This post was updated on August 22, 2022.
Did you drink coffee or eat an apple today? Thank a bee.
About one out of every three bites of food is made possible by honeybees and other pollinators. Worldwide, they help produce US$ 170 billion in crops per year. But the world’s honeybees are in steep decline, with populations decreasing by about 45 percent in the United States between 2020 and 2021 alone.
Honeybees are largely a domesticated species carefully managed by beekeepers all over the world. They are just one of a dizzying variety of nearly 20,000 bee species found worldwide. Many native bees — which are critical to healthy ecosystems and biodiversity — are in even greater danger and are rapidly disappearing from the wild at astonishing rates.
While the reasons behind the decline of bees are numerous and varied, it is abundantly clear that each species of special pollinators is highly susceptible to climate change. Here’s how our changing temperatures are making life harder for bees.
1. Habitat loss
Climate change is causing habitat loss as bees fail to migrate to cooler areas and establish new hives. A study on bumblebee migrations found that bee territories have shrunk by nearly 231 km (200 miles) in North America and Europe. In South Africa, Conservation International is advocating for the protection of the Cape Floral Region — an incredible pollinator hotspot with the highest known concentration of plant species in the world.
2. Shifting temperatures
As average monthly temperatures rise, flowers may bloom earlier in the spring, creating a potential mismatch in seasonal timing between when flowers produce pollen and when bees are ready to feed on that pollen. Even a small misalignment of three to six days could negatively affect bees’ health, making them less likely to reproduce and less resistant to predators and parasites.
Additionally, some types of bees such as bumblebees are sensitive to temperature due to their large, hair-covered bodies. A recent study revealed that bumblebee populations have declined by nearly 50 percent in North America and Europe — likely due to a series of extreme heatwaves.
3. Disease
Honeybees are susceptible to parasites such as Varroa mites and the gut parasite Nosema ceranae, and environmental stresses may increase infections. Scientists first discovered the Nosema ceranae in the early 1990s in Asian honeybees. It has since spread to Europe and the U.S., causing shorter lifespans and colony collapse. A recent study found that lower temperatures were associated with lower prevalence of the parasite, indicating that higher temperatures as a result of climate change could result in more bees infected with Nosema ceranae.
How can you help save pollinating professionals? Experts suggest starting with the bees and other insects in your own backyard: Plant a pollinator-friendly garden designed to maximize blooming for most of the year. In urban areas, porch and window planters can provide important food sources for bees.
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Further reading
