Climate change is causing a dramatic decline in bumblebees across continents in numbers that are consistent with a mass extinction, scientists have warned.
A new study by researchers at the University of Ottawa and University College London found that the likelihood of a bee being at any given place in Europe or North America has declined by a third since the 1970s.
Using data on 66 different bumble bee species across North America and Europe that have been collected over a 115-year period (1900-2015), the researchers were able to see how populations have changed by comparing where bees are now to where they used to be historically.
It is the first time that scientists have been able to link local extinctions and colonisations of bumble bees to climate change.
“We’ve known for a while that climate change is related to the growing extinction risk that animals are facing around the world,” first author Peter Soroye said. “In this paper, we offer an answer to the critical questions of how and why that is. We find that species extinctions across two continents are caused by hotter and more frequent extremes in temperatures.”
The study found that bee populations were disappearing in areas where the temperatures had gotten hotter due to climate change. The researchers were able to predict declines in bumble bees against the measurement of climate change and believe they may eventually be able to apply it to other animal species.
Bumblebees are the most effective pollinators for crops like tomato, squash, and berries. Mr Soroye said that a decline in the species would not just have a detrimental effect on ecosystems, but on food supplies and quality too.
The researchers discovered that bumblebees are disappearing at rates "consistent with a mass extinction".
“We have now entered the world’s sixth mass extinction event, the biggest and most rapid global biodiversity crisis since a meteor ended the age of the dinosaurs,” Mr Soroye warned.
“If declines continue at this pace, many of these species could vanish forever within a few decades.”
However, the researchers said there was still time to act. To allow bees to flourish again, there must be enough environments available that offer them shelter from the heat, like spaces among trees, shrubs and slopes. These environments must be preserved or build up.
“Ultimately, we must address climate change itself and every action we take to reduce emissions will help. The sooner the better. It is in all our interests to do so, as well as in the interests of the species with whom we share the world,” Jeremy Kerr, professor at the University of Ottawa and study author said.
Meanwhile, a climate assembly met for the second time in the British city of Birmingham on Friday.
110 citizens, which have been selected to represent the British public, will learn about energy supplies and how the country uses energy. They will also divide into groups to subjects including “how we travel”, “in the home”, “what we buy”, and ‘food, farming, and land use’.
Each group will hear evidence about what Britain could do to reach its target of net zero emissions by 2050.
The assembly is set to continue until Sunday. The discussions will continue into a third weekend, from February 28 to March 1.
