April: The month of local produce

Summary

This month has surprised us a little because we thought we would find more evidence that eating local produce would be the most ecologically beneficial option. Instead, what we eat is likely more important. It was evident though that eating locally grown foods can certainly benefit the community most and reconnect us all with our environment. This may be a big enough benefit because this reconnection gives us all the more reason to nurture our space. We failed to eat entirely local. I still had coffee for instance (and our bush was able to provide just one cup this year).

We donated to Rainforest 4 Foundation given that aggriculture is a clear driver of habitat clearing and their efforts are trying to save space for old forests.

Take homes

Our system is reliant on international trade. It is very difficult to source all our food locally. This is good and bad: it can buffer us all against crises by ensuring secure places can provide for others as needed, but it means we are reliant on faraway producers.

The jury is out on whether eating local is most environmentally protective. It can be for some of us and there is a great joy in growing foods ourselves to share locally, it can also benefit the community. What we eat is clearly critical for ecological health.

Top tips

Some information from the International Energy Agency on emissions from transportation is here

How to make your own compost tips can be found here:

A blog

A video

Some recommended podcasts on these subjects:

On environmental law

On sustainability

On food

(we have not listened to all of these yet! But... hope they are good)

To dos

Switching to a plant-based diet and / or minimising animal source foods, and choosing foods from low impact farms, are environmental wins.
Avoid any food that has been transported by plane.
Minimise consumer emissions through walking or cycling to buy foods when possible, or bulk buying to reduce the number of journeys made
Avoid heavily packaged and processed foods to reduce environmental costss from waste and transit.
Avoid wasting food, use composts if available and try not to bin any biodegradables.

Out of our hands

Most things to do with sourcing our foods is out of our hands... this is quite unsettling. Our system means we tend to be focused on our careers and trust that food is good to go when we purchase it. We tend not to ask questions like: What chemicals are used? How are foods processed? Is there any leaching from packaging? What health and environmental concerns are associated to food production? Region specific legislation regulates the food trade and some monitoring goes on. Trade agreements respect the rights of each location to make decisions on these concerns. Researching where our food comes from and how it is produced gives us at least a little reassurance when choosing what to eat.

April: The month of local produce

Food has become a commodity as much as anything else in our world. There is a social expectation to eat pretty much any types of harvest all year round, at least for those priviliged enough to afford choice. Food prices often do not match up the effort or risk taken on by producers. Growing your own veggies, herbs and fruits lifts a veil on how much we should be valuing food. It takes time, commitment to watering and a bit of good luck with rains and sun. With an aim to satiate the consumer - and feed large populations in lands less able to grow their own - all sorts of trade deals have struck up globally between different governments. This shapes the market to ship or fly food around the world, and even to grow it in one country, fly it elsewhere to be packaged, before shipping it out to other territories to sell.

This month, we will look into some of the reasons why people are advocating for returning to local produce. How does this makes sense from a sustainable environment perspective? What are some of the emissions costs of transporting food around the world? We will share the experience of the joys of growing your own. And look into some solutions being offered up to feed 10 billion people - the projected potential human population size for 2050.

April 6th: Why local?

An estimated 66 - 80 % of terrestrial space on our planet is reported to have been altered now by our actions (Riggio et al. 2020). There is a huge responsibility placed on governments and leaders to ensure access to food for their people. To achieve this, our world is now organised into sectors - e.g. urban expanses, rural space - leaving fragmented natural habitats among other zones. This segregation is a means to control provision of what we need efficiently and conveniently. It has it's ecological issues but it is where we are at.

The problem is, in geological terms, (and as noted in the book) globalisation has driven "extraordinarily rapid changes to our ecosystems and climate [...] at scale. [...] As we segregate diverse habitat, we also diminish Earth’s capacity to absorb the atmospheric shocks that will come with [...] rapid climate change."

The ecological reasoning for providing local food seems straight-forward. Land use change creates feedback loops with complex outcomes with generally negative impacts on ecosystems. Although, some people argue that it is more important to consider what we eat rather than where we source this food. A key example is that if we are eating beef, but the cattle raised in the nearby farm are fed with soya that is sourced from deforested zones in previously rainforested areas, our negative impact is greater than were we to eat the soya beans directly that are grown faraway.

