At present, of the species of flora and fauna that have been evaluated, 40,000 are threatened with extinction; some groups are profoundly vulnerable, such as the cycads (unique surviving plants from remote times that shared with dinosaurs and are considered living fossils) and amphibians, said Julia Carabias Lillo, from the Faculty of Sciences (FC) of the UNAM.
The rate of extinction has accelerated since the last century, as has the decline of groups of species: it is expected that by the end of the century, one million could expire or be at high risk of eradication, added the expert.
The populations of wild vertebrates have decreased by 68 percent in the last 50 years, and the abundance of wild insects by half, warned the member of the National College, winner of the Belisario Domínguez Medal (2017) and honorary doctorate from UNAM (2019).
Humanity has impacted three-quarters of the earth's surface and two-thirds of the oceans. However, today we are 7.8 billion people and population growth will not stop until it stabilizes between nine billion and 12 billion; that is, between two and four billion more people will still come.
The loss of biodiversity can be stopped, "and that is what we must do at all costs; the situation is hard, complex, but we have to stop it because we can, and there is no human justification that forces us to resign ourselves, in any way".
This problem is due to indirect factors: how many humans we are and how we distribute ourselves in the territory; the production and consumption caused by activities in the agricultural, forestry, hunting, mining, infrastructure, etc. sectors, elements that cause the change of soil use, deforestation, overexploitation, the introduction of invasive species, climate change, contamination, and fires.
In the future, the geographic distribution range of species is expected to decrease, depending on global warming. If we have a temperature increase of 1.5 degrees, between 4 and 8 percent of the species of insects, birds, mammals, and plants would reduce their range; but if the increase is 4.5 degrees, the percentage of species affected would rise between 44 and 67 percent, and their distribution would be more reduced, he said.
The reefs, for example, will decrease by between 10 and 30 percent of the surface area they occupy but could be reduced to one percent of their current coverage if the temperature reaches two degrees Celsius, warned the prominent scientist.
If no action is taken, "we are heading towards collapse, towards extinction"; in contrast, conservation measures can stabilize the species and improve them a little, but this requires integrated actions.
The most successful measure as an instrument of public policy in several countries is that of natural protected areas. They provide benefits such as water and air purification, storing carbon, and mitigating global warming. One-third of the largest cities depend on the vital liquid from these areas, which also improves food security. People who live in or near them live in better conditions.
Before 1995, the Cabo Pulmo area was completely depleted of corals and fish populations; in that year the National Park was decreed and the biomass was enriched by 450 percent, the ecosystem recovered and the economy was activated, because in addition to traditional activities, ecotourism grew.
For Julia Carabias, one of the problems in biodiversity conservation is the lack of harmony in the planning of public policies, that scientific knowledge is translated into them and that the issue of biodiversity is addressed in the context of environmental education. "Despite the importance of protected areas, there is no social commitment. If someone tried to dismantle the pyramids of Teotihuacan, people would rise in their defense, but the same does not happen with natural heritage."