What is the connection between the climate and biodiversity?

Biodiversity (all the species that populate our planet: plants, bacteria, animals, etc.) has been through a sharp decline for half a century. The crisis it is undergoing is multifactorial. Those you can see directly are deforestation, chemical pollution and overexploitation of resources. We, therefore, also have to add climate change.

To summarise, we could say that the warmer it gets on Earth, the greater the number of species that suffer increases. Well, all ecosystems are now exposed to global warming and its consequences: wetlands, deserts, mountains, tropical forest, oceans, rivers, etc.

Species are trying to adapt to survive. They are doing so in several ways. They can firstly evolve. It is known as the climate's "evolutionary pressure" on species, which develop new traits to cope with environmental constraints. For example, trees overexposed to the heat start producing smaller leaves. The kidney wood, an Australian shrub, is a case in point that has found this solution to compensate for the rise in local temperatures (+1.5°C between 1950 and 2005). Other examples, in France this time: researchers at the National Museum of Natural History have discovered that birds are born smaller in warm years. In fact, a smaller body means a body that is easier to cool down...

Not all species are equal when it comes to their ability to adapt . There are winner and .... losers.

With the winners often referred to as "generalist" species, with more flexible in their needs.One example is the Asian hornet, which has taken delight in colonising a warming France since 2004; or the Tiger Mosquito, which appeared in the 2000s in the Camargue in France, now present in...60 French departments. Some even announce the imminent arrival of another invasive species in France: the Javan mongoose…

Conversely, the losers are generally " specialised". Overwhelmed by the scale and speed of climate change, they are doomed to decline or even extinction. A typical example: vegetation on mountain summits. These plants already cannot climb any higher to escape the rise in temperatures.If we are incapable of containing global warming, most will disappear. In Europe, it is estimated that a quarter of all flowering plants on the continent are only found high up in the mountains... … Meaning thousands of species are on borrowed time.

In a 2019 report, IPBES estimates that nearly 1 million species are at risk of extinction in the coming decades..

The famous boomerang effectGlobal warming amplifies the collapse of biodiversity… which amplifies global warming.

Biodiversity provides what are known as "environmental services": positive effects that benefit ecosystems, which themselves regulate the Earth's climateWhat do these services fundamental do? Regulating the amount of CO2 in the atmosphere. Biodiversity is not idly compensating for our excesses: land and marine ecosystems absorb almost half of the CO2 emissions generated by humans. In fact, by capturing this greenhouse gas, peatlands, wetlands, soils, forests, and oceans limit global warming. Some species, in particular, are unsuspecting allies, says the WFF… : whales, forest elephants or sea otters.

Another service provided by biodiversity: a natural form of protection against the consequences of climate change. Any examples? Wetlands that regulate and limit flooding; trees that create life-saving microclimates during heat waves; or coral reefs that protect coasts from waves and storms.