[LUM#2] Homo Mediterraneus condemned to evolution

[LUM Magazine] - Published on April 12, 2016 in Science-Society

And what about humans? What impact will this have on populations, societies, and economies? Focus on a Mediterranean region threatened by turmoil.

Nothing is more difficult than painting an accurate picture of the fate of human societies, explains Eric Servat, director of the Research Environment Research Observatory (OSU OREME). But what can we say with a reasonable degree of certainty? First, the Mediterranean climate will become increasingly unstable. "This virtually closed environment, where average temperatures are expected to rise by 2 to 4 degrees by 2100, behaves like a pressure cooker when heated." The result: severe weather instability is to be expected throughout the region. And severe flooding: this already accounts for a third of natural disasters and more than half of the deaths caused by these disasters.

Water at the center of concerns

Longer dry periods and wetter winters that will not be enough to compensate for them: in total, the annual rainfall deficit in the Mediterranean is predicted to be between 5 and 30%. This is a disaster for many regions on the southern shore and in the Middle East, which are already below the critical threshold of "water stress." The situation is exacerbated by population growth and concentration...

"By the middle of this century, two-thirds of humanity will be living in coastal areas, in the broadest sense of the term. This will lead to increased pressure on local resources and highly concentrated pollution," continues Eric Servat. These populations will need to be fed... Yet today, 70% of the fresh water available on our planet is used for agriculture. "In a changed and degraded context in terms of water resources, these demographic changes mean we have to imagine a form of agriculture that is adapted to the future."

Growing inequalities

With sea levels rising at an accelerating rate, the risk of coastal flooding is increasing along the French coastline—where the sea will rise by 26 to 55 cm by 2100—threatening populations and infrastructure. We can therefore expect to see climate refugees in our part of the world. However, this risk mainly concerns the southern coast. Uneven development leads to uneven vulnerability: not all human societies are equally threatened.

In the north, structures and resources should enable adaptation. Vineyards in difficulty, chestnut groves on the verge of extinction? Scientists believe this is to be expected. But "climate change is also a source of new opportunities, " points out Patrice Garin, a researcher at the "Water Management, Stakeholders and Uses"laboratory: this will be the case in our mid-latitudes, with the possibility of seeing orange and lemon trees flourish." In the south, on the other hand, where severe droughts are already raging, some populations will have to leave lands that can no longer feed them.

Promoting agrodiversity

And when agricultural production is threatened in the Mediterranean, "it is the cradle of agriculture that is affected," says Yildiz Aumeeruddy-Thomas, a researcher at the Center for Functional and Evolutionary Ecology. " The wild ancestors of the cereals and legumes that feed humanity today are here," she explains. This agrodiversity is a major pillar of global food security. "Today's plantations are often monoclonal: a single individual, replicated thousands of times." These are highly specialized varieties, created in laboratories for their productive capacities. But they are also "aberrations in terms of the environment," according to the ethnobiologist...

"By planting monocultures, we lose not only genetic resources, but also valuable know-how. Instead, we should promote older, hardier varieties that are better suited to their environment. And we should encourage biodiversity in agroecosystems to increase their adaptability." Focusing on food security rather than overproduction for export is also a guarantee of food quality that pays off. "Conventional agriculture requires the massive use of chemicals, which have a huge cost in terms of public health, something that must be taken into account in the future when considering new agricultural models."

Cost of inaction

While disruption seems inevitable, its extent will depend on the ability of public policy to manage the crisis. For Patrice Garin, "we need to think about other ways of sharing territory, developing and occupying space, and urbanizing." He advocates a model of society that is "more frugal and more respectful of the environment." He also calls for the participation of civil society, particularly scientists, to support decision-makers in exploring the range of possibilities.

Whatever strategies are pursued, they will come at a cost. But "doing nothing costs even more," points out Sophie Thoyer, professor of agricultural and environmental economics and researcher at the Lameta laboratory, now known as CEEM. "According to some studies, it is estimated that the cost of inaction increases by 40% every 10 years. Not to mention the irreversible, incalculable effects: the disappearance of the ice cap, for example."

This observation comes at a time when political will is lacking. Has Europe grasped the urgency ofthe situation? "The Common Agricultural Policy has recently become greener. But the measures taken are very timid in view of the challenges and will have only a very small impact on the environment." And what about the non-binding agreement signed at the recent COP21? For Sophie Thoyer, "it has incremental value. Its success lies in having achieved a consensus among 195 countries and reignited momentum, with the aim of securing increasingly significant commitments." This gentle approach could bear fruit. But how long will it take?

Keywords: Climate change, Climate, LUM#2, LUM Magazine