We could create sustainable and resilient communities through the provision of locally produced foods that gift a variety of plant-based, affordable items. Of course, this means eating seasonal produce and potentially missing out on some foods altogether. This isn't ideal! Or it could mean investing in greenhouses, or even creating artificial biomes that could mimic climates most favourable to food crops.

How serious is the impact from trading foods around the world?

Probably the most worrying challenge is lost biodiversity due to our specific focus on the consumption of a very few livestock species. These few species (cattle and pigs, for example) now amass more than 93% of the total ruminant biomass on Earth (Bar-On, Phillips, and Milo 2018). Farming these livestock can have extreme impact by clearing land for pastures or for space to grow feed crops for these animals.

Equally, how we grow food is important. To feed so many people efficiently, we have used monoculture a lot historically. In an effort to bolster crop yields, tilling with heavy machinary may be used to turn the top soils and synthetic fertilisers are often applied to fields. Both actions reduce the living soil to very few species. When soils are healthy, they are full of life and, together, this complexity provides the nutrients needed for plants to grow well. By isolating single species crops, we hone in on specific compounds (like nitrogen and phosphorous) that are considered most important by applying synthetic fertiliser. In doing this, however, the natural regeneration process is decoupled so that species involved in the cycling of nutrients are lost. For some years this might mean certain crops thrive, but eventually, we see evidence of desertification. This is a term used to describe the severe degradation of land. At this point, yields diminish and the land loses its value.

A damaging cascade is unleashed as more carbon dioxide is released where vegetation cover is sparse, leading to further global warming. This last year (2021), we have witnessed severe drought in Kilifi, Kenya, with mass deaths of livestock across the once-green region as rains fail. Similarly, food production has been badly impacted in the US, Europe and China too.

Our farming communities across the world are witnessing the dramatic consequences from degraded habitats that include erosion (Shakesby, Doerr, and Walsh 2000; Begum 2021), accelerated leaching of nutrients, increased risk of contamination and reduced soil fertility (Wallach, Ben-Arie, and Graber 2005).

These issues are more about what we eat and how we produce it than where we source it. But trade deals exist between all countries. There are also the emissions costs linked to trading foods. In 2021, the UK was estimated to have imported £45,852 million while exporting £20,240 million in food, feed and drink (National Statistics, Chapter 14: The food industry, DEFRA). The strategy is partly to do with food security. The government reasons that sourcing a little bit from lots of places will buffer the country against catastrophe should it effect a particular place. About 46% of the UK's food is imported. About 80% of all the UK's food is sourced from the UK and Europe. The UK produced most of its grains domestically but only produced 16% of its fruit and about 50% of its vegetables. The remainder is sourced elsewhere. When it comes to fish, the UK imports most of what it eats and exports what it catches due to consumer choice. We can definitely impact this with our choices! For more, check out the information here.

Australia can grow all it needs and exports about 70% of what it produces. It continues to import too. The reason for this is also food security. Trade buffers countries against shocks should growing seasons fail for example. And there is lots more information for Australia here. There are likely inequalities though between which countries end up with enough to eat should there be global shortages. We will try and look more at this later on.

How can eating local produce help?

It seems like eating locally can help by lowering emissions costs from imported products. With a big enough shift, particularly for items that are equivalent when locally grown or imported (for instance, grains, meat and fish), the volume of shipping and air freight could be minimised. There are likely some complicated issues driven by trade agreements here that we can try and dig into later on. For instance, there might need to be some transitional support to protect the livelihood of a faraway producer who depends on the international market should we all rapidly decide to prioritise locally produced foods first.

Increasing a market for local producers could actually improve resilience during crises, if the crises impacts supply chains for example. Bringing food back toward local provision could also - hopefully - prevent further misuse of land that holds complex and distinct meanings and values for different communities elsewhere. It might encourage better care of the environment if we are reliant on it.

Growing our own food at home - no matter how small this contribution to our overall diet - makes me feel a bit safer than relying on imported foods. It is of course impossible to grow enough food for self sustainability for most of us but most of us could have a pot plant on the windowsill with basil, mint or watercress perhaps! It is also hugely rewarding to eat a fruit or veggie when it's homegrown... We are spoilt with the climate in Australia. Later, we will add a blog on our homegrowing experience.

