the key point here is that the difference in transport figures is very small relative to the total footprint of beef. Let’s take the example of beef from a beef herd – the average footprint is approximately 60 kilograms of CO2eq per kilogram of beef. Let’s compare the transport footprint of buying from your local farmer (who turns out to be your neighbor), versus someone in the UK buying beef from Central America (approximately 9000 kilometers away). Transporting food by boat emits 23 grams of CO2eq per tonne of product per kilometer. To transport the 9000 kilometers from Central America to the UK therefore emits 0.207 kilograms CO2eq [9000km * 23g per tonne-kilometer / 1000 / 1000 = 0.207 kg CO2eq per kg]. This is equivalent to 0.35% of the total footprint of the 60 kilograms of CO2eq per kilogram of beef. If you buy from your local farmer – let’s assume you walk there, and have zero transport emissions – your beef footprint is 59.8 kilograms CO2eq per kilogram [we calculate this as 60kg - 0.2kg]. It makes almost no difference. Especially for foods with a large footprint, transport as a share of the food’s total emissions is fairly insensitive to the distance travelled. In a study published in _Environmental Science & Technology, _Christopher Weber and Scott Matthews (2008) investigated the relative climate impact of food miles and food choices in households in the US.{ref}Weber, C. L., & Matthews, H. S. (2008). [Food-miles and the relative climate impacts of food choices in the United States](https://pubs.acs.org/doi/abs/10.1021/es702969f). _Environmental Science & Technology_.{/ref} Their analysis showed that substituting less than one day per week’s worth of calories from beef and dairy products to chicken, fish, eggs, or a plant-based alternative reduces GHG emissions more than buying _all_ your food from local sources. By analysing consumer expenditure data, the researchers estimated that the average American household’s food emissions were around 8 tonnes of CO2eq per year. Food transport accounted for only 5% of this (0.4 tCO2eq).{ref}This figure is very similar to the previous estimates we looked at from Joseph Poore and Thomas Nemecek (2018) where transport accounted for 6% of emissions.{/ref} This means that if we were to take the case where we assume a household sources _all_ of their food locally, the maximum reduction in their footprint would be 5%. This is an extreme example because in reality there would still be small transport emissions involved in transporting food from producers in your area. They estimated that if the average household substituted their calories from red meat and dairy to chicken, fish or eggs just one day per week they would save 0.3 tCO2eq. If they replaced it with plant-based alternatives they would save 0.46 tCO2eq. In other words, going ‘red meat and dairy-free’ (not totally meat-free) one day per week would achieve the same as having a diet with _zero_ food miles. There are also a number of cases where eating locally might in fact _increase_ emissions. In most countries, many foods can only be grown and harvested at certain times of the year. But consumers want them year-round. This gives us three options: import goods from countries where they are in-season; use energy-intensive production methods (such as greenhouses) to produce them year-round; or use refrigeration and other preservation methods to store them for several months. There are many examples of studies which show that importing often has a lower footprint. Hospido et al. (2009) estimate that importing Spanish lettuce to the UK during winter months results in three to eight times lower emissions than producing it locally.{ref}Hospido, A., i Canals, L. M., McLaren, S., Truninger, M., Edwards-Jones, G., & Clift, R. (2009). [The role of seasonality in lettuce consumption: a case study of environmental and social aspects](https://link.springer.com/article/10.1007/s11367-009-0091-7). _The International Journal of Life Cycle Assessment_, _14_(5), 381-391.