More and more scientists call to approach the two questions together, warming aggravating the destruction of ecosystems – and vice versa.
by Audrey Garric and Perrine Mouterde
“This battle against climate change is inseparably a battle for biodiversity, and these two fights are twin.” During the COP27 for the climate in Egypt in early November, a few weeks before the COP15 for biodiversity that opened on December 7 in Canada, President Emmanuel Macron recalled the importance of simultaneously approaching two of the main crises faced by humanity.
For decades, these two fights were waged in a disjoint manner: everyone has their United Nations Convention, their community of researchers, their scientific organization – the Intergovernmental Experts Group on Climate Evolution (IPCC) for One, the scientific and political intergovernmental platform on biodiversity and ecosystem services (IPBES) for the other.
Today, more and more votes are calling to create bridges between these crises, to act on the two fronts and to prevent solutions to one of the problems aggravating the other.
Climatic disruption indeed weighs an increasing threat to biodiversity, and to preserve and protect healthy ecosystems is essential to hope to maintain warming at 1.5 ° C, as provided for in the Paris Agreement.
Same causes, same effects
The two ailments have the same roots. In its August 2021 report, the IPCC showed that global warming is entirely due to human activities. The combustion of fossil fuels (coal, oil and gas) for transport, electricity production, agriculture or industry, as well as deforestation, emit greenhouse gases that are constantly increasing year after year. The concentration in the atmosphere of carbon dioxide (co 2 ), the main one, has reached an unequaled level for at least two million years.
The loss of biodiversity is also caused by anthropogenic activities. The IPBES has prioritized, in its 2019 evaluation report, the five main pressure factors: changes in soil use and the fragmentation of habitats (linked in particular to agriculture and artificialization), overexploitation Species (overfishing, poaching, etc.), pollution, climate change and invasive species.
Combined, these threats have led to an extinction rate of unprecedented species – the vertebrate populations collapsed by 69 % in less than fifty years, one million plant and animal species are threatened with extinction in The next decades – and an alteration of the majority of land and sea ecosystems.
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