So, on this opening ramble, I find that I am not yet sure whether eating local produce is the approach to green living that will have a large impact toward ecological resilience. Still, visiting farmers' markets and growing our own food is fabulous, so we will enjoy to this months challenge. Hope you do too (feel free to switch it to a late-Summer month if the climate suits better wherever you are living!

April 10th: Homegrown

One of the best things about living where we do is the climate. We can throw ourselves into growing foods. I am nearly 40 and this is the first place I have lived for long enough to start a balcony garden properly. I think this is probably the situation for many people. Renting in London meant that I moved often - mostly every 6 months or yearly. Now in Southeast Queensland, we are still renting but have a balcony and a communal garden into which we spill over for some guerrilla style planting. I am enjoying my 4th year here and my partner has been in the same place for nearly 8 years.

The first thing we did was set up a compost for the 12 units that make up the community block. About 3 households use it regularly and we dig it into the sandy soils whenever full. We have munched on pumpkins, tomatoes, many herbs, turmeric, citrus and paw paws among other favourites that have simply sprouted up from this resource. Most of our edibles are growing in pots - partly because the management of the garden includes the spraying of pesticides and weedkiller which we do not want to consume. Ironically, many largescale farms use these and the out of sight out of mind rules apply! But, for what we can enjoy here, we stick to our pot plants generally.

In this indulgent update, here are a bunch of our edibles and the tweaks we have found that make them grow best. I do not know if it applies elsewhere - please let us know if you try any out!

Pawpaw

Here, it is hard not to grow pawpaw (also known as papaya) if you throw the seeds out into a pot! It is a highly underrated freebie. But, you need to nurture up a few trees to make sure they will cross-pollinate to make the fruit. Pawpaw can be male or female trees. The males tend to have long flowers hanging out from the trunk. The females have flowers that stick right next to the trunk of the tree. We only need one male for a bunch of females. The females produce the fruit. The trees do better for us with richer soils - soils where we have mixed loads of compost with moss and some kind of mulch and that are months old so that the compost is well digested by all the microbes and fungi in the soils. These trees grow fast here and we have fruit coming on two trees now that are only a year or so old. We love the taste - especially bubba.

Rock melon and Cucumber

We got lucky with both rock melons and cucumbers this Summer. We have had about 20 cucumber from one plant and four melons. The vines for these look really similar, the cucumbers have slightly bigger leaves. They love the sunnier positions on the balcony. We have planted clovers, marigolds and lavender, poppies and desert rose inbetween crops which helps attract in the pollinators. We do not use any sprays and pick off caterpillers and beetles when we spot them and know that they are pests. We have a bunch of great mini beasts that we keep - spiders, preying mantis, assassin bugs, and ladybirds - these all eat the pests that tend to cause a problem. We have a few local friends to ask if any new beasties pop up and we do not know if they are beneficial or not so we are learning fast. These both need loads of water - my partner waters daily unless it rains.The fruit is delicious and well worth a few minutes each morning picking off unwanted bugs.

Passionfruit

Passionfruit is another favourite for us. We have grown six from seeds from the market fruit. In pots, we prepared soil quite carefully, layering in (bottom up) mulch - we have woody mulch, then compost from our leftovers that is decayed and rich, then a sphagnum moss to hold water, then some decent soil and finally some more mulch. We planted small shoots of about a metre into these pots and are getting flowers a year on. We tried planting into the sandier soil and the vine has taken much longer to establish, and into pots with unlayered soils and these also took a while to get going. It might just be a really good year in terms of rains and sun this year but all six plants are now flowering with a couple of fruit to boot!

Coffee

Possibly the favourite thing we have grown is coffee. We found a plant at a local cafe that has a brewing set up around the back, we picked a few beans and potted them up. It has taken four years but today we had a cup of coffee from our own bush... it was really tasty. I was stoked when the coffee seed came up until a local friend told me that coffee shrubs are basically weeds here! We found a bush last year and made a coffee from the beans from that one too but we think it got dug out recently - doh! The beans - or cherries - are reddish in colour. It is best to wait for them to be almost purple so the flavour is rich. We picked them and stored them in the freezer until enough had come through for about a cup. We peeled off the juicy red coats to find the beans within. Usually there are two per cherry. They have a harder case around them so we wiped off the sticky, juicy fruit and dried them in the sun. Then peeled off the casing. Once the bean is free we dried this too in the sun for another couple of days and then roasted them in a pan. We added agave after they had turned dark brown. Then we cooled them in the fridge which took away a bit of the stickiness from the agave. We ground them and enjoyed! Yummm... one coffee every few years is a bit minimal for me though so... we are a fair while from self-sustainability here!