{/ref} The same applies for other foods: tomatoes produced in greenhouses in Sweden used 10 times as much energy as importing tomatoes from Southern Europe where they were in-season.{ref}Carlsson-Kanyama, A., Ekström, M. P., & Shanahan, H. (2003). [Food and life cycle energy inputs: consequences of diet and ways to increase efficiency](https://www.sciencedirect.com/science/article/abs/pii/S0921800902002616). _Ecological Economics_, 44(2-3), 293-307.{/ref} ## Avoid the small share of foods that are air-freighted The impact of transport is small for most products, but there is one exception: those which travel by air. Many believe that air-freight is more common than it actually is. Very little food is air-freighted; [it accounts for](https://ourworldindata.org/grapher/share-food-miles-by-method) only 0.16% of food miles.{ref}'Food miles' are measured in tonne-kilometers which represents the transport of one tonne of goods by a given transport mode (road, rail, air, sea, inland waterways, pipeline etc.) over a distance of one kilometre. Poore & Nemecek (2018) report that of the 9.4 billion tonne-kilometers of [global food transport](https://ourworldindata.org/grapher/food-miles-by-transport), air-freight accounted for only 15 million. This works out at only [0.16% of the total](https://ourworldindata.org/grapher/share-food-miles-by-method); most foods are transported by boat.{/ref} But for the few products which are transported by air, the emissions can be very high: it emits 50 times more CO2eq than boat per tonne kilometer.{ref}Temperature-controlled transport by sea generates 23g CO2eq per tonne kilometer, whereas temperature controlled air transport generates 1130g CO2eq per tonne kilometer.{/ref} Many of the foods people assume to come by air are actually transported by boat – avocados and almonds are prime examples. Shipping one kilogram of avocados from Mexico to the United Kingdom would generate 0.21kg CO2eq in transport emissions.{ref}We get this footprint value as: [9000km * 0.023kg per tonne-kilometer / 1000 = 0.207kg CO2eq per kg].{/ref} This is only around 8% of avocados’ total footprint.{ref}The average footprint of avocados is around 2.5kg CO2eq per kg.{/ref} Even when shipped at great distances, its emissions are much less than locally-produced animal products. Which foods are air-freighted? How do we know which products to avoid? They tend to be foods which are highly perishable. This means they need to be eaten soon after they’ve been harvested. In this case, transport by boat is too slow, leaving air travel as the only feasible option. Some fruit and vegetables tend to fall into this category. Asparagus, green beans and berries are common air-freighted goods. It is often hard for consumers to identify foods that have travelled by air because they’re rarely labeled as such. This makes them difficult to avoid. A general rule is to avoid foods that have a very short shelf-life _and_ have traveled a long way (many labels have the country of ‘origin’ which helps with this). This is especially true for foods where there is a strong emphasis on ‘freshness’: for these products, transport speed is a priority. So, if you want to reduce the carbon footprint of your diet, avoid air-freighted foods where you can. But beyond this, you can have a larger difference by focusing on what you eat, rather than ‘eating local’. Eating less meat and dairy, or switching from ruminant meat to chicken, pork, or plant-based alternatives will reduce your footprint by much more. ## _More of our work on the environmental impacts of food..._ ### Less meat is nearly always better than sustainable meat, to reduce your carbon footprint How does the carbon footprint of food compare when we look beyond global averages to differences across the world? https://ourworldindata.org/less-meat-or-sustainable-meat ### The carbon footprint of foods: are differences explained by the impacts of methane? https://ourworldindata.org/carbon-footprint-food-methane ### Cutting down forests: what are the drivers of deforestation? https://ourworldindata.org/what-are-drivers-deforestation | {
