Rising CO2 harms large bees

A new peer-reviewed study published in Global Ecology and Biogeography, led by Kit Prendergast of the University of Southern Queensland and Curtin University, examined bee and hoverfly communities across 25 sites in Pakistan with naturally varying CO2 concentrations. The researchers found that higher atmospheric CO2 levels are associated with reduced abundance and genetic diversity of larger-bodied bees, including Bombus asiaticus, Xylocopa pubescens, and genera Xylocopa pubescens, Amegilla, and Bombus asiaticus. In contrast, smaller-bodied genera such as Ceratina and Lasioglossum appeared more resilient or even thrived under higher CO2. The study suggests elevated CO2 reduces pollen protein content and alters nectar chemistry, making it harder for large bees to meet their energy demands. Because large bees are among the most effective pollinators, their decline raises concerns for global food security and biodiversity. The findings highlight CO2 as an underappreciated factor in pollinator decline, alongside habitat loss and pesticide use.