Supermarket shoppers buying avocados have been given an unwelcome message that the fruit is under threat and may be harder to come by in the future. Avocado-growing regions are shrinking due to the impact of climate change, meaning shoppers are facing potential shortages in the years to come.

The fruit is well known for its impact on the environment as it needs a lot of water to grow, which means it can put pressure on water supplies in areas that are water stressed. The best avocado growing regions include Mexico, Spain, South Africa, Peru and Chile, but volatile weather conditions in these areas are resulting in a decline in growth. It takes around 320 litres of water on average to grow a single avocado - four times the amount needed to produce a kilo of oranges and ten times that of tomatoes.

But because avocados need so much water to grow, it makes the fruit particularly vulnerable to climate change, particularly as the world is gradually becoming hotter, drier and more prone to drought. And when the weather turns hotter, this in turn makes growing conditions drier which can significantly slow avocado growth, leading to a drop in productivity - and ultimately less avocados on supermarket shelves.

According to a new report by Christian Aid, some of the best avocado growing regions are shrinking which is expected to result in a decline in avocado growth of 14%-41% by 2050.

The report states: “Avocados themselves are vulnerable to climate impacts. Their need for water means they can suffer in regions that are receiving less rainfall because of climate change. They also have heat tolerance limits that may be challenged with the increasing numbers of heatwaves being seen around the world. 

"Their growth and viability as a crop in the changing climate in the current major producing areas of Mexico, Spain, Chile, and Colombia is projected to shift. 

"Overall areas deemed highly suitable for growing avocados are expected to decline by 14-41% globally by 2050, depending on the climate scenario, but moderately suitable second tier areas will grow by only 12-20%5 . Avocado production may not be down and out with climate change, but this would cause major problems for current growers with many being put out of business."

Avocado farming puts a significant amount of pressure on water resources in dry regions, such as Mexico, and if conditions become drier due to climate change, this will have an adverse knock-on effect on avocado production.

The report adds: "Mexico, the world’s biggest producer, could see its potential growing area reduced by 31% by 2050 even if global average temperature rise was limited to under 2C. If temperatures rise by 5C, growing areas could reduce by 43%, endangering the industry’s sustainability and the livelihoods dependent on it."

But Zac Bard, chairman of the World Avocado Organisation, a non-profit organisation that represents avocado growers across the globe, says that the amount of water needed to grow avocados is actually much lower in wetter regions - and considerably less than the amount required to grow the likes of chocolate or coffee.

He explains: "Avocados have, unfortunately, been subject to negative press regarding their environmental impact, including unfounded claims often fueled by unrepresentative or little evidence. 

“To put things into perspective, one kilo of avocados needs an average of around 800 litres of water, but this can be much lower in wetter regions, where avocado trees can depend heavily on rainfall water. This is considerably less than what is needed for other household staples such as beef, coffee, and chocolate, which can be much greater.”