Egg plant / Aubergine

We are lucky too with eggplant. We tried both the smaller and larger varieties (there are quite a few types I think) and had a good number from each plant. These are so tasty. I know you can grow them in the UK too as my brother was once gifted about 50 and came up with a whole bunch of recipes. My favourite (although I love eggplant simply roasted for hours with a little olive oil) is this:

Half the aubergine lengthways. Cross hatch without cutting the skin.

Prepare sauce: (Use about 50g of miso for a small aubergine)

Mix spring onions (one per aubergine), a chilli, a couple of garlic gloves diced with the miso sauce or a little soy sauce

Smear the sauce all over the aubergines

Bake for about an hour and a half or more at 200 degrees C or until the aubergine is soft.

Remake the sauce without the miso and with some soy sauce instread and pour this over to serve.

Enjoy!

Tomatoes and basil

Tomatoes and basil are a great combo in the pot or on the plate. These are edibles that it is possible to grow in many places. They need water and mulching a little bit to stop them drying out but are so tasty. I've read that tomatoes will fruit if a little stressed... so ours might be a bit tense! We get lots of fruit from these and have basil all year. We make a pesto from the basil and some kale or pak choi which we can grow too about once a week so it grows fast here and we just sprinkle the seeds around if the plant goes to seed. It smells great too.

Sweetcorn and green beans

We have tried corn a few times. This year was our most successful effort. We had grown some green beans in the pot prior to planting up sweetcorn. A little bit was still going. It definitely helped! This is a tip from more experienced gardeners but having tried it we like it. The legumes trap nitrogen in the soil that helps the corn. We have had a little success propagating sweetcorn from the previous plant. We just cut off the last 4 cm of the cob and replanted it. We have big dreams of self sustainability... one day... so all this playing is our preparation for that.

Turmeric

Turmeric has been one of the greatest freebies for us! It literally pops up wherever we have dug in some compost (that must include some of the discarded root from previous meals). It has a beautiful scent and the flowers are lovely - large unusual white and yellow bunches. A bonus of this plant is that it is likely a reasonable repellent of mosquitoes! This great article from colleagues Marta Ferreira Maia and Sarah Moore introduces many more mosquito repellent plants and herbs for those in need or interested!

Rosemary

We have a fantastic rosemary bush in the front of our unit here. We have donated quite a few offshoots to friends. It is easy to propagate. We just cut a few stems with recent growth and clear the lower leaves from the branch then stick them into healthy soils with lots of watering for the first week or so, some take. We add rosemary to loads of dishes these days and it tastes amazing. Definitely tasty with mushroons and squash!

April 16th: Free trade and the GDP

Understanding trade deals has never been straightforward for me. The major argument put forward for free trade and international markets is that these platforms connect people everywhere. This should - ideally - give all of us access to the same market allowing us to enjoy the economic benefits from the system. The well-intended ideal is that an international market levels wealth for people within and between countries with an intention to bring people out of poverty. However, generally, the data indicate that this is not playing out in reality.

In fact, studies suggest that inequalities between the rich and poor of society are expanding (Hodgson 2015; Bowles and Gintis 2002; Shorrocks, Davies, and Lluberas 2019). Although there are various strategies to address this (Ackerman and Alstott 1999), the World Inequality Report for 2022 states in the executive summary that:

"The poorest half of the global population barely owns any wealth at all, possessing just 2% of the total. In contrast, the richest 10% of the global population own 76% of all wealth. "

A blog on the pros and cons of freetrade can be found here. One of the summary take homes from this article is that freetrade agreements "can open new markets, increase gross domestic product (GDP), and invite new investments."

The GDP is a really critical metric for many governments today, it is "the total value of goods produced and services provided in a given time period" (as defined by the UK Parliament here), but is it one we should reform?