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"rendered": "\n<div class=\"blog-info\">Our World in Data presents the empirical evidence on global development in entries dedicated to specific topics.<br>This blog post draws on data and research discussed in our entry on the <strong><a href=\"http://ourworldindata.org/environmental-impacts-of-food\" target=\"_blank\" rel=\"noopener noreferrer\">Environmental impacts of food</a> </strong>and <a href=\"https://owid.cloud/co2-and-other-greenhouse-gas-emissions\"><strong>CO<sub>2</sub> and Greenhouse Gas Emissions</strong></a>.</div>\n\n\n\n<p>People across the world are becoming increasingly concerned about climate change: 8-in-10 people see climate change as a major threat to their country.{ref}The <a href=\"https://www.pewresearch.org/fact-tank/2019/04/18/a-look-at-how-people-around-the-world-view-climate-change/\">2018 Pew Research Center Survey</a> polled people across the world on global threats: in many countries more than 8-in-10 people said that climate change was a major threat to their country. Even in countries which showed less concern, a large percentage saw it as a major threat: 59% in the US said it was a serious threat.<br><br>This was a marked increase in concern from similar polls conducted a few years earlier.{/ref}</p>\n\n\n\n<p>As I have shown <a href=\"https://ourworldindata.org/food-ghg-emissions\"><strong>before</strong></a>, food production is responsible for one-quarter of the world\u2019s greenhouse gas emissions.</p>\n\n\n\n<p>There is rightly a growing awareness that our diet and food choices have a significant impact on our carbon \u2018footprint\u2019. What can you do to really reduce the carbon footprint of your breakfast, lunches, and dinner?<br><br>\u2018Eating local\u2019 is a recommendation you hear often \u2013 even from prominent sources, <a href=\"https://twitter.com/UN/status/1188622911080415235?s=20\">including the United Nations</a>. While it might make sense intuitively \u2013 after all, transport does lead to emissions \u2013 it is one of the most misguided pieces of advice. </p>\n\n\n\n<p>Eating locally would only have a significant impact if transport was responsible for a large share of food\u2019s final carbon footprint. For most foods, this is <em>not</em> the case.</p>\n\n\n\n<p>GHG emissions from transportation make up a very small amount of the emissions from food and what you eat is <em>far more</em> important than where your food traveled from.</p>\n\n\n\n<h4>Where do the emissions from our food come from?</h4>\n\n\n\n<div class=\"wp-block-columns\">\n<div class=\"wp-block-column\">\n<p>In the visualization we see GHG emissions from 29 different food products \u2013 from beef at the top to nuts at the bottom.</p>\n\n\n\n<p>For each product you can see from which stage in the supply chain its emissions originate. This extends from land use changes on the left, through to transport and packaging on the right.</p>\n\n\n\n<p>This is data from the largest meta-analysis of global food systems to date, published in <em>Science </em>by Joseph Poore and Thomas Nemecek (2018).</p>\n\n\n\n<p> In this study, the authors looked at data across more than 38,000 commercial farms in 119 countries.{ref}Poore, J., & Nemecek, T. (2018). <a href=\"https://science.sciencemag.org/content/360/6392/987\">Reducing food\u2019s environmental impacts through producers and consumers</a>. <em>Science</em>, 360(6392), 987-992.{/ref} </p>\n\n\n\n<p>In this comparison we look at the total GHG emissions per kilogram of food product. CO<sub>2</sub> is the most important GHG, but not the only one \u2013 agriculture is a large source of the greenhouse gases methane and nitrous oxide. To capture all GHG emissions from food production researchers therefore express them in kilograms of \u2018carbon dioxide equivalents\u2019. This metric takes account not just CO<sub>2</sub> but all greenhouse gases.