Destroyed ecosystems, polluted water, old air, hundreds of thousands of species threatened with extinction … “Much of nature has already been lost and what is left continues to decline”.
This is the alarming finding made by the UN Group of Experts on Biodiversity (IPBES) in Paris this week, according to a 1,800-page draft obtained by AFP.
Nature, source of wealth …
Water, food, energy, textiles, minerals, medicine … Nature provides invaluable services to man.
Agricultural production, which is mainly made possible by soil and pollinating insects, is thus constantly increasing, and fish catches have increased by 50% over the last 50 years.
More than 2 billion people use wood as an energy source. And between 25 and 50% of the drugs come from nature.
Plants and microorganisms also play a crucial role in the filtration of water and air. And plants and gardens absorb more than half of the CO2 emissions responsible for climate change.
… who are exhausted
Men exploit and pollute nature more than ever in history. As a result, “today, 75% of the terrestrial environment, 40% of the marine environment and 50% of waterways show significant signs of deterioration”, according to the draft report.
More than 40% of the land is now agricultural or urban, and only 13% of the seas and 23% of the land are still classified as “wild”, in places that are often very remote or unproductive.
“More than a third of the land and three quarters of water resources are used for agricultural production and livestock,” the text reads. But soil degradation has reduced agricultural productivity by more than 20% of the earth’s surface, affecting more than 3 billion people.
And agriculture continues to expand, especially “at the expense of the rainforest”.
Between 1990 and 2015, global forest cover fell by about 6%, from 4.28 billion hectares to 3.99 billion.
With almost 60% of the world’s population living in cities, urbanized areas have doubled since 1992, mainly taking over savannas and grasslands.
The pollution is harder to assess, but fertilizer consumption has increased.
More than 80% of the planet’s wastewater is discharged into the environment without treatment and at the same time “300 to 400 million tonnes of heavy metals, solvents, toxic sludge and other waste are discharged into the water every year”. Thus, “40% of the world’s population does not have access to clean drinking water”.
The oceans, where millions of tonnes of plastic are dumped every year, are not much better. The 70,000 vessels in the industrial fishing fleet now cover “at least 55%” of the seas. And “almost 75% of the main fish stocks” are now depleted or overexploited.
“Deaths on borrowed time”
Scientists estimate that there are about 8 million animal and plant species on the planet. But only a small proportion of them are evaluated.
Thus, about 25% of the approximately 100,000 species reviewed by the International Union for Conservation of Nature (IUCN) for its famous red list are classified as endangered, and 872 have been extinct for 500 years.
But the text of IPBES is much more dramatic: between 500,000 and one million species are currently at risk.
Extrapolated from assessments of several species, it is “likely that at least one million species of animals and plants (…) today are threatened with extinction”, assesses the draft report. .
Using another method of prediction based on habitat loss, the researchers arrive at a likely “conservative” figure of half a million – including more than 3,000 vertebrates and more than 40,000 plants. These species are “dead on borrowed time” because they are probably already “doomed to extinction” due to the damage already inflicted on their habitats.
The draft report also notes a “widespread decline” in animal populations, both on land and at sea, although studies mainly focus on vertebrates. As well as a decrease in genetic diversity.