Over 10,000 years ago, we planted our first seeds and domesticated animals – marking a major milestone for homo sapiens (humans).

Fast forward to the present and it’s easy to see that we’ve come a long way from founding agricultural practices to the complex globalised food system we’ve built today.  

Many of us are now able to purchase foods, in and out of season, throughout the year. Food systems tend to be high-yielding and complex: the low cost of the products could be argued to be offset by the hefty environmental cost.  

Is eating locally sourced food better for the planet? 

We are exploring the public discourse between local and non-local foods, through the lens of carbon emissions. 

But first, we need to understand the components of the food system.  

What’s the environmental cost of the food on my plate? 

The food on our plates often makes its way to us through a complex food system.  

What is a food system?  

A food system refers to the entire process (aka lifecycle) of producing, processing, distributing and consuming food.

This system accounts for a third, or 18 GTCO₂eq, of all greenhouse gas (GHG) emissions where: 

– Agricultural production (farms and animal feed) is responsible for a whopping 39% of the emissions. 

– Changes in land use (deforestation and fluctuations in carbon in soil) is responsible for 32% of the emissions and, 

– Other supply chain activities (like processing, transport, retail, packaging, and consumption) are responsible for 29% of the emissions.  

Aside from emissions, food systems are also accountable for high water usage and being the primary driver of biodiversity loss.

Evidently, the systems we’ve built need transformative changes that minimise this environmental toll. It also means addressing the undeniable role of the meat and dairy industry in the rise of emissions. 

From a consumer perspective, many argue that buying local produce is the best way to minimise our emissions.

Although this is a popular policy recommendation, academia suggests a slightly different picture. 

What does “locally sourced” food mean? 

There is no widely accepted definition of ‘local’ food, but it broadly revolves around minimal distances between where the food is produced and where it is consumed.  

‘Local’ food can be interpreted in a few ways:

– Within a community, city, village, or county, 
– Within a State (like in US, India), or, 
– Within a small country (like Jamaica, Estonia, Lebanon) 

In the US, according to the 2008 Farm Act, to be classified as ‘local’, foods would have to come from 400 miles or less.

If we apply this to a person shopping in Slovenia, a small European country, they could, in theory, buy produce from all their neighbouring countries and consider that as ‘local’.

So, the different interpretations to ‘local’ food allows room for varying circumstances.  

Does the type of transport used for foods matter? 

Yes! It is worth noting the emission disparities between different modes of transport.

The most GHG-efficient option for transporting food is via cargo ships. This is followed by rail, cars, vans, and trucks.

Unintuitively, storing foods locally year-round tend to be more GHG intensive than having the same products shipped from another country.   

In general, air freighted foods are the least GHG-efficient. As a consumer, it can be difficult to assess what is air-freighted and what is not.

A useful guide is to assess whether the product has a limited shelf life (for example, mangoes and berries) and if it is from a country quite far away.  

Now, let’s dive into a common question encountered in the local vs non-local food debate.  

Don’t non-locally sourced foods mean higher travel emissions? 

Not necessarily.

Here are eight foods and their supply chain emissions visualised in two ways: 

In figure 1, we are able to see the overall emissions of certain foods, noting that some foods have high emissions (like meat) while some have low or negative emissions (like nuts). Therefore, we can make the biggest impact by swapping out high-emission foods where possible.  

Figure 2 allows for a deeper understanding of emissions from each step of the supply chain. Although there are exceptions, travel emissions for most foods are minimal compared to the emissions associated with land use, farming, and animal feed. 

If you’d like to learn more about this in the context of other foods, click here to use the graphing tool. 

What are the best practices to adopt when sourcing foods? 

From an environmental perspective, making decisions on how to source foods can be unclear.

Some of the best practices guided by growing evidence suggests the following:  

– In terms of emissions reduction, what you eat matters more than whether it is local or not.  

– In general, buy locally grown seasonal foods like vegetables and fruits.  

– Buy local especially if you know where you’re buying from, who you’re buying from and how they grow the food. The transparency of supply chains will enable you to consider wider environmental, economic, and social impacts to make well-informed decisions. 

Everything you need to know about mangrove trees:

Mangroves are the only forests situated at the confluence of land and sea in the world’s subtropics and tropics. They have been variously described as “coastal woodland”, “mangal”, “tidal forest” and “mangrove forest.”  

There are roughly 70 species of mangrove trees occupying a total estimated area of 147,000 km² worldwide. This is equivalent to the size of Bangladesh! Roughly 43% of the world’s mangrove forests are situated in just four countries: Indonesia, Australia, Brazil, and Nigeria.  

These forests are home to an abundance of life, protecting people from floods whilst storing carbon at an impressive capacity. 