{ref}To express all greenhouse gases in carbon dioxide equivalents (CO<sub>2</sub>-eq), they are each weighted by their <a href=\"https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions#global-warming-potential-of-greenhouse-gases\">global warming potential</a> (GWP) value. GWP measures the relative warming impact one molecule or unit mass of a greenhouse gas relative to carbon dioxide over a given timescale \u2013 usually over 100 years. For example, one tonne of methane would have 34 times the warming impact of tonne of carbon dioxide over a 100-year period. GWP100 values are used to combine greenhouse gases into a single metric of emissions called carbon dioxide equivalents (CO<sub>2</sub>e). CO<sub>2</sub>e is then derived by multiplying the mass of emissions of a specific greenhouse gas by its equivalent GWP100 factor. The sum of all gases in their CO<sub>2</sub>e form provide a measure of total greenhouse gas emissions.{/ref}</p>\n\n\n\n<p>The most important insight from this study: there are massive differences in the GHG emissions of different foods: producing a kilogram of beef emits 60 kilograms of greenhouse gases (CO<sub>2</sub>-equivalents). While peas emits just 1 kilogram per kg.</p>\n\n\n\n<p>Overall, animal-based foods tend to have a higher footprint than plant-based. Lamb and cheese both emit more than 20 kilograms CO<sub>2</sub>-equivalents per kilogram. Poultry and pork have lower footprints but are still higher than most plant-based foods, at 6 and 7 kg CO<sub>2</sub>-equivalents, respectively.</p>\n\n\n\n<p>For most foods \u2013 and particularly the largest emitters \u2013 most GHG emissions result from land use change (shown in green), and from processes at the farm stage (brown). Farm-stage emissions include processes such as the application of fertilizers \u2013 both organic (\u201cmanure management\u201d) and synthetic; and enteric fermentation (the production of methane in the stomachs of cattle). Combined, land use and farm-stage emissions account for more than 80% of the footprint for most foods.</p>\n\n\n\n<p>Transport is a small contributor to emissions. For most food products, it accounts for less than 10%, and it\u2019s much smaller for the largest GHG emitters. In beef from beef herds, it\u2019s 0.5%.</p>\n\n\n\n<p>Not just transport, but all processes in the supply chain after the food left the farm \u2013 processing, transport, retail and packaging \u2013 mostly account for a small share of emissions.</p>\n\n\n\n<p>This data shows that this is the case when we look at <em>individual</em> food products. But studies also shows that this holds true for actual <em>diets</em>; for example, researcher Vilma\u00a0Sandstr\u00f6m and colleagues <a href=\"https://www.sciencedirect.com/science/article/pii/S2211912418300361\" target=\"_blank\" rel=\"noreferrer noopener\">studied the footprint of diets across the EU</a>. Food transport was responsible for only 6% of emissions, whilst dairy, meat and eggs accounted for 83%.{ref}Sandstr\u00f6m, V., Valin, H., Krisztin, T., Havl\u00edk, P., Herrero, M., & Kastner, T. (2018). <a href=\"https://www.sciencedirect.com/science/article/pii/S2211912418300361\" target=\"_blank\" rel=\"noreferrer noopener\">The role of trade in the greenhouse gas footprints of EU diets</a>. <em>Global Food Security</em>, 19, 48-55.{/ref}</p>\n</div>\n\n\n\n<div class=\"wp-block-column\">\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"612\" height=\"550\" src=\"https://owid.cloud/app/uploads/2020/02/Environmental-impact-of-food-by-life-cycle-stage-612x550.png\" alt=\"\" class=\"wp-image-29928\" srcset=\"https://owid.cloud/app/uploads/2020/02/Environmental-impact-of-food-by-life-cycle-stage-612x550.png 612w, https://owid.cloud/app/uploads/2020/02/Environmental-impact-of-food-by-life-cycle-stage-400x359.png 400w, https://owid.cloud/app/uploads/2020/02/Environmental-impact-of-food-by-life-cycle-stage-150x135.png 150w, https://owid.cloud/app/uploads/2020/02/Environmental-impact-of-food-by-life-cycle-stage-768x690.png 768w, https://owid.cloud/app/uploads/2020/02/Environmental-impact-of-food-by-life-cycle-stage-1536x1380.png 1536w, https://owid.cloud/app/uploads/2020/02/Environmental-impact-of-food-by-life-cycle-stage-2048x1840.png 2048w\" sizes=\"(max-width: 612px) 100vw, 612px\" /></figure>\n\n\n <block type=\"prominent-link\" style=\"is-style-thin\">\n <link-url>https://ourworldindata.org/grapher/food-emissions-supply-chain</link-url>\n <title>Explore an interactive version of this chart and download the data</title>\n <content>\n\n<p>Greenhouse gas emissions across the supply chain by food product.