In an interview with the South China Morning Post in early September, Chen Renjie, co-author of the study and a professor at Fudan University, said the measures should be part of a collaborative effort between the health sector, the government and other social organisations.
“This is essential to ensure [people’s] health and well-being.”
The study was published in the peer-reviewed journal JAMA Psychiatry in March and conducted by researchers from Fudan University and the Chinese Centre for Disease Control and Prevention.
The authors used data from 432,008 suicide deaths occurring between 2013 and 2019 across mainland China, with the information collected from the China Cause of Death Reporting System, the most representative national death registry in China.
Then they used climate projections from global climate models and predicted temperature-related suicide deaths through to 2099.
The researchers found that more than 65,000 suicide deaths in China between 2013 and 2019 were associated with “non-optimal temperature”, meaning temperature above the theoretical minimum-risk exposure level. That accounted for 15 per cent of the total suicide deaths during that time period.
The authors predicted that climate warming could result in an additional 24,000 suicides in China in the 2090s under the high-emission scenario, compared to the historical period between 1980 and 2009.
Nationally, compared with the historical period, excess suicide deaths would increase by 11.4 per cent in the 2050s and 21.7 per cent in the 2090s under the high-emission scenario, the study said.
“We projected that the excess suicide deaths will increase with the warming climate, characterised by a consistent and drastic increase over this century under the high-emission scenario,” the authors wrote in the study.
The authors did not say how hotter temperatures could increase the suicide risk level.
Gao Ya, lead author of the study and a PhD candidate at Fudan University, said the percentage increments of excess suicide deaths would be high in winter because the baseline was low and people tended to be more sensitive to unusually high temperatures in winter. Also, the climate warming may be more evident in winter than in other seasons.
The study is consistent with previous studies in other nations. In a 2018 study in the journal Nature Climate Change, researchers from the US, Canada and Chile found that temperature increases through to 2050 could lead to an additional 21,000 suicide deaths in the US and Mexico.
“The study highlights the potential threat to people’s mental health caused by climate change, and it provides key information for developing coping strategies,” Gao said.
“It also suggests that we need to include mental health in climate change adaptation strategies. Governments, the health sector and social organisations should provide more support, including mental health services, to help the vulnerable populations adjust to climate change.”