16 August 2021
Disappearing habitats and use of pesticides are driving the loss of pollinator species around the world, posing a threat to 鈥渆cosystem services鈥� that provide food and wellbeing to many millions 鈥� particularly in the Global South 鈥� as well as billions of dollars in crop productivity.
This is according to an international panel of experts, led by the University of Cambridge, who used available evidence to create the first planetary risk index of the causes and effects of dramatic pollinator declines in six global regions.
The bees, butterflies, wasps, beetles, bats, flies and hummingbirds that distribute pollen, vital for the reproduction of over 75% of food crops and flowering plants 鈥� including coffee, rapeseed and most fruits 鈥� are visibly diminishing the world over, yet little is known of the consequences for human populations.
鈥淲hat happens to pollinators could have huge knock-on effects for humanity,鈥� said Dr Lynn Dicks from Cambridge鈥檚 Department of Zoology. 鈥淭hese small creatures play central roles in the world鈥檚 ecosystems, including many that humans and other animals rely on for nutrition. If they go, we may be in serious trouble.鈥�
Dicks assembled a 20-strong team of scientists and indigenous representatives to attempt an initial evaluation of the drivers and risks for pollinator declines worldwide. The research is published today in .
Dr Tom Breeze, co-author of the study and Ecological Economics Research Fellow at the 桃色视频, said:
"This study highlights just how much we still don鈥檛 know about pollinator decline and the impacts this has on human societies, particularly in parts of the developing world.
鈥淲hile we have data on how pollinators are doing in regions like Europe, there are significant knowledge gaps in many others. More research is needed on a global level so we can really understand the problems we face, and how we might address them."
The top three global causes of pollinator loss are habitat destruction, followed by land management 鈥� primarily the grazing, fertilizers and crop monoculture of farming 鈥� and then widespread pesticide use, according to the study. The effect of climate change comes in at number four, although data are limited.
Perhaps the biggest direct risk to humans across all regions is 鈥渃rop pollination deficit鈥�: falls in quantity and quality of food and biofuel crops. Experts ranked the risk of crop yield 鈥渋nstability鈥� as serious or high across two-thirds of the planet 鈥� from Africa to Latin America 鈥� where many rely directly on pollinated crops through small-holder farming.
鈥淐rops dependent on pollinators fluctuate more in yield than, for example, cereals,鈥� said Dicks. 鈥淚ncreasingly unusual climatic phenomena, such as extreme rainfall and temperature, are already affecting crops. Pollinator loss adds further instability 鈥� it鈥檚 the last thing people need.鈥�
A major 2016 report to which Lynn Dicks contributed suggested there has been up to a 300% increase in pollinator-dependent food production over the past half century, with an annual market value that may be as much as US$577 billion.
Reduced species diversity was seen as a high-ranking global risk to humans, which not only risks food security but a loss of 鈥渁esthetic and cultural value鈥�. These species have been emblems of nature for millennia, argue the experts, and too little consideration is given to how their declines affect human wellbeing.
鈥淧ollinators have been sources of inspiration for art, music, literature and technology since the dawn of human history,鈥� said Dicks. 鈥淎ll the major world religions have sacred passages about bees. When tragedy struck Manchester in 2017, people reached for bees as a symbol of community strength.鈥�
鈥淧ollinators are often the most immediate representatives of the natural world in our daily lives. These are the creatures that captivate us early in life. We notice and feel their loss. Where are the clouds of butterflies in the late summer garden, or the myriad moths fluttering in through open windows at night?鈥�
鈥淲e are in the midst of a species extinction crisis, but for many people that is intangible. Perhaps pollinators are the bellwether of mass extinction,鈥� said Dicks.
Loss of access to 鈥渕anaged pollinators鈥� such as industrial beehives was ranked as a high risk to North American society, where they boost crops including apples and almonds, and have suffered serious declines from disease and 鈥榗olony collapse disorder鈥�.
The impact of pollinator decline on wild plants and fruits was viewed a serious risk in Africa, Asia-Pacific and Latin America 鈥� regions with many low-income countries where rural populations rely on wild-growing foods.
In fact, Latin America was viewed as the region with most to lose. Insect-pollinated crops such as cashew, soybean, coffee and cocoa are essential to regional food supply and international trade right across the continent. It is also home to large indigenous populations reliant on pollinated plants, with pollinator species such as hummingbirds embedded in local oral culture and history.
Asia Pacific was another global region where pollinator decline was perceived to pose serious risks to human well-being. China and India are increasingly reliant on fruit and vegetable crops that need pollinators, some of which now require people to pollinate by hand.
The researchers caution that not enough is known about the state of pollinator populations in the Global South, as evidence of decline is still primarily from wealthy regions such as Europe (where at least 37% of bee and 31% of butterfly species are in decline). A deficit of crop pollination and loss of species diversity were seen as the biggest risks to Europeans, where losses could affect crops ranging from strawberries to oilseed rape.
Full Citation:
Dicks, L.V., Breeze, T.D., Ngo, H.T. et al. A global-scale expert assessment of drivers and risks associated with pollinator decline. Nat Ecol Evol (2021).
We are in the process of finalising our postgraduate taught courses for 2027/28 entry. In the meantime, you can view our 2026/27 courses.