The ‘gross domestic product’ (GDP) is a metric that is used to measure economic growth. This GDP metric has four components:

business investment (any purchases that are required to produce consumer goods e.g. software, manufacturing equipment, new commercial or residential construction),
personal consumption (the money spent for personal use and enjoyment by individuals and households e.g. furniture, food and fuel; this article reports that in the US, personal consumption comprises 70% of the GDP!),
government spend (any public sector spending on goods and services e.g. education, health care and defence)
net exports (imports detract from the GDP while exports add to the metric estimate).

I feel a little nervous given the singular focus governments can sometimes have on growing their GDP. There are strange things that might be done to ensure the GDP grows, but that could cost the people of a country. For instance, encouraging consumerism could increase the GDP but cause a lot of material waste with ecological consequences. A commitment to building new homes - reportedly to help more people become home owners - would count as business investment, but this takes land from wildlife. (Often, there are enough houses, but it is the ownership of second homes or multiple homes standing empty that drives a demand for new ones - this is a tagential issue so will leave it here!) Or, trading out high quality food while importing poorer quality, cheaper alternatives, might mean a country increases their net exports (or decreases its trade deficit), but that people locally have poorer access to good nutrition and people and land internationally may be exploited to grow produce cheaply. If free trade agreements are used as a way to increase the GDP, by focusing on economic growth as measured by the GDP, we could be locking ourselves into production pathways that have high ecological and social costs. What could really help is a new metric for measuring governmental success that values ecological health and social wellbeing.

Food security is another big reason for free trade agreements. I understand this of course but as climate change plays out, I do wonder who is likely to have access to foods when stocks start falling short? The market is idealised to serve us - what we want - and we want access to this all the time. Consumer choice is somewhat driving what is imported into a country. But if we flip this idealogy around, we could instead look at the food markets as a means to protect ecology: what would we be able to access if we only used products that sustained ecologies - and protected the growers - what could we eat if we selected only those agricultural methods and food groups that protect the environment? Would we still have international trade as it stands? This is particularly interesting where we (humans) have altered the environment to focus on a particular crop. For instance, pumping groundwater out to irrigate fields. There is no resilience in these actions as we learned in the water month - we are simply draining the resource. As the climate becomes more chaotic with global warming, production in these locations will be interrupted. Perhaps environmental economists will find a solution. I will look at some of their thoughts and work next time!

April 21st: Environmental economics

The distance between growers and our plates means that there is space for issues to arise shuch as deforestation, groundwater overuse, exploitation of workers through underpay (or worse), an increase in single use plastic packaging to maintain freshness, and high transport emissions among other challenges. What can we do to entice the markets to support production of foods that do not cost the Earth? This is one of the key questions for environmental economics. What are our environmental and social values and what are we willing to trade off for produce affordability and availability?

The COVID-19 pandemic demonstrated the vulnerability of food supply systems in many territories including the UK and USA. People started to turn back to local farms to access foods, and producers had to find alternative markets as restaurants and other wholesale food venues were closed. Researchers Black and Duran reported the community changes in New London, Connecticut, that saw local people and farms teaming up to ensure food availabilty and funds for smallscale producers. The community economies witnessed placed greatest emphasis on well-being rather than profit. The authors write:

"This research demonstrates the ways in which local food systems are critical for resilience in the face of food insecurity and financial hardship. However, it also questions the sustainability of a way of producing and distributing food that often comes at the farmer’s expense, as governmental support for local food systems remains inadequate and food prices stay artificially low. When investigated further, attempts at achieving food system resilience reveal inequities that a highly subsidized industrial food system has created." (Black and Duran, 2023)

(There are other inspiring stories about people feeding those in need through allotments in the UK when crises strike.)

Ultimately, environmental economists are trying to address the market failures that result in environmental or social damage. There are 3 main tools: regulation through legal changes, social and peer driven incentives, and market-driven changes. A great introductory youtube video is here for anyone wanting to learn more specifics on environmental economics. Very briefly, environmental economists look for ways to change the system to drive legislation, policy or behaviours toward incentivising the market to change enough to acheive the desired ecololgical outcome. Ideally, for market-driven change, economists are looking for the magic mark where enough funding (through tax or caps) is made available to achieve affordable changes by business while minimal cost is inflicted to society.

