Benthic marine invertibrates, including sea cucumbers, were among the species assessed.Credit: joebelanger
Global warming will expose thousands of species to dangerous temperatures in the coming decades, doubling the number of those at risk of extinction, according to new research published in Nature Ecology and Evolution.
Human activity is believed to have increased the average global temperature by approximately 1ºC since pre-industrial times, and this anthropogenic climate change poses a major threat to the planet's biodiversity.
The new research suggests that this will worsen throughout the 21st century, during which the average global temperature is projected to rise a further 2.5ºC, and highlights the urgent need to reduce global carbon emissions and mitigate its impact on the environment.
Alex Pigot of University College London, and colleagues, used global climate models to predict how the geographical ranges of animal species will be exposed to dangerously high temperatures up to the year 2100. Geographical data on almost 36,000 species from land and sea environments, including amphibians, birds, cephalopods, corals, mammals, reef fish, seagrasses and zooplankton, was incorporated to model their exposure to dangerously high temperatures.
Data analysis show that the areas at risk of thermal exposure will expand abruptly, with more than half of the projected exposure occurring within a single decade. This will occur for all of the species studied, regardless of how widespread or rare they may be, or whether their geographical range is entirely or only partially exposed to dangerously high temperatures.
The number of species at risk of exposure to dangerously high temperatures will double, from less than 15% to more than 30%, such that the disruption or damage to key elements of the planet's ecosystem may pass a tipping point.
The authors note that the abrupt and pervasive expansion of thermal exposure they have projected may be partly explained by the fact that their climate and geographical data consisted of relatively coarse 'grain size' of 100km-sized grids. Their projections do not take ecological interactions or evolutionary processes into account, which may either delay or amplify the risk of abrupt ecosystem collapse.
Climate change currently affects almost 11,000 species on the Red List of Threatened Species, increasing the likelihood of their extinction.
