Climate change and bees
The effect of climate change on beekeeping is currently entirely speculative and likely to occur in ways that are not predictable. An internet search on the topic reveals almost no information of any worth. The topic is wide open for discussion - and, knowing beekeepers, heated debate. However, some ideas may be considered as logical possibilities and may help beekeepers to inform themselves of the problems that may arise for them in coming years.
Potentially, the most significant problem - and one that affects everyone who eats - is disruption of vital plant-pollinator relationships. This is most likely to be characterised by a change of the timing of nectar flows. There are now sufficient independent observations available to confirm that plants are flowering earlier. An example of this is given on the NASA website (Honey Bee Net) where data from Maryland, USA collected using satellite technology indicates peak nectar flows occurring almost a month earlier than in the 1970's. Bees and flowering plants have a long evolutionary relationship, developed over the millennia to be mutually beneficial. The relationship is predicated on maximum colony populations coinciding with peak flowering times so that maximum food is available to meet the bees' nutritional demands. This arrangement also maximises pollination opportunities for the plants. When the timing of this relationship breaks down the bee colony is damaged, maybe to the point where the nectar and pollen resources available are insufficient to support the life of the colony, while the plants suffer from inadequate pollination services. How disruption of these complex relationships will affect both agriculture and whole ecosystems needs detailed research but it may affect both plants and pollinators in ways that may be critical their survival.
Insufficient forage and unpredictable weather conditions at peak population times encourages swarming. This is a consequence of bees not being able to get out to forage which reduces the number of bees in the hive at any given time. Over crowding results in inadequate spreading of queen substance among workers which would normally suppress their swarming instinct. Excessive swarming occurring when there are insufficient flowering plants to meet a new colony's nutritional needs may lead to high numbers of colony deaths or poor productivity that will discourage beekeepers from caring for bees. Particularly in places where varroa makes beekeeper input essential to the bees' survival this could lead to loss of, or dramatic reduction in, entire populations.
At a more local level, bee colonies can be lost to severe weather events characteristic of climate change. Bees and hives can be destroyed by flooding or fire. Intense heating, especially under tropical conditions, can lead to the collapse of the honeycomb especially if water for cooling becomes less easily available. Unseasonal rain or coolness affects the ability of queens to mate successfully ultimately compromising colony survival. Swarming, migrating and absconding, either excessively or at the wrong time of year, is likely to further compromise colony survival. Climate change may also impact on absconding and migration patterns in unpredictable ways. There may not be sufficient time for bees to adapt to meet the challenges of climate change without significant loss of populations and with that the genetic diversity required for continued colony vigour.