Gabriel García Márquez titled one of his columns: “The countryside, that horrible place where raw chickens wander around“. The writer was alluding to the growing distance between the urban (the city) and the rural (the countryside) for European people of the 1980s. They were the first generations of children that didn’t know everything about the nature of chickens, except those that emerge roasted from the oven, and the first generations of chickens unaware of the terror of being chased around by untiring human offspring.
The countryside became a lost world; although the truth is that the planet lives in a spiral of constant change, where the greatest certainty is, in fact, change. In the case of the natural environment, before it had become rural, it had been another lost world with a much more exciting name: the wild. Today some scientists suggest that recovering that lost wild world could help us fight against the most worrisome change of our era—the climatic one.
In the late Pleistocene—about 14,000 years ago— modern humans (Homo sapiens) had already arrived in Europe. At that time —by the end of the last ice age—, lions, reindeer, wild horses and bison roamed Europe and legendary mastodons lumbered across North America. Scientific evidence indicates that the wild world was peering over the precipice, due in part to the intense hunting activity practiced by humans.
After thousands of years of agriculture and raising livestock, and the massive deterioration of ecosystems worldwide, populations of amphibians, fish, reptiles, mammals and birds have decreased globally by almost 60% between 1970 and 2014. This loss not only implies the almost total disappearance of charismatic species such as the white rhinoceros, the panda, the Bengal tiger and the Sumatran elephant, but also of their functions in the ecosystems.
The return of missing animals
To restore these lost worlds, conservation science increasingly relies on what is known as trophic rewilding: the reintroduction of missing animals or those with very small populations, from elephants to giant tortoises, from rhinoceroses to bison, to restore trophic chains—the famous “who eats who” in the wild—and that ecosystems regulate themselves.
The most famous case is the reintroduction of wolves into Yellowstone National Park (USA) in the 1990s, and almost the only one in which there is no doubt that the ecosystem changed: the density of deer decreased and large areas of forest were recovered. Rewilding now refers not so much to a form of conservation of species on the verge of vanishing completely, like the Iberian lynx in Spain, but to rewilding large expanses of territory, particularly with large herbivores.
The most intrepid biologists wonder if rewilding could even affect the climate. In the Arctic, for example, the situation is so extreme that in a few years the ice in summer may only exist as a memory. Thermophilic plants invade the tundra as global temperatures increase, while the ice inexorably melts and decreases the albedo (the solar radiation reflected by the Earth and that is higher in the ice and snow), which in turn increases the warming effect. Some climatologists refer to this as the “Arctic death spiral.”
In this delicate world, the caribou (wild reindeer) and the musk ox are the only great herbivores. The number of caribou, however, has decreased by around 56% in less than 20 years. As they are the only consumers of the excess of plants, a recent study has proposed strengthening their populations to control the vegetation and increase the albedo.
Keep instead recover
The study also suggests reintroducing large herbivores into tropical forests, which are being replaced by palm and soybean fields, arguing that the loss of fauna limits the dispersal of seeds and with it the regenerative capacity of forests that absorb CO2. Finally, the authors propose replacing traditional livestock—cows, goats and sheep—with large non-ruminant herbivores, for example horses, which produce less methane (a greenhouse gas) in their digestive systems.
In spite of how captivating it may be to see bison repopulating the lands of Europe—they already exist on some farms—rewilding is not exempt from criticism. The biologist Miguel Delibes de Castro, former director of the Biological Station of Doñana (Spain) and one of the greatest experts in the conservation of the Iberian lynx, is not convinced by the idea: “The world changes very fast and it is a bit utopian to think that we can rebuild an ecosystem from long ago,” he says. “As an idea, it’s nice, attractive and generates enthusiasm, but it’s doubtful that this is a reasonable way to conserve nature on a global scale, to reverse the trend of destruction.”
According to Delibes de Castro, nature is being lost at a much faster rate than rewilding can hope to counteract, so it would be preferable to devote greater efforts to conserving what is deteriorating now, rather than to recover what has already deteriorated. “Climate change is going very fast,” he warns. “We can’t say: let’s see if in 100 years we are drinking mare’s milk and eating horse meat… It might be, but by then where will the sea level be, the CO2 level…? It’s more urgent to try to stop CO2 emissions.”