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Temperature Extremes and ‘Climate Chaos’ Driving Bumblebees to Extinction

In the midst of devastating climate change, new evidence shows the bumblebee population has declined drastically throughout North America and Europe – allowing scientists to develop a trailblazing extinction-prediction method.

(CN) – In the midst of devastating climate change, new evidence shows the bumblebee population has declined drastically throughout North America and Europe – allowing scientists to develop a trailblazing extinction-prediction method.

A study conducted by researchers from the University of Ottawa revealed the chilling statistic that over the course of a single human generation, the likelihood of a bumblebee population surviving in any given location has currently declined by an average of over 30%.

Authors Peter Soroye, a doctoral student of biology at the University of Ottawa, Jeremy Kerr, University of Ottawa professor and head of lab group with Soroye, and Tim Newbold, research fellow at University College London, spearheaded the study. Their research has linked the idea of “climate chaos” to different extinctions and found that those extinctions actually began decades ago.

"We've known for a while that climate change is related to the growing extinction risk that animals are facing around the world," Soroye explained. "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."

In their study, published Thursday in the journal Science, they looked specifically at the bumblebee population as an indicator for extinctions as they relate to changes in the global climate.

"Bumblebees are the best pollinators we have in wild landscapes and the most effective pollinators for crops like tomato, squash, and berries," Soroye observed. “Because they are so big, when they land on a flower it creates what is called buzz pollination. When they land, and they move around and buzz, it shakes the whole flower and knocks off pollen in amounts that plants and crops need and that smaller bees can’t produce.”

The researchers discovered that bumblebees are disappearing at rates "consistent with a mass extinction."

"Our results show that we face a future with many less bumblebees and much less diversity, both in the outdoors and on our plates," Soroye warned. "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. If declines continue at this pace, many of these species could vanish forever within a few decades."

The authors note that while it is grave news, with enough research and changes in human habits, it can be helped.

"We know that this crisis is entirely driven by human activities," Soroye said. "So, to stop this, we needed to develop tools that tell us where and why these extinctions will occur."

The team looked at climate change and observed how it increases the frequency of extreme natural events such as heat waves and droughts, creating conditions that inspired the term “climate chaos.” These rapidly changing weather conditions can be extremely dangerous for animals in the affected regions. Keeping in mind that all species have varying tolerances for temperature – the ideal degree of heat for one might be too much for another – the researchers developed a new measurement of temperature itself.

"We have created a new way to predict local extinctions that tells us, for each species individually, whether climate change is creating temperatures that exceed what the bumblebees can handle," Newbold explained.

To test their hypothesis and new technique, they utilized data from 66 different species of bumblebees from across North America and Europe that have been collected over a 115-year period, from 1900 to 2015. The team saw how these bumblebee populations have changed by comparing the location of the bees now to where they used to be in the past.

“We sat down and sketched ideas on a white board not just about bumblebees but more generally about how climate change affects all animals,” Soroye said. “Using a collection of bee sightings, we could test out these ideas and account for changes and data, and we built techniques to see how climate change affects other species and where.

“We were really surprised when the research started to see everything starting to work. When we plotted our first figure and it matched perfectly to our sketches on the white board, we knew that we had struck a gold mine,” Soroye added.

The gold mine was discovering a link between disappearance of the bees and rising temperatures.

"We found that populations were disappearing in areas where the temperatures had gotten hotter," Soroye said. "Using our new measurement of climate change, we were able to predict changes both for individual species and for whole communities of bumble bees with a surprisingly high accuracy."

The authors emphasized their research is just the beginning, and it will open countless doors allowing scientists to track extinction levels for different species including reptiles, birds, and mammals.

"Perhaps the most exciting element is that we developed a method to predict extinction risk that works very well for bumble bees and could in theory be applied universally to other organisms," Soroye said. "With a predictive tool like this, we hope to identify areas where conservation actions would be critical to stopping declines."

Kerr, a co-author, said the findings can also apply to humans.

“What we’re talking about is fundamental to any organism, even humans. Take for example if we took a family from Chicago and moved them to Arizona overnight. It would be 20 degrees Celsius (36 degrees Fahrenheit) warmer and would present very real challenges for those people,” Kerr explained. “This is the same way rapid climate change affects organisms who are stuck in one spot. They are beginning to experience conditions beyond what they can handle.”

He added: "Predicting why bumblebees and other species are going extinct in a time of rapid, human-caused climate change could help us prevent extinction in the 21st century.”

The authors also emphasized that while the state of the bumblebee population looks bleak, there is still time to act.

“Sometimes when you open a doorway, it leads to a broom closet, but sometimes it leads you to a massive vista of potential, and that’s what we’re looking at. Suddenly we find ourselves standing in the frontier,” Kerr said.

Soroye said while bees and wildlife going extinct is a depressing prospect, “we are hopeful about what this means for the future in terms of developing tools and techniques to see where we should step in.”

Kerr agreed.

“There is a lot of hope. When it comes to climate change contributing to extinction, it’s not the fact that it’s happening that we look at, it’s why it’s happening. When we know why, we can then sensibly ask how can we intervene, how can we manage the land for better outcomes,” Kerr said.

Categories / Environment, Science

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