Rising CO2 Levels Threaten Large Bees: New Study Shows Big Pollinators Suffer Most from Carbon Emissions

A new study published in Global Ecology and Biogeography finds that rising carbon dioxide levels are harming the world's largest bees. Researchers examined 25 sites and found that big bee species like Xylocopa and Bombus had smaller populations and less genetic diversity in areas with high CO2. Smaller pollinators appeared to fare better. The study controlled for altitude, temperature, and humidity, isolating CO2 as a key factor. The mechanism likely involves CO2 reducing protein in pollen and altering nectar sugar content. Large bees are critical for pollination because they carry more pollen and fly farther. The authors suggest protecting habitat, planting bee-friendly trees like Eucalyptus and Banksia, and reducing competition from honey bees. The findings add another reason to cut fossil fuel emissions beyond direct climate effects.