Although it is (often) all red on our plates, the star of summer also fears sunburn. Local or imported from Morocco, Spain or Italy, tomatoes decorate French stalls all year round, shamelessly defying the rules of the seasons. But with global warming, tomatoes are becoming increasingly difficult to grow in southern Europe. Even in France, several studies suggest that we will have to adapt to continue growing them, in twenty, thirty or fifty years, like many other crops.
Tomatoes from the fields, greenhouses, small market gardeners or large producers, prepared in salads or sauces… All are in one way or another vulnerable to the vagaries of increasingly chaotic weather as the climate warms, under the effect of greenhouse gases emitted by human activities.
“Whatever the type of crop, the tomato is irrigated”explains François Lecompte, deputy director of the Plants and Horticultural Crop Systems laboratory at the National Institute for Agricultural, Food and Environmental Research (INRAE). Consequently, areas hit by repeated droughts are the most vulnerable, depending on whether or not they can count on the availability of water for irrigation. On the temperature side, “beyond 32-34°C, there are problems with fruit setting [passage de la fleur au fruit]risks of fruit burn and apical necrosis”, “continues the scientist, who also cites exposure to new parasites or diseases, or even pollinators stunned by the heat.
After a summer of 2022 marked by these hot and dry conditions, French production of tomatoes for the fresh market had thus decreased by 3% compared to 2021, despite a 7% increase in cultivated areas. “All production basins are affected, to varying degrees,” detailed the annual report of France Agrimer (PDF)recalling that the hotter it is, the more tomatoes the French consume. The following summer, it is the south of Europe that suffocates, from Greece to Spain. The production of these countries suffers to such an extent that in the summer of 2023, Spanish distributors turn to Belgian producers to fill their shelves, explained to the Flemish media VRT News the head of the Belgian cooperative BelOrta. “Germany also bought more tomatoes from us because they could no longer get them from Spanish growers”.
In Belgium, as in the Netherlands, all tomato production takes place in greenhouses. France, on the other hand, has a mixed model: a majority in greenhouses, intended for the consumption of fresh tomatoes, and a part in open fields, most of which is processed, into sauce, canned or even in our pizzas and ready meals. The latter, outdoors, are logically less protected from climatic hazards.
“Summer is gradually becoming hostile to tomatoes in Spain and the south of France. The Channel coasts, on the contrary, are acquiring significant potential”agroclimatologist Serge Zaka recently wrote on X,author of a study on the evolution of the “seasonality” and “biogeography” of this field tomato. A model for the years 2060-2090 shows that “L“The distribution area of the tomato tends to spread towards the North and disappear from the South with the progressive desertification of Spain.”
For the moment, French producers do not know “repeated problems of access to water” observed in other Mediterranean regions, rejoices the director of the interprofessional organization for tomatoes intended for processing (Sonito), Robert Giovinazzo. Three quarters of French production is done along the Rhone Valley, between Lyon and the Camargue delta, he explains. “Our irrigation capacities are not comparable with a region like Andalusia. For us to have no more water, there would have to be no more glaciers in the Alps to feed the Rhone.” Nevertheless, the resource is threatened, as the Alpine glaciers have lost 70% of their volume since 1850, and could even disappear by the end of this century, according to the IPCC’s most pessimistic scenario. (PDF).
While waiting for the number of conflicts of use to explode along the river that supplies cities, factories, fields and nuclear power plants, the producers of open-field tomatoes are working “in France as elsewhere to irrigation systems which allow better management of water supply, such as drip irrigation, or on “the possibility of developing photovoltaism”, that is, protecting crops with solar panels. Do they plan to eventually move up the Rhone Valley? “We are thinking about it. We are looking at it closely and we know that we will have to do it one day, but we are not in that situation yet.”supports the director of Sonito.
The ambition, for the moment, is to increase French cultivation of these tomatoes intended for processing, tiny in comparison with its neighbours. France produces between 160,000 and 180,000 tonnes per year, compared to almost 6 million tonnes in Italy and up to 3 million tonnes in Spain. “90% of tomatoes consumed in France come from abroad, including 85% from Italy and Spain”, Robert Giovinazzo further explains. Will France be able to compensate, in the longer term, for the difficulties of the South? Is there a risk of climate change, as the magazine feared in 2023? Time in view of the collapse of the gigantic Californian production, “threaten ketchup” ? The presidents of Sonito and the Provence-Alpes-Côte-d’Azur Chamber of Agriculture, André Bernard, aim in any case to increase the share of French tomatoes intended for processing consumed in France. From 10% today to 25% by 2030, via a strategy aimed in particular at integrating this open-field tomato with other crops.
Global warming is not only manifested through heat and drought. Floods, storms or even the chaotic alternation of dry periods and heavy rains mistreat crops and disarm the most seasoned farmers. Including the market gardeners who produce the tomatoes that we find on stalls. These are, unlike tomatoes destined to be processed, very largely grown in greenhouses, where heat, light and humidity can be regulated as desired.
A researcher at the Ecosys unit of INRAE, Kévin Morel, has worked for a long time on peri-urban market gardening in Ile-de-France: in regions less exposed to stifling summers, “There are more regular gusts of wind today, more frequent episodes of hail… Extreme conditions that can destroy a greenhouse,” he explains. “If we want to plan for the years to come, it is essential not to just look at the drought.” And this is even if the off-season offers new opportunities, like here, at a market gardener in Val-d’Oise capable, in 2022, of offering fresh tomatoes in October to his customers.
In the fall of 2023, in Brittany, storm Ciaran broke “almost 50 000 m2 of roofs” on the greenhouses of the Savéol cooperative, its president, Pierre-Yves Jestin, explained to AFP in April. Fortunately for the French tomato leader, “she just fell into the interculture”. But before that, the region that dominates the production of fresh tomatoes “lack of light, [les producteurs ont] struggled to catch up with the delays from spring. Farms have also been hit by viruses”he told AFP, citing production losses of “3,000 to 5,000 tons” over the year.
Growing crops under cover is not without risk, confirms Kévin Morel, noting however “that we should see more crops under cover in the future, in order to better control the conditions. But this raises the question of the energy cost”he insists. UA tonne of tomatoes grown in a heated greenhouse in France emits as much CO2 as a tonne of seasonal tomatoes transported by truck from South Africa, we explained in this article in our True or Fake section. “Are we going to continue to grow tomatoes in the middle of summer in Perpignan, whatever the cost, deploying a huge amount of energy to achieve this? Perhaps it is more relevant to follow the evolutions of the climate and grow tomatoes elsewhere during this season” even if it means doing it in the South in spring and autumn, continues the agronomist, before concluding: “If to adapt to climate change we start consuming more energy, then that is not the solution. It is maladaptation.”