11 August 2023

Climate change anticipates bee awakening putting crops at risk


British study: rising spring temperatures make bees wake up too early. Synchronization between insects and plants is lost and crops are affected. 1°C warming corresponds to an average anticipation of 6.5 days

by Matteo Cavallito


Climate change is affecting the life rhythms of bees with negative consequences for crops that rely on their pollination services. This is supported by a study from the University of Reading in the United Kingdom. Warmer springs, in particular, would be causing British bees to wake up earlier with the result that they lose synchronization with plants.

By leaving the nest earlier, in other words, the insects may lack the energy needed to pollinate crops effectively or may miss flowering altogether. This problem would spill over into the plant life cycle ultimately leading to a reduction in available food.

Pollination services at risk

“Matching wake-up dates with plant flowering is vital for newly emerged bees because they need to find pollen and nectar to increase their chances of survival and produce offspring,” explained Chris Wyver, a researcher at the School of Agriculture, Policy and Development at the University of Reading in a statement released by the same British university. In the event of an early exit from lethargy, in fact, insects would face food shortages.

In this context, overall pollination is reduced, generating an environmental imbalance and a problem for producers. With inevitable consequences, including economic ones, for everyone.

“Less natural pollination could lead to farmers needing to use managed honeybees, meaning greater costs, which may be passed on to consumers,” Wyver adds. “We could see even more expensive apples, pears and vegetables in supermarkets as a result.”

Just 1°C more is enough to wake up a week earlier

The study examined 88 different species of wild bees over a 40-year period, using more than 350,000 individual records that showed changes in emergence dates, both over time and in relation to temperature. “The analyses reveal widespread advances in emergence dates of British wild bees, at an average rate of 0.40 days per year since 1980 across all species in the study data set,” the study explains.

Moreover, “Temperature is a key driver of this shift, with an average advance of 6.5 days per 1°C warming.”

Some bees, the researchers explain, would emerge earlier than others because different species respond differently to temperature change. According to projections by the Met Office, the U.K.’s national weather service, winters between now and 2070 will experience a temperature increase of between 1 and 4.5°C with a maximum increase of 30 percent in humidity. From these conditions, it is likely that the trend of early awakening by bees will find confirmation.

api insetti impollinatori servizi ecosistemici vantaggi agricoltura

Bees and pollinating insects in general play a crucial role in our food security and ecosystems. Here are five of the “services” provided by them. Source: FAO Archives.

Most of the world’s food depends on bees

The early exit of bees is bound to impact especially some plants such as apple trees, for example, which may not be ready to flower so soon. What is certain is that the consequences of climate change on bees and their behaviors is an issue of enormous importance in the face of its potential implications.

Three out of every four food crops in the world depend to some extent on bees and other pollinators. However, the decline of these insects is increasing. Yet the global food economy is showing a significant increase in demand for pollination services, especially in developing countries,FAO recalled on World Bee Day in May last year.Without these insects, the U.N. organization further highlighted, a large number of wild and cultivated plant species would no longer exist. Indeed, as many as 71 of the 100 or so crop species that provide 90 percent of the Planet’s food are pollinated by bees.