What actually makes avocados bad for the environment?

The soaring demand for avocados in Europe and North America has led to a trebling of global production in just over 20 years. However, this popular fruit is increasingly controversial because of the environmental impacts of farming and distributing them around the world.

These issues are not inherent to avocados themselves, which could still be a part of a sustainable, healthy diet. But rather they reflect some of the deep-rooted problems associated with their production.

Avocados are native to Central and South America, where the warm, temperate climate provides ideal growing conditions. There are hundreds of varieties, however the one that most of us are familiar with today is the Hass variety, which can be traced back to a single tree planted almost 100 years ago.

Part of the avocado's rise in popularity over recent decades has come from its marketing as a "superfood." While some health claims may have been overstated, they are indeed a good source of vitamins, minerals and unsaturated fats, which give them their satisfying, creamy texture.

So why have avocados become so controversial? Like a lot of modern agriculture, most avocado plantations rely heavily on fertilizer and fossil fuels, contributing to rising greenhouse gas emissions. They have smaller yields than a lot of other crops and so have a higher carbon footprint per kilogram of fruit.

On average, avocados have a carbon footprint of around 2.5kg of CO₂ equivalent (kg CO₂e) per kg—that's all the greenhouse gases resulting from producing and transporting avocados, such as carbon dioxide, methane and nitrous oxide, rolled into the CO₂ equivalent of warming.

The carbon footprint of avocados is more than twice as high as bananas (0.9kg CO₂e per kg) and over five times higher than apples (0.4kg CO₂e per kg), although it is only slightly worse than tomatoes (2kg CO₂e per kg).

But these figures are small compared to the global average carbon footprint of most animal-derived products. A kilogram of eggs has a carbon footprint of 4.6kg CO₂e, a kilogram of chicken comes in at 9.8kg CO₂e, and a kilogram of beef results in a whopping 85kg CO₂e on average.

For those outside the Americas, the large distances avocados often travel may not be as big a deal as is commonly believed, at least in carbon terms. The vast majority of avocados are shipped, which is relatively low carbon because of the huge quantities that can be transported in a single voyage. Even when they are transported thousands of miles, shipping results in just 0.2kg CO₂e per kg of avocados, which is often much less than the footprint from growing them.

Shipping does entail other issues. Over-reliance on shipping has created a food system that is vulnerable to shocks and disruptions, where logjams and logistical bottlenecks (for example, the blockage of the Suez canal by a container ship in 2021), famines or wars in one part of the world can lead to disruptions or food shortages in many other countries.

The problem is likely to increase as the climate crisis deepens. This issue is not unique to avocados, but moving towards more locally supplied foods may build more resiliency and help protect against future food shortages.