Biodiversity in mangrove forests 

In the right conditions, mangroves form extensive and productive forests.

These forests support animal populations both within the forest and in offshore areas. Densities of crabs are especially likely to be highest on unvegetated mudbanks adjacent to mangroves, feeding on propagules (buds of plants). 

Juvenile shrimps are important organisms near mangroves too, and a sought-after food for many communities. These shrimps obtain carbon (food) from plankton and algae living amongst the mangroves. 

There are also a few endemic mammal species in mangroves. For example, crab-eating rats in Australia, the leaf monkey in Malaysia, and the proboscis monkey in Borneo. 

Here is a diagram further highlighting the importance of mangroves to so many species for different reasons – 

Figure 1 Conceptual diagram illustrating the critical habitat that mangroves provide for a variety of animals [Credit: Integration and Application Network, University of Maryland Center for Environmental Science] 

Why should we care about mangrove trees? 

– Mangrove forests are widely recognised as providing a wide variety of goods and services to people, including protection from floods, provision of a variety of plant and animal products, sediment trapping, and nutrient uptake and transformation.  

– Annually, mangroves are responsible for over $60 billion in avoided losses from coastal flooding, protecting more than 15 million people.  

– An impressive diversity of plant products is harvested from mangrove trees, including tannins, honey, medicinal products, and thatch. 

Mangroves are a blue carbon solution  

– Mangroves have gained a lot of attention in recent years over their ability to sequester carbon, storing between 3-5 times more carbon per hectare than terrestrial forests. 

– They have carbon-rich soil that’s been built-up for over hundreds or thousands of years. 

– 87% of carbon stocks in mangroves are just within the top meter of soil. According to one report, if this were released into the atmosphere, it would be equal to 7.5 years of emissions from the EU or burning 51 billion barrels of oil. 

What are the drivers of degradation and loss of mangroves?  

Up to 60% of mangrove tree losses are due to direct or indirect human impacts. These drivers are –

– Logging (for timber, charcoal) 
– Agriculture (oil palm cultivation)
– Aquaculture (ponds for shrimp and fish farming) 
– Pollution (from oil and gas extraction, and nutrient run-off) 
– Coastal infrastructure development  
– Climate change (sea level rise, hurricanes, drought) 

Mangrove Restoration and Conservation Efforts 

Our knowledge of mangrove area dynamics at local to global scales has increased significantly since 2000 due to advances in remote sensing and data access.

Around 42% of remaining mangroves are now located in protected areas. But protected areas may not always provide strong protection. Many mangroves fall prey to erosion and storms, naturally occurring phenomena, while some don’t stand the test of time due to ineffective management.  

The front line of mangrove protection, management and sustainable use involves people—communities, indigenous groups, traditional users, and local governments.  

The Global Mangrove Alliance, is an important and ambitious initiative, seeking to halt loss caused by direct human impact, restore at least half of recent mangrove losses, and increase protection from over 40% to 80% by 2030. 

How coastal communities have helped mangrove forests thrive 

Around the world, there are countless examples of collaborations that have helped coastal communities and mangroves to thrive together.  

For example, in Pakistan, mangroves are concentrated mainly in the north along the Arabian Sea coastline where arid climate prevails. Under the Ten Billion Tree Tsunami Project, 43.50 million plants will be planted in one of the world’s largest endeavours to restore mangroves.  

This ambitious project will not only provide a natural barrier against erosion, climate disasters but will also restore breeding grounds for finfish and shrimps. It has the potential to improve the livelihoods of fishing and herding communities living in the many coastal villages dotting the country’s northern shores.   

Mangrove planting has been increasingly considered a Nature-based Solution (NbS)  

This enthusiasm, seen through national policy commitments and community-led initiatives, can now be assessed against a Global Standard for NbS, a criteria set by the International Union for Conservation of Nature (IUCN) to ensure that these projects are credible and well-designed to maximise their full potential.  

Mangroves provide many benefits and their ability to store carbon cannot be ignored. It is a useful nature-based solution to help reduce our emissions but it’s not the only one! 

What can I do to further mangrove conservation? 

1. Show your support for mangroves in native areas –
   Find out if mangroves are native to your surroundings. If they are, vocalise your support for them and educate your community on the importance of mangroves.
   
   If your local mangroves are subject to degradation, rally support for preservation and speak to your local authorities. You can also keep track of mangrove restoration through the Mangrove Restoration Tracker tool.  
    

2. Be a considerate tourist –
   Mangrove tourism exists across 93 countries, with boating being the most popular activity. So next time you travel, appreciate mangroves and the diverse wildlife they host but don’t leave anything behind!
   
   You can also participate in mangrove planting, for example, in the Philippines, through the Planeterra Project.