China's rapid expansion of solar power has come with an environmental cost: bird diversity has fallen in counties that pushed solar development hardest, according to a study published in the journal Science. Researchers compared solar policies and birdwatching records across 2,344 Chinese counties from 2014 to 2023 and found a steady link between stronger pro-solar rules and fewer bird species.
A green dilemma
The authors describe the result as a "green dilemma" that pits carbon reduction against wildlife conservation. Building solar farms cleared cropland and grassland that birds use for food, shelter and nesting, and the habitat that remained became more fragmented. The team found that a one-standard-deviation increase in the intensity of solar policy was tied to a 2.1 percent drop in a bird diversity index, a moderate but consistent effect across the country.
Where the losses were worst
The decline was sharper in wealthier regions and in non-desert areas, where solar farms tended to replace productive farmland and natural grassland. Both resident and migratory birds lost ground. Species native to mountain habitats that are poorly suited to solar farms showed little change. "Our findings highlight a critical green dilemma: without meticulous spatial planning, policy-driven solar expansion can inadvertently compromise local biodiversity," the team wrote.
Building solar without the harm
The researchers argue that future photovoltaic development should come with strict biodiversity safeguards, especially in economically developed regions with complex habitats. Siting panels on desert land, degraded land or rooftops could cut the damage, they say. Ken Rosenberg, a conservation scientist at Cornell University who was not involved in the study, cautioned that diversity measures can obscure how a specific local bird population is doing, and he said future work should track population numbers directly.