China solar boom linked to bird diversity loss

China's rapid solar energy expansion has been linked to a decline in bird diversity, according to a study across more than 2,300 counties published in Science on Thursday.

The research examined solar expansion policies across 2,344 Chinese counties from 2014 to 2023 and paired them with citizen science bird records. The authors said stronger pro-solar policies were consistently associated with lower bird biodiversity, though the effect was moderate.

Using a policy strength index from 0 to 15.5, the study found that a four-point increase was linked to a 2% decline in the Shannon index, a standard measure of species variety. The researchers said rapid land conversion was the main factor, especially the conversion of cropland and grassland into developed areas.

The study said effects were stronger in wealthier and non-desert regions. Resident and migratory birds both showed significant declines, while species native to mountain habitats poorly suited to solar farms were not affected.

China aims to achieve carbon neutrality before 2060. By 2024, its solar footprint had reached an estimated 4,520 square kilometres, about the size of Rhode Island.

The researchers said solar locations in China are influenced by government Five-Year Plans that promote economic development in selected regions. They said the expansion was accompanied by what they called “inferior greening”, where vegetation cover may increase but ecological quality falls because plant cover is too uniform.

First author Huiming Zhang of the Nanjing University of Information Science & Technology told AFP the aim was not to slow the renewable energy transition, but to make solar development more ecologically informed.

Yuanning Liang of Peking University wrote in a related commentary that birds are useful for large-scale biodiversity assessment because abundance data across time and space is relatively available. She said similar concerns could apply to other renewable energy projects, including wind farms.

The authors recommended steering large solar projects toward places with lower ecological conflict, carrying out stronger site assessments and limiting land conversion in productive, habitat-rich regions.