How does food production change across producers globally?

One way to achieve a lower environmental impact is to compare the same products made and managed in different ways and adopt low impact options when possible. In 2018, researchers Poore and Nemecek looked at this in detail. One key finding they report comes down to what we eat - food produce from animals (as we now are all more familiar) was worse for the environment than plant-based foods. Meat pathways that were producing the lowest emissions still emitted more than most of the higher emitting plant-based foods - presenting a strong argument for us to change our diets. When it comes to food production, the stakes are high. Poore and Nemecek report that food production (from farm to consumer choice):

Creates approximately 32% of global terrestrial acidification and roughly 78% of eutrophication (check out our update on March 2nd for more on these processes).
Causes about 26% of human driven greenhouse gas emissions, with additional impacts from deforestation on top.
Uses roughly 37% of the world’s ice- and desert-free land.
And drives roughly 90 - 95% of our freshwater use.

These headlines are stark. Identifying within product differences can help and, perhaps, local produce has a key role. For beef production, for example (which is now relatively widely known to be the most expensive food in terms of the greenhouse gas emissions, amount of land and resources used), the range in greenhouse gas (GHG) emissions stretches from about 20 to 105 kg of CO2eq (carbon dioxide equivalents - a metric used for measuring how much carbon dioxide is emitted relative to its potential to contribute to global warming. The reference point is kept constant between food items so we can see the comparison) per 100 g of protein produced. For context, peas, nuts and other pulses score less than 5 kg of CO2eq per 100 g of protein. The study found that the area of land needed for this production is also highly variable for beef production, ranging from about 40 to 370 square-metres per year. This contrasted with peas that only required about 6 square metres per year at the maximum end of the range. The researchers are clear to point out that there are geographic differences in what is possible due to the general habitat and climate variability regionally. Mitigation will be specific for each producer, it is not the case that the best-performing farms (those with the lowest impact) can necessarily provide exact templates for others - though their knowledge will of course help.

Another interesting take home from the research is that there are trade-offs in how to reform producer habits to get the best outcome. The example given in the paper is that of Northern European barley farms. Barley has a relatively low environmental impact. Halving the space needed to grow the barley would reduce land use costs, but, to gain the same amount of protein from these smaller spaces, more intensive farming methods would be needed. This would produce greater GHG emissions and more acidification of the surrounding habitat. Poore and Nemecek (2018) tested some changes that have been put into play and found that

"only changing from monoculture to diversified cropping and improving degraded pasture [had substantial environmental benefits]."

Using local farmers' markets - where multiple smallholders who live within a relatively small geographic space have potential to grow diverse produce - might support environmentally sustainable food production. This enables a variety of crops to be produced in a relatively small space, for instance, if growers have a couple of hectares or less. Those selling at farmers' markets often have multiple products to cover different seasonal patterns too. The food miles are also low as a result. In addition to this, recent studies demonstrate the health benefits of eating a diverse array of plant-based foods (for more, here is a podcast interviewing Tim Spector, a scientist investigating diet and our health).

Have any regulations been put into play to help transition food production toward these environmental solutions?

Regulatory changes that can be made to shift the markets toward ecological protection. In their 2018 article, Poore and Nemecek point out that processors and retailers demand products meet certain standards, and because a small percentage of businesses supply a large proportion of the market (in the USA, just 10 retailers reportedly supply 52% of the grocery sales), producers are highly likely to adhere to regulatory changes so that they can access the market and sell their produce.

The EU states that

"a shift in our way of producing, buying and consuming food is necessary to improve the environmental footprint and help mitigate climate change, whilst protecting the livelihoods of all economic actors in the food chain, by generating fairer economic returns and opening up new business opportunities."

It has introduced a Farm to Fork Strategy to reach climate neutrality by 2050. For more information, check out this link with a summary video of the EU Parliament's aims.

More specifically, by 2030, the EU aims for:

"50% reduction in the use and risk of pesticides
at least 20% reduction in the use of fertilisers
50% reduction in sales of antimicrobials used for farmed animals and aquaculture
25% of agricultural land to be used for organic farming"

We can follow the progress of the legislation here as the Farm to Fork Strategy becomes law. The progress checker states that "A legislative proposal for a framework for a sustainable food system will be put forward before the end of 2023." So, watch this space!

