Climate change to push species over abrupt tipping points

BUFFALO, N.Y. – A new study led by a team of researchers, including UB’s Adam Wilson, found that climate change will expose species to temperatures above those they have experienced over the past 150 years and may drastically reduce their available habitat.

Even a small environmental variation can lead to a large and abrupt change in the area that a species can persist. For example, if the temperature of a species' habitat rises too high, the species may only survive by moving to a new location, which can be impossible.

The study, published May 18 in Nature Ecology & Evolution, predicts when and where climate change is likely to expose species across the globe to potentially dangerous temperatures.

The authors – Wilson, Alex L. Pigot, University College London (UCL), Cory Merow, University of Connecticut, and Christopher H. Trisos, University of Cape Town –analysed data from over 35,000 species of animals (including mammals, amphibians, reptiles, birds, corals, fish, whales and plankton) and seagrasses from every continent and ocean basin, alongside climate projections running up to 2100.

They investigated when areas within each species’ geographical range will cross a threshold of thermal exposure, defined as the first five consecutive years where temperatures consistently exceed the most extreme monthly temperature experienced by a species across its geographic range over recent history (1850-2014).

Once the thermal exposure threshold is crossed, the animal is not necessarily going to die out, but there is also no evidence that it can survive the higher temperatures due to climate change.

“The loss of biodiversity is concerning because it threatens the stability of ecosystems, disrupts essential ecological processes, and undermines the well-being of both human societies and the planet as a whole,” said Wilson, PhD, an associate professor of geography in the UB College of Arts and Sciences.

The researchers found a consistent trend that for many animals, the thermal exposure threshold will be crossed for much of their geographic range within the same decade.

Pigot (UCL Centre for Biodiversity & Environment Research, UCL Biosciences) is the lead author and said: “Our findings suggest that once we start to notice that a species is suffering under unfamiliar conditions, there may be very little time before most of its range becomes inhospitable, so it’s important that we identify in advance which species may be at risk in coming decades.”

While some animals may be able to survive these higher temperatures, many other animals will need to move to cooler regions or evolve to adapt, which they likely cannot do in such short timeframes.

“To minimize biodiversity loss due to climate change, it is crucial to implement effective conservation strategies, promote sustainable land and resource management practices, and reduce greenhouse gas emissions to mitigate the impacts of climate change on ecosystems,” said Wilson, who also holds an appointment in the UB Department of Environment and Sustainability.

The researchers found that the extent of global warming makes a big difference: If the planet warms by 1.5°C, 15% of species they studied will be at risk of experiencing unfamiliarly hot temperatures across at least 30% of their existing geographic range in a single decade, but this doubles to 30% of species at 2.5°C of warming.

“Our study is yet another example of why we need to urgently reduce carbon emissions to mitigate the harmful effects climate change is having on animals and plants, and avoid a massive extinction crisis,” Pigot said.

The researchers hope their study could help target conservation efforts, as their data provides an early warning system showing when and where particular animals are likely to be at risk.

The study was supported by the Royal Society, the Natural Environment Research Council, the National Science Foundation, the African Academy of Sciences and NASA.