Some species are pre-adapted to tolerate climate change

In a recent study, researchers at the French Institute for Oceanic Science (Ifremer) and Lausanne University reassessed the impact of changing environmental conditions on species extinctions. The experts developed a new model to estimate the number of terrestrial and marine species that are threatened with extinction as a result of climate change.

While traditional models predicted a 54% decline in tropical terrestrial species by 2041-2060, the new model forecasts a more moderate 39% decline. Despite this lower estimate, the results remain concerning, emphasizing the urgent need for climate action to protect biodiversity.

Species pre-adapted to past warmer climates

Temperature variations on Earth range from -70°C in Antarctica to +48°C at the equator. Historically, climatic conditions have shifted, and species may have pre-adapted to past warmer climates similar to those expected by the end of the century.

Previous models did not account for this potential pre-adaptation, leading to possibly inaccurate predictions.

“Take the example of a tropical marine or terrestrial species: traditional statistical models predict that it will disappear in places where the temperature exceeds the current warm limit of 48°C. But this view could be too restrictive, as our knowledge is limited by the study of current climatic conditions,” said lead author Mathieu Chevalier, a marine ecology researcher at Ifremer.

“When a species is ‘marked’ by climatic conditions, it retains a pre-adaptation to these conditions that can last for thousands or even millions of years,” added senior author Antoine Guisan, a professor of spatial ecology at the University of Lausanne.

“If its habitat evolves towards a climate that the species has already experienced in the past, this pre-adaptation will provide it with a tolerance to these new climatic conditions.”

Species approaching climatic limits

The researchers applied their model to nearly 25,000 terrestrial and marine species worldwide. They discovered that 49% of these species live in climate niches near the current climatic limits, and 86% could potentially extend beyond these limits, with this figure rising to 92% for marine species.

“The most striking result concerns tropical areas, for terrestrial and marine species,” said Chevalier. “It is widely accepted that climate change will lead to a massive loss of biodiversity in these areas, up to 54% of tropical terrestrial species by 2041-2060 according to traditional models. Our model puts this prognosis into perspective and predicts a reduction of ‘only’ 39% in species diversity.”

Factors influencing species extinction risk 

Despite the seemingly less dire prediction, scientists caution that this remains an alarming estimate. They emphasize that climate is not the sole factor influencing species extinction risk. Other anthropogenic pressures, such as habitat loss, pollution, and biological invasions, must also be considered.

“Our study shows that it is important to constantly refine our models, and develop new hypotheses about the possible response of certain species,” said co-author Olivier Broennimann, a researcher in spatial ecology at the University of Lausanne. 

“If it is likely that tropical species could better tolerate climate change than previously thought, the old estimates remain valid for species in cold, alpine, and polar regions, and to a large extent for species in temperate zones, because the climate that currently prevails in these areas will no longer exist by 2041.”

These findings highlight the need for continuous model refinement and the development of new hypotheses to better predict and mitigate the impacts of climate change on biodiversity.

More about species extinction risks

Species extinction risks are shaped by various factors, including habitat destruction, climate change, pollution, invasive species, and overexploitation. 

Habitat destruction 

Habitat destruction, often due to agricultural expansion, urban development, and logging, disrupts ecosystems, making it difficult for many species to survive. 

Climate change and pollution

Climate change further exacerbates these challenges by altering temperature and weather patterns, which can shift habitats and affect species’ survival rates. 

Pollution from chemicals, plastics, and other waste degrades natural environments, harming or killing wildlife that depend on these habitats.

Invasive species and overexploitation 

Invasive species introduced to new environments can outcompete native species for resources, leading to declines in native populations. 

Overexploitation through hunting, fishing, and trading also poses a significant threat to species, particularly those targeted for their meat, hides, or other products. 

Cumulative impacts

The cumulative impact of these factors has led to a significant rise in the rate of species extinction, posing severe consequences for biodiversity and ecosystem services that support human life. 

Efforts to mitigate these risks include conservation programs, protected areas, sustainable practices, and international treaties aimed at preserving vulnerable species and their habitats.

The study is published in the journal Nature Ecology & Evolution.

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