Local is not automatically lower carbon
It is easy to assume that food grown nearby must be better for the environment. Sometimes it is. But the distance food travels is only one part of its footprint, and for many foods it is a small part. In most analyses, how and where a food is produced tends to matter more than how far it travels afterwards. The relationship between distance and production method is looked at in more depth in the article on food miles, so only the key points are covered here.
Some examples of why local alone is not a reliable guide:
- Tomatoes grown in a heated greenhouse in a cold climate can use more energy than tomatoes grown outdoors in a sunny region and shipped in, depending on the fuel and the distance.
- Bulk transport by sea or rail is generally efficient per kilogram of food, while many small trips by car to collect produce can add up.
- Air freight is the major exception. A small amount of fresh produce is flown in, usually delicate, short-lived items, and this has a much higher transport footprint. Air freight is one part of the wider picture of flying emissions.
Because the details vary by product, country and season, any simple rule has exceptions. It is wise to treat claims that local food is always greener, or always worse, with caution.
What “seasonal” adds
Seasonal produce means fruit and vegetables eaten at the time of year when they grow naturally in your region. It can help the environment in a few ways:
- Less heated or lit growing. Out-of-season crops in cooler regions are often grown in heated or lit greenhouses, which can use a lot of energy.
- Less long-term storage. Some crops are kept in controlled cold stores for months, which takes energy, although for hardy crops such as apples, potatoes and onions storage is very efficient.
- Less pressure for air freight. Demand for fresh produce out of season is one reason some items are flown in.
Seasonal eating does not mean a monotonous diet. In many temperate regions, winter eating involves roots, cabbages, leeks, squash and stored apples, while summer brings salad crops, berries and tomatoes. Preserved foods such as frozen vegetables, jars and dried goods can fill gaps. Frozen vegetables are often picked and frozen soon after harvest, so they can be a good option in winter and may waste less than fresh items that spoil in the fridge.
Other reasons people buy local
Environmental impact is not the only reason to buy from nearby producers, and some of the reasons are worth treating separately:
- Freshness and taste. Produce picked recently and sold nearby can taste better, particularly soft fruit and leafy greens, though this is a matter of experience and varies.
- Supporting local farms. Buying direct from growers keeps more money in the local economy and may help small farms to continue. This is a social benefit, not necessarily an environmental one.
- Knowing your grower. At a market or farm shop you can ask questions about growing methods, pesticide use and variety.
- Connection to the seasons. Eating with the calendar helps people see how food is grown.
These are real benefits, but they should not be confused with a guaranteed lower carbon footprint.
When buying imported food is reasonable
Importing is not inherently bad. Some crops grow far more efficiently in warmer or wetter climates, so shipping them can be more efficient than growing them in a heated greenhouse at home. Tea, coffee, bananas and chocolate cannot be grown in many countries at all, and buying them supports farmers elsewhere. For these foods, the better questions concern farming practices, labour conditions and waste, not distance.
Practical ways to eat more seasonally
A few approaches that tend to work without much effort:
- Learn what grows in your region and when. Many countries publish seasonal food calendars, and local farm shops and markets often display what is in season.
- Look for origin labels. Check where produce comes from and, if you can, favour field-grown over heated-greenhouse produce when options exist.
- Join a box scheme or visit a market. These can introduce you to unfamiliar vegetables and reduce packaging, although they vary in how they are run.
- Preserve a glut. Freezing, pickling or making jam in the harvest season takes effort but extends the supply.
- Grow a little yourself. Even a few pots on a balcony count, and community gardens can offer a chance to grow in season.
- Store properly. Good produce storage reduces losses, which matter just as much as source.
Waste often matters more than origin
A lettuce that is grown nearby and then thrown away unused may have a larger footprint per portion eaten than one that was transported but eaten. Reducing food waste is therefore usually a more reliable step than choosing between local and imported. Similarly, what you eat generally has a bigger effect than where it comes from, which is why shifting toward a plant-based diet often matters more than whether a particular steak was produced down the road.
A sensible rule of thumb
If you want a simple approach, it might look like this:
- Prefer produce that is in season where you live.
- Be cautious of items that are highly perishable and out of season, particularly if they are flown in.
- Do not choose food on the word “local” alone. Look at the product, the season and the production method.
- Buy only what you expect to eat.
No rule is perfect, and the right answer can change from one product to the next. The aim is to make informed, reasonable choices rather than to chase an exact carbon figure for every meal.