Climate: The Orange Tree Zone Expands In France.

Gardening enthusiasts are well acquainted with the orange tree zone, which refers to the regions in France where citrus trees can be safely planted in the ground. Due to climate change, this area, once confined to a narrow coastal strip, is expanding. Unpacking a phenomenon that worries climatologists.

What is the orange zone?

In Europe, the term "orange zone" is used by analogy with the olive zone. This concept can be loosely defined as the Mediterranean climate area where citrus fruits can be grown in the ground. In these regions with mild climates, citrus trees not only thrive but also bear fruit on a perennial basis.

The United States Department of Agriculture or USDA defines "hardiness zones" more precisely, using a scale from 0 to 14 with subdivisions of 5°F designated by the letters a and b.

In the American system, the "orange zone," where citrus can regularly bear fruit, corresponds to zone 9b, with minimum temperatures ranging between -3.9°C and -1.1°C.

Where is the orange tree area located in France?

In France, the traditional area for orange trees corresponds to a narrow strip of land stretching between the eastern coasts of the Pyrenees and the French Riviera. Moreover, it is possible to grow oranges and lemons in other parts of the country that benefit from a microclimate.

Today, the citrus growing areas are changing due to climate change: whereas it was once unthinkable to cultivate citrus fruits outside the South, it is now possible to grow them in Gironde!

How is the orange tree area evolving in France?

Traditionally, citrus cultivation is concentrated in the south of Europe, in Spain, Italy, and Corsica with Sicilian lemons and Corsican clementines. In France, citrus fruits are a specialty of the French Riviera with the equally famous Menton lemon PGI.

However, in recent years, French citrus production has increasingly moved northward, to the point where oranges can now be grown in Gironde. According to experts, this expansion of the orange-growing zone is one of the symptoms of global warming. Climatologists talk about a "gradual tropicalization" of parts of France.

Even though we do not yet live under a tropical climate, changes are already noticeable, and farmers are on the front line facing risks of heatwaves, droughts, or conversely, floods.

How is climate going to impact agriculture in France?

In the future, fruit and vegetable production in France could be drastically altered due to rising temperatures. Although warming will not be uniform across the country and will not affect all sectors throughout the year, farmers should brace for crop losses.

An AXA Climate study, published in March 2023 in collaboration with the National Federation of Fruit Producers, estimates average production losses at 31% if warming continues according to the IPCC's intermediate scenario, with an average temperature increase of more than 1.5°C by 2030.

Based on the IPCC's most pessimistic scenario, up to 45% of production areas could face a "high" or "extreme" risk due to climatic hazards. To reach this conclusion, insurer AXA analyzed 16 types of produce across 25 French departments. The study focused on fruit production such as apples, blackcurrants, raspberries, blueberries, and redcurrants.

For example, it suggests that French farmers will have more difficulty growing blueberries and raspberries. With the expansion of the orange-growing zone, fruit producers may need to switch to cultivating citrus fruits, kiwis, or almonds…