Can the water war be avoided? While the available blue gold will become rarer in the summer in France due to climate change, the demand for water risks jumping if the current trend continues. Annual consumption could even double by the middle of the century, compared to the year 2020. This is one of the lessons of the new analysis note from France Stratégie, commissioned in the fall of 2023 by the former Prime Minister Elisabeth Borne and published this Monday, January 20.
“In order to anticipate possible conflicts of use, it is now essential to study the trajectories of changes in demand”explains the note from this autonomous institution attached to the Prime Minister. This prospective study therefore plunges us into the France of 2050 with three different scenarios, depending on the societal choices that will be made. The first possible path is the “trend”, that is, it continues the current trend, without additional changes. The second, called “public policies”, integrates the effect of all the recently announced measures if they materialize (notably the water plan announced in 2023 after the historic drought of 2022). The third, called “disruptive”, is characterized by a restrained use of water in all areas, with in particular a reduction in meat consumption by 50% for the benefit of fruit and vegetable crops, with a sharp increase in agroecological practices that help keep moisture in the soil. This would be accompanied by a reduction in the consumption of energy, material goods and a significant reuse of wastewater from individuals at the building level.
Agriculture, the most greedy sector
For each scenario, the authors studied the evolution of water withdrawals from rivers and aquifers, which they also call “demand”, in seven areas: irrigation, livestock, energy, industry, tertiary, residential and navigation channels. This analysis details the effects in the metropolis's forty watersheds, and for each month of the year, an unprecedented level of detail.
Ultimately, in all scenarios, agriculture will become the sector with the greatest demand for water (30% of the total), ahead of the energy sector. This is due to increased irrigation, especially in summer, as the increased heat will make crops thirsty. In this season, demand will skyrocket even more in the least restrained scenarios, while the rest of the year it may be much lower than today. Generally speaking, “water demand will be more concentrated during the hottest months of the year, when water resources are at their lowest in aquatic environments”warns France Stratégie. This therefore risks putting biodiversity under severe strain. And the agricultural ponds, which the government wishes to multiply in the territory, will not make a big difference: “The role of substitution deductions in reducing withdrawals between the months of May and September appears moderate”, because peak irrigation demand would only be reduced by 6%, continue the authors of the study.
-In the end, if we add up the changes in all areas and over the whole year, “in the most unfavorable climatic configuration studied, annual demand stagnates in the trend scenario (+ 1%) and decreases in the public policy (- 24%) and rupture (- 47%) scenarios”, calculates the institution.
Up in all scenarios
But the note doesn't stop there. It is also interested in future water consumption in France, that is to say the part of the withdrawals which is not directly returned to nature (because, for example, nuclear power plants pump water to cool down, but they return it to the river, unlike water used to irrigate a field). This consumption is increasing in all scenarios for 2050. In the worst case, that is to say the trend scenario, consumption could be multiplied by two in France with particularly marked warming. The strong need for irrigation could even locally triple consumption in summer in the agricultural watersheds of the Escaut (in the very north of France) and the Adour (in the southwest). “Only the rupture scenario makes it possible to contain water consumption in the case of a dry spring-summer”specifies France Stratégie. Even if it is the most restrained, it nevertheless results in an increase of 10% over the year.
Now that we know what the needs will be, greater or lesser depending on the direction taken, it remains to be determined whether there will be enough water available. Because climate change is disrupting the water cycle and accentuating water extremes. “Water resources have fallen by 14% over the last fifteen years and in the future this trend is expected to increase, particularly in the south of France,” recalled during a press briefing on Monday Hélène Arambourou, deputy director of the sustainable and digital development department of France Stratégie, citing the Explore 2 study on the future of water in France. To continue the foresight, “a work of comparing the demand with the potentially available resource” will therefore be published “by the end of the semester”specifies the institution. A crucial step to make the right political choices and avoid future conflicts.