</p>\n\n</content>\n <figure></figure>\n </block>\n\n\n<h5>Related content:</h5>\n\n\n <block type=\"prominent-link\" style=\"is-style-thin\">\n <link-url>https://ourworldindata.org/environmental-impacts-of-food#carbon-footprint-of-food-products</link-url>\n <title>How do carbon footprints compare <em>per gram of</em> protein?</title>\n <content></content>\n <figure><img width=\"768\" height=\"1\" src=\"https://owid.cloud/app/uploads/2020/01/ghg-per-protein-poore.svg\" class=\"attachment-medium_large size-medium_large\" alt=\"\" loading=\"lazy\" height=\"600\" width=\"850\" /></figure>\n </block>\n\n <block type=\"prominent-link\" style=\"is-style-thin\">\n <link-url>https://ourworldindata.org/environmental-impacts-of-food#carbon-footprint-of-food-products</link-url>\n <title>How do carbon footprints compare <em>per kilocalorie</em>?</title>\n <content></content>\n <figure><img width=\"768\" height=\"1\" src=\"https://owid.cloud/app/uploads/2020/01/ghg-per-protein-poore.svg\" class=\"attachment-medium_large size-medium_large\" alt=\"\" loading=\"lazy\" height=\"600\" width=\"850\" /></figure>\n </block>\n\n <block type=\"prominent-link\" style=\"is-style-thin\">\n <link-url>https://ourworldindata.org/less-meat-or-sustainable-meat</link-url>\n <title>Beyond global averages: how do the emissions of food production compare across the world?</title>\n <content></content>\n <figure><img width=\"768\" height=\"749\" src=\"https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-768x749.png\" class=\"attachment-medium_large size-medium_large\" alt=\"\" loading=\"lazy\" srcset=\"https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-768x749.png 768w, https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-400x390.png 400w, https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-564x550.png 564w, https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-150x146.png 150w, https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-1536x1499.png 1536w, https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-2048x1998.png 2048w\" sizes=\"(max-width: 768px) 100vw, 768px\" /></figure>\n </block></div>\n</div>\n\n\n\n<h4>Eating local only slightly reduces your emissions</h4>\n\n\n\n<p>Eating local beef or lamb has many times the carbon footprint of most other foods. Whether they are grown locally or shipped from the other side of the world matters very little for total emissions.</p>\n\n\n\n<p>Transport typically accounts for less than 1% of beef\u2019s GHG emissions: choosing to eat local has very minimal effects on its total footprint. You might think this figure is strongly dependent on where in the world you live, and how far your beef will have to travel, but in the \u2018dropdown box\u2019 below I work through an example to show why it doesn\u2019t make a lot of difference.</p>\n\n\n\n<p>Whether you buy it from the farmer next door or from far away, it is not the location that makes the carbon footprint of your dinner large, but the fact that it is beef.</p>\n\n\n\t<block type=\"additional-information\" default-open=\"false\">\n\t\t<content>\n\n<h3>Example: how much does distance traveled impact the footprint of beef? </h3>\n\n\n\n<p>You might think this figure is strongly dependent on where in the world you live, and how far your beef will have to travel. If you live somewhere very remote you\u2019d assume this must be much, much larger than if your beef is produced by your local farmer. But the key point here is that the difference in transport figures is very small relative to the total footprint of beef.