Scientists Say “Climate Chaos” is Main Reason for Decline in Bumblebee Population

Bumblebee (Bombus impatiens), the eastern bumblebee, on thistle (a native plant) in Demonstration Garden.

A disturbing study published in Feb. 2019, found that more than 40 percent of the world’s insect species could go extinct over the next several decades due in large part to habitat loss, with chemical pollutants, invasive species and climate change as additional causes.

Now, a new study, published in the Feb. 7, 2020 journal, Science, makes a case for climate change as the principle driver of the potential extinction of bumblebees. Scientists said that observers in North America are nearly 50 percent less likely to see a bumblebee in any given area than prior to 1974.

Using a massive dataset, scientists found that bumblebees are less abundant in areas that have become hotter or have experienced extreme temperature swings in the last generation. The researchers concluded that “climate chaos” is the primary driver in the decline of bumblebees. Species are being pushed beyond temperatures they can tolerate, said the scientists.

According to National Geographic, bumblebees are suited to cooler weather, with fuzzy bodies and the ability to generate heat while flying. The last five years were the hottest ever recorded in the 139 years that the U.S. National Oceanic and Atmospheric Administration has tracked global heat.

Honeybees are critical to the propagation of nuts, fruits and vegetables and account for more than $15 billion in the U.S. economy.