The weak link in the agri-food chain, which is only a food chain organized by mankind, remains that of crop production. Unlike the animal kingdom, plant species depend on the weather conditions imposed by the place where they settle. Unable to escape these conditions, they must survive aberrant manifestations of climate, which will affect most of the vital functions of the plant. This is at least the conclusion to which common sense leads when wondering about the impact on various species, of meteorological anomalies whose frequency increases from year to year. This is actually the reflection I had before I wrote this article. To make it more simple, I have decided to ignore the huge impact of climate change on both diseases and pests that further aggravate the health of plant species. Weakened by this phenomenon, they faced a unprecedented proliferation of enemies – indigenous or introduced through trade – which are favored by climate change.

Both fragile and superficial, herbaceous species – representing a wide majority of crops – are especially sensitive to climate change. We know that storms or hailstorms cause irreversible mechanical damage to these crops. Beyond the droughts that cause water stress and push for fires, heat strokes such as those we have experienced twice this summer, literally sterilize many plants that do not survive these lethal burns more than bursting of cells caused by extreme freezing. The advent of torrential rain would be fatal, I suppose, to the root system and the associated life which would dy from asphyxiation. The repetition of such floodings would also threaten cultivation of rooty vegetables. Apart from these extraordinary situations, most open field crops or veggies are particularly sensitive to certain ordinary weather events when occuring at certain critical stages of their development. This is the case of frost or heavy rain after sowing, when the plant is not yet rooted and its tissues are still fragile. At flowering stage, the same frost or temperatures above 35 ° C prevent production of fruit or seeds, which gives an advantage to perennial crops. When grain ears swell, a drought leads to scalding, resulting in grains that are empty.

If they are particularly vulnerable to previous manifestations of climate change, we can think that herbaceous plants nevertheless have the advantage over woody species, of greater mobility. The shortness of their cycle, as well as an accelerated growth rate, gives them a better chance to escaping the vagaries of weather and moreover, allows them to migrate more quickly to other horizons. This is particularly true for annuals who have the advantage over biennials, to complete their reproductive cycle in one year. This stealth is also true for short-cycle species or C4 plants such as corn or sorghum, whose photosynthetic yield is higher than that of most plants. These more agile species are likely to have a less uncertain future than the others.

Powerless to avoid the living conditions imposed by the location where they settle, the woody species will suffer from the climate deregulation. Scientists from Clermont Ferrand have discovered, during recent heat waves, that trees are traumatized by a demand for water from the canopy such that it induces a rupture of the sap column, due to the impossibility for roots and conductive vessels to answer it. The repetition of such emboli would weaken the woody species to the point of threatening their existence. Added to the damage caused by droughts, strong gusts or overload due to increasingly early snowfall, such a threat will undoubtedly make orchards, vineyards and forests the first victims of climate deregulation. Close to my place, many of these populations have been partially destroyed in recent years, by extreme heats and snowy episodes in fall, with damages when leaves are still in place. The reasoning let us think it is the biggest species of vegetable kingdom – those which seem to us the most robust – who will pay the heaviest price in the climate deregulation. Also I can notice it is the same as for animals : the decline of the animal kingdom whose man is working to eradicate the megafauna, from the extinction of the great sloths, cave bears or other mammoths during prehistoric times, until the current situation where wildlife – endangered for many species – represents only 1% of the mass of animals. Previously, it was the dinosaurs that experienced mass extinction. Exposed to the weather, it is the canopy of botanical species placed at the top of the plant chain which is paying the price for the deregulation, but one might think that it is their underground ecosystem of which we are just beginning to discover the extent and complexity, which is endangered. If the canopy is the visible part to the human eye of the life of trees, it is indeed underground that most of their existence takes place. Just notice that it goes from the ground like the seabed: because they are inaccessible to mankind who lives in a tiny stratum of the atmosphere, people keep on ignoring those parts of the biosphere which probably represent its most important part. Peter Wohlleben’s work on the secret life of trees, reveals us with an anthropomorphism capable of invoking empathy, this hidden face of the life of woody species to which some now lend the supreme virtues – communication, mobility, solidarity, even conscience – which man supposed to be exclusive to his own species. In the long term, this ecosystem will logically suffer from the repeated assaults of the climate deregulation on the canopy which constitutes its Achilles heel. One might think that the hypogeum forest ecosystem is all the less resilient as it is complex and slow to set up. In this respect, cultivated forests and perennial crops are likely to pay the highest price for deregulation as their underground ecosystem will have run out of time to settle. Especially since their accelerated growth goes hand in hand with less dense and therefore more fragile tissues. I borrow a saying from the forest Indians of Asia that « as long as there are trees, there will be men ».

Whether it is extreme weather or ordinary events that occur in an odd order, previous manifestations of climate change undermine the foundations of life. Before joining an engineering school in agronomy, I learned from a university course in biology, that the miracle of this life is a precarious balance. The stability of the environment being posed as a first condition for the preservation of this balance, I do not see how the living could adapt to climate change. This bronze law applies to each species and even more to ecosystems, whether natural or human-induced. In other words, I am far too aware of the dependence of our natural landscapes – to start with the forest – and of agriculture on climate stability to believe that they will resist climate change. Not only would this undermine the integrity of our environment, but it would make it impossible to preserve this balance which defines organic farming and which exempts the farmer from intervening by intensive use of mechanical work and chemistry.

However, a large part of mankind keep on thinking it has solved forever the issue of food production by current farming practice. For my part, I think that the era of abundance which she enjoys at the end of the Thirty Glorious Years will have been only an ephemeral golden age on the scale of its history. This is all the more true since it is only valid for a fraction of the world population established in certain advantageous latitudes. Since the Second World War, Westerners have liked to believe that the production of food raw materials is a perfectly controled process, like industrial activities. We are all the more push to believe in this myth that at a time when the service sector has taken precedence over industry, we live in the illusion of a dematerialized world. Because in just a few decades of rural exodus, most of us have separate ourselves from nature, to turn very recently toward virtual horizons promised by the high tech that invade our daily lives. At the dawn of transhumanism, the « soilless » human race has forgotten it is of flesh and blood and that it lives today on credit. However, the demand in energy of artificial intelligence servers shows the opposite, as does the need for rare earths to manufacture batteries and components necessary for new technologies. Agriculture is no exception to this dependence on natural resources. The announced end of petroleum, essential to modern agriculture for working the soil or providing fertilizers and pesticides, raises the question of an alternative to this mode of production. Perhaps we will soon be unwittingly brought back to the realities of the base of the Maslow pyramid. Climate change would question our primary needs of food, mobility and perhaps even accommodation.