<br><br>Let\u2019s take the example of beef from a beef herd \u2013 the average footprint is approximately 60 kilograms of CO<sub>2</sub>eq per kilogram of beef. Let\u2019s compare the transport footprint of buying from your local farmer (who turns out to be your neighbor), versus someone in the UK buying beef from Central America (approximately 9000 kilometers away).<br><br>Transporting food by boat emits 23 grams of CO<sub>2</sub>eq per tonne of product per kilometer. To transport the 9000 kilometers from Central America to the UK therefore emits 0.207 kilograms CO<sub>2</sub>eq [9000km * 23g per tonne-kilometer / 1000 / 1000 = 0.207 kg CO<sub>2</sub>eq per kg]. This is equivalent to 0.35% of the total footprint of the 60 kilograms of CO<sub>2</sub>eq per kilogram of beef. </p>\n\n\n\n<p>If you buy from your local farmer \u2013 let\u2019s assume you walk there, and have zero transport emissions \u2013 your beef footprint is 59.8 kilograms CO<sub>2</sub>eq per kilogram [we calculate this as 60kg – 0.2kg]. It makes almost no difference.</p>\n\n\n\n<p>Especially for foods with a large footprint, transport as a share of the food\u2019s total emissions is fairly insensitive to the distance travelled. </p>\n\n</content>\n\t</block>\n\n\n<p>In a study published in <em>Environmental Science & Technology, </em>Christopher Weber and Scott Matthews (2008) investigated the relative climate impact of food miles and food choices in households in the US.{ref}Weber, C. L., & Matthews, H. S. (2008). <a href=\"https://pubs.acs.org/doi/abs/10.1021/es702969f\">Food-miles and the relative climate impacts of food choices in the United States</a>. <em>Environmental Science & Technology</em>.{/ref} Their analysis showed that substituting less than one day per week\u2019s worth of calories from beef and dairy products to chicken, fish, eggs, or a plant-based alternative reduces GHG emissions more than buying <em>all</em> your food from local sources.</p>\n\n\n\n<p>By analysing consumer expenditure data, the researchers estimated that the average American household\u2019s food emissions were around 8 tonnes of CO<sub>2</sub>eq per year. Food transport accounted for only 5% of this (0.4 tCO<sub>2</sub>eq).{ref}This figure is very similar to the previous estimates we looked at from Joseph Poore and Thomas Nemecek (2018) where transport accounted for 6% of emissions.{/ref} This means that if we were to take the case where we assume a household sources <em>all</em> of their food locally, the maximum reduction in their footprint would be 5%. This is an extreme example because in reality there would still be small transport emissions involved in transporting food from producers in your area.</p>\n\n\n\n<p>They estimated that if the average household substituted their calories from red meat and dairy to chicken, fish or eggs just one day per week they would save 0.3 tCO<sub>2</sub>eq. If they replaced it with plant-based alternatives they would save 0.46 tCO<sub>2</sub>eq. In other words, going \u2018red meat and dairy-free\u2019 (not totally meat-free) one day per week would achieve the same as having a diet with <em>zero</em> food miles.</p>\n\n\n\n<p>There are also a number of cases where eating locally might in fact <em>increase</em> emissions. In most countries, many foods can only be grown and harvested at certain times of the year. But consumers want them year-round. This gives us three options: import goods from countries where they are in-season; use energy-intensive production methods (such as greenhouses) to produce them year-round; or use refrigeration and other preservation methods to store them for several months. There are many examples of studies which show that importing often has a lower footprint.</p>\n\n\n\n<p>Hospido et al. (2009) estimate that importing Spanish lettuce to the UK during winter months results in three to eight times lower emissions than producing it locally.