April 27th: Is local better?

For the final update for April, I wanted to comment on whether choosing local produce is environmentally and socially better? Of course, my conclusion is - it depends... But, in researching for this update, I have found a few Take Homes that might be worth adopting.

Conveniently, I found this article that reviews "The Sustainability of "local" food" which is a great start. Reading this, I was not convinced on all the points raised but definitely found it useful. So, this update is a sort of conversation with the article by Stein and Santini (2022).

The conclusion on environmental sustainability from Stein and Santini (2022) is that:

"Local food cannot simply be equated with "sustainable food", in most cases, it neither can ensure food security nor does it necessarily have a lower carbon footprint."

The review raises that local food is considered sustainable due to low food miles keeping greenhouse emissions low. However, it counters that faraway farms may be able to reduce emissions costs from land use (presumably including fertiliser and pesticide application), production processes and storage to such as extent as to compensate for greater distance travelled by the products. If this is the case, it may well be possible for local producers to adopt practices that minimise their emissions and then provide local produce so reducing their footprint. So far, I am still an advocate for local food when possible, particularly when grown using low emission practices (for example, the minimal use or absence of fertiliser and pesticides to protect waterways and soils, diverse planting strategies to protect biodiversity and plant-based raw products to avoid processing and production costs). The review mentions the community benefits of growing foods locally and creating networks for provision, and this fits with our experience (of course, as a statistician I have to acknowledge the danger of falling into the trap of "What you see is all there is"! For more on this, I highly recommend reading Daniel Kahneman's "Thinking, Fast and Slow").

The review concludes strongly that consumer dietary choice is a greater influence than closeness to source. The evidence for this is fairly strong. Take Home 1: Switching to a plant-based diet and / or minimising animal source foods, and choosing foods from low impact farms, are environmental wins.

Next, the review raises the potential for economies of scale to tip the balance away from local produce. This is when the volume of product produced is so great that for each recipient of the food (the consumer), the total emissions to get a product from the farm to a consumer ends up being very small. For instance, if a cargo ship travels from Chile to Europe, it could emit 100 tonnes of CO2, but the ship could carry 1 million cans of a product, so that each can only costs 0.0001 tonnes to deliver plus the costs of a lorry - even an electric vehicle - transiting these to a supermarket (again gaining from economies of scale). If a local producer uses a less emissions-efficient vehicle and has to make loads of journeys to deliver the same volume of product, then the total cost per unit of food may be greater than the faraway producer.

The University College London has actually created an interactive map to track the emissions from ships! Check it out here. Shipping contributes about 2% of global GHG emissions annually. This is all shipping - not just food. There are big challenges ahead to decarbonise this transportation option (some being addressed, see here). Perhaps, were we able to transition to low carbon fuels as noted in the report from the IEA (International Energy Agency), the economies of scale could favour faraway low impact farms above local high-intensity or high impact ones. The review flags that freight transported by air will be far worse environmentally than local produce. Take Home 2: Avoid any food that has been transported by plane.

I am not entirely convinced by the economies of scale argument when producers are selling homegrown foods at local markets. There is not any need for packaging, and the travel costs for consumers would be relatively equivalent to picking up food from a supermarket. So, perhaps we could add a Take Home 3: Minimise consumer emissions through walking or cycling to buy foods when possible, or bulk buying to reduce the number of journeys made. This would be beneficial wherever the producers were based.

The review discusses how we farm. It raises the point that intensive farming might be required to produce enough food for the local demand but that this would cost environmentally. But also notes that locally produced goods would likely negate the need for packaging, reducing waste costs. Take Home 4: Avoid heavily packaged and processed foods to reduce environmental costss from waste and transit. Evidence is building too that processed foods are less healthy . An add-on to this is food waste. Methane emissions from land-filled food waste are huge. As a global population, the UN estimates we waste about 17% of our food (*This statistic comes from this article on UK foodwaste). When this ends up in landfill, the degradation process produces methane - a greenhouse gas. There is a blog here on food waste and methane emissions. So, Take Home 5: Avoid wasting food, use composts if available and try not to bin any biodegradables.

There is a huge base of literature on food production and the emissions costs from aggriculture. We will keep reading and see what else we comes up! Happy eating!