Climate Change Impacts On Bees and Food Production
Impact of climate change on bees and food production
Bees provide the majority of biotic pollination and are at risk from a multitude of factors – changes in
land use, intensive agricultural practices, mono-cropping (growing a single crop year after year on the
same land), and the use of pesticides have all contributed to large-scale losses, fragmentation and
degradation of bee habitats. Pests and diseases are also a threat to bee colonies, some of which have
occurred as a result of transporting bees long distances.
A new set of threats to bees are emerging as a result of climate change. These threats can result in food
insecurity and as three out of four crops across the globe, which produce fruits or seeds for human
consumption, depend on pollinators.
Both bees and plants hone in on specific weather cues, like snow melt or air temperature, to let them know
when spring has sprung. If weather patterns and temperatures shift beyond the norm, plants and bees may
become out of sync, resulting in bees emerging long after the plants are ready to be pollinated.
But here’s the rub: many organismsdepend on relationships with other species — and not all species use the
same cues. One may use mean daily temperature as its phenological cue while another uses day length. If
two species that depend on their interaction with one another use different cues in a changing environment,
or respond differently to similar cues, they may end up missing each other entirely.
For example, a study of bumblebees and the plants they visit in the Rocky Mountains has found that the
timing of both has shifted earlier, but not by the same amount. The shift in flowering has been greater than
the shift in bumblebee timing, resulting in decreased synchrony—and both plants and pollinators may suffer
as a result.
Bees are extremely susceptible to certain mites and gut parasites, and these parasites have been steadily
increasing due to warming weather conditions. Higher temperatures and more frequent heat waves as a
result of climate change are likely to exacerbate these problems in the future, which could cause Colony
Collapse and wipe out entire hives.
As global temperatures rise, North American and European honeybee ranges are getting smaller. In their
most southern habitats, bees are dying from high heat and in their most northern habitats, they are
remaining mostly static, so their range is shrinking.
By some estimates, 35% of all crop species worldwide depend on or benefit from pollination by animals
including bees and other insects). Some 16% of all vertebrate pollinator species (such as hummingbirds and
bats) are threatened with extinction, while at least 9% of all insect pollinators are threatened as well.
Pollinators are essential partners with farmers who grow fruit, vegetables and nuts; without them, our own
species faces loss of an important component of its food source. Similar mismatches may also change and
disrupt relationships between crop plants and pest species, creating new challenges to agriculture or
enhancing existing threats.
Farmers see the changes in phenology in their own fields, and they are already concerned about the future
of agriculture in a changing climate. But we all need to be aware of the impact of climate change on the web
of interactions that make up the world around us, so that we can support lawmakers and others who are
ready to stop the human activities impacting our planet’s climate. Many biologists are out there watching,
accumulating evidence with the systematic eye of science. We must support their efforts—and listen to their
messages about our impacts on the planet and our future.
Thankfully, there are measures that can be taken to reverse the decline of bees and other pollinators.
Whether you are a land manager, a gardener, window-box owner or business, some simple actions include:
Growing more flowers, shrubs and trees that provide nectar and pollen as food for bees and other
pollinators throughout the year.
Planting herbs and vegetables – lavender, basil, mint and tomatoes provide food for bees as well as for
Providing water for bees to take back to the hive.
Avoiding disturbing or destroying nesting or hibernating insects, in places like grass margins, bare soil,
hedgerows, trees, dead wood or walls.
Thinking carefully about the use of pesticides, especially where pollinators are active or nesting or where
plants are in flower. Many people choose to avoid chemicals and adopt methods like physically removing
pests or using barriers to deter them.
Buying locally grown, organic fruits and vegetables to support beekeepers in your area.
As the planet warms, plants and pollinators alike may adjust to the changes in different ways, leading to
mismatches between these symbiotic partners. This impact of climate change on phenology compounds all
the other challenges facing pollinators today, like the loss and fragmentation of habitat, disease, pesticide
use, and the spread of invasive species.