{ref}Hospido, A., i Canals, L. M., McLaren, S., Truninger, M., Edwards-Jones, G., & Clift, R. (2009). <a href=\"https://link.springer.com/article/10.1007/s11367-009-0091-7\">The role of seasonality in lettuce consumption: a case study of environmental and social aspects</a>. <em>The International Journal of Life Cycle Assessment</em>, <em>14</em>(5), 381-391.{/ref} The same applies for other foods: tomatoes produced in greenhouses in Sweden used 10 times as much energy as importing tomatoes from Southern Europe where they were in-season.{ref}Carlsson-Kanyama, A., Ekstr\u00f6m, M. P., & Shanahan, H. (2003). <a href=\"https://www.sciencedirect.com/science/article/abs/pii/S0921800902002616\">Food and life cycle energy inputs: consequences of diet and ways to increase efficiency</a>. <em>Ecological Economics</em>, 44(2-3), 293-307.{/ref}</p>\n\n\n\n<h4>Avoid the small share of foods that are air-freighted</h4>\n\n\n\n<p>The impact of transport is small for most products, but there is one exception: those which travel by air.</p>\n\n\n\n<p>Many believe that air-freight is more common than it actually is. Very little food is air-freighted; <a href=\"https://ourworldindata.org/grapher/share-food-miles-by-method\">it accounts for</a> only 0.16% of food miles.{ref}’Food miles’ are measured in tonne-kilometers which represents the transport of one tonne of goods by a given transport mode (road, rail, air, sea, inland waterways, pipeline etc.) over a distance of one kilometre. Poore & Nemecek (2018) report that of the 9.4 billion tonne-kilometers of <a href=\"https://ourworldindata.org/grapher/food-miles-by-transport\">global food transport</a>, air-freight accounted for only 15 million. This works out at only <a href=\"https://ourworldindata.org/grapher/share-food-miles-by-method\">0.16% of the total</a>; most foods are transported by boat.{/ref} But for the few products which are transported by air, the emissions can be very high: it emits 50 times more CO<sub>2</sub>eq than boat per tonne kilometer.{ref}Temperature-controlled transport by sea generates 23g CO<sub>2</sub>eq per tonne kilometer, whereas temperature controlled air transport generates 1130g CO<sub>2</sub>eq per tonne kilometer.{/ref}</p>\n\n\n\n<p>Many of the foods people assume to come by air are actually transported by boat \u2013 avocados and almonds are prime examples. Shipping one kilogram of avocados from Mexico to the United Kingdom would generate 0.21kg CO<sub>2</sub>eq in transport emissions.{ref}We get this footprint value as: [9000km * 0.023kg per tonne-kilometer / 1000 = 0.207kg CO<sub>2</sub>eq per kg].{/ref} This is only around 8% of avocados\u2019 total footprint.{ref}The average footprint of avocados is around 2.5kg CO<sub>2</sub>eq per kg.{/ref} Even when shipped at great distances, its emissions are much less than locally-produced animal products.</p>\n\n\n\n<p>Which foods are air-freighted? How do we know which products to avoid?</p>\n\n\n\n<p>They tend to be foods which are highly perishable. This means they need to be eaten soon after they\u2019ve been harvested. In this case, transport by boat is too slow, leaving air travel as the only feasible option.</p>\n\n\n\n<p>Some fruit and vegetables tend to fall into this category. Asparagus, green beans and berries are common air-freighted goods. </p>\n\n\n\n<p>It is often hard for consumers to identify foods that have travelled by air because they\u2019re rarely labeled as such. This makes them difficult to avoid. A general rule is to avoid foods that have a very short shelf-life <em>and</em> have traveled a long way (many labels have the country of \u2018origin\u2019 which helps with this). This is especially true for foods where there is a strong emphasis on \u2018freshness\u2019: for these products, transport speed is a priority.</p>\n\n\n\n<p>So, if you want to reduce the carbon footprint of your diet, avoid air-freighted foods where you can. But beyond this, you can have a larger difference by focusing on what you eat, rather than \u2018eating local\u2019. Eating less meat and dairy, or switching from ruminant meat to chicken, pork, or plant-based alternatives will reduce your footprint by much more.</p>\n\n\n\n<h4><em>More of our work on the environmental impacts of food…</em></h4>\n\n\n <block type=\"prominent-link\" style=\"is-style-thin\">\n <link-url>https://ourworldindata.org/less-meat-or-sustainable-meat</link-url>\n <title>Less meat is nearly always better than sustainable meat, to reduce your carbon footprint</title>\n <content>\n\n<p>How does the carbon footprint of food compare when we look beyond global averages to differences across the world?</p>\n\n</content>\n <figure><img width=\"768\" height=\"749\" src=\"https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-768x749.png\" class=\"attachment-medium_large size-medium_large\" alt=\"\" loading=\"lazy\" srcset=\"https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-768x749.png 768w, https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-400x390.png 400w, https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-564x550.png 564w, https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-150x146.png 150w, https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-1536x1499.png 1536w, https://owid.cloud/app/uploads/2020/02/Carbon-footprint-of-protein-foods-2-2048x1998.png 2048w\" sizes=\"(max-width: 768px) 100vw, 768px\" /></figure>\n </block>\n\n <block type=\"prominent-link\" style=\"is-style-thin\">\n <link-url>https://ourworldindata.org/carbon-footprint-food-methane</link-url>\n <title>The carbon footprint of foods: are differences explained by the impacts of methane?</title>\n <content>\n\n<p></p>\n\n</content>\n <figure><img width=\"768\" height=\"742\" src=\"https://owid.cloud/app/uploads/2020/03/GHG-emissions-by-food-type-with-and-without-CH4-768x742.png\" class=\"attachment-medium_large size-medium_large\" alt=\"\" loading=\"lazy\" srcset=\"https://owid.cloud/app/uploads/2020/03/GHG-emissions-by-food-type-with-and-without-CH4-768x742.png 768w, https://owid.cloud/app/uploads/2020/03/GHG-emissions-by-food-type-with-and-without-CH4-400x386.png 400w, https://owid.cloud/app/uploads/2020/03/GHG-emissions-by-food-type-with-and-without-CH4-570x550.png 570w, https://owid.cloud/app/uploads/2020/03/GHG-emissions-by-food-type-with-and-without-CH4-150x145.png 150w, https://owid.cloud/app/uploads/2020/03/GHG-emissions-by-food-type-with-and-without-CH4-1536x1483.png 1536w, https://owid.cloud/app/uploads/2020/03/GHG-emissions-by-food-type-with-and-without-CH4-2048x1978.png 2048w\" sizes=\"(max-width: 768px) 100vw, 768px\" /></figure>\n </block>\n\n <block type=\"prominent-link\" style=\"is-style-thin\">\n <link-url>https://ourworldindata.org/what-are-drivers-deforestation</link-url>\n <title>Cutting down forests: what are the drivers of deforestation?</title>\n <content>\n\n<p></p>\n\n</content>\n <figure><img width=\"768\" height=\"402\" src=\"https://owid.cloud/app/uploads/2021/02/deforestation-drivers-thumbnail-01-768x402.png\" class=\"attachment-medium_large size-medium_large\" alt=\"\" loading=\"lazy\" srcset=\"https://owid.cloud/app/uploads/2021/02/deforestation-drivers-thumbnail-01-768x402.png 768w, https://owid.cloud/app/uploads/2021/02/deforestation-drivers-thumbnail-01-400x209.png 400w, https://owid.cloud/app/uploads/2021/02/deforestation-drivers-thumbnail-01-800x419.png 800w, https://owid.cloud/app/uploads/2021/02/deforestation-drivers-thumbnail-01-150x79.png 150w, https://owid.cloud/app/uploads/2021/02/deforestation-drivers-thumbnail-01.png 1200w\" sizes=\"(max-width: 768px) 100vw, 768px\" /></figure>\n </block>",
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"rendered": "‘Eat local’ is a common recommendation to reduce the carbon footprint of your diet. But transport tends to account for a small share of greenhouse gas emissions. How does the impact of what you eat compare to where it’s come from? ",
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"date_gmt": "2020-01-24T06:20:24",
"modified": "2023-06-05T11:04:30",
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"authors_name": [
"Hannah Ritchie"
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"modified_gmt": "2023-06-05T10:04:30",
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