Rising temperatures linked to climate change could push millions more adults worldwide into physical inactivity by 2050, contributing to hundreds of thousands of premature deaths and billions of dollars in lost productivity, according to a modelling study published in The Lancet Global Health. The findings highlight how environmental change may increasingly shape everyday health behaviours, with far-reaching consequences for population health and economic stability.
As global temperatures climb, heat exposure is expected to make it more difficult for people to remain physically active, particularly in already warm regions. Physical inactivity is already a major public health concern, with roughly one in three adults failing to meet recommended levels of weekly exercise set by the World Health Organization. The study suggests that worsening climate conditions may further compound this challenge, potentially reversing progress in global health promotion efforts.
The research analysed data from 156 countries spanning 2000 to 2022 to estimate how rising temperatures could influence physical activity patterns through to 2050. According to the model, each additional month with an average temperature above 27.8°C could increase global physical inactivity by 1.5 percentage points, rising to 1.85 percentage points in low- and middle-income countries. No consistent effect was observed in high-income countries, possibly reflecting greater access to climate-controlled environments and infrastructure that supports activity despite extreme weather.
These projected shifts in behaviour carry substantial health and economic implications. The study estimates that an increase in inactivity linked to rising temperatures could result in approximately 470,000 to 700,000 additional premature deaths annually by mid-century. In parallel, reduced physical activity is expected to translate into productivity losses of between US$2.40 billion and US$3.68 billion each year, underscoring the broader societal costs associated with climate-driven health risks.
The greatest increases in inactivity are expected in regions that are already hot, including Central America, the Caribbean, Eastern Sub-Saharan Africa, and equatorial areas of Southeast Asia. In these settings, inactivity could rise by more than four percentage points for every additional month above the temperature threshold. However, the authors caution that these findings are based on modelling and rely in part on self-reported activity data, while focusing solely on temperature rather than other climate-related factors. As such, there remains uncertainty regarding the precise scale and distribution of real-world impacts.
Despite these limitations, the study points to the need for proactive measures to mitigate the health effects of rising heat. Suggested strategies include designing cooler urban environments, expanding access to affordable, climate-controlled spaces for exercise, and providing clear public guidance on staying active and safe during extreme heat events. At the same time, the authors emphasise the importance of addressing the root cause by reducing greenhouse gas emissions, recognising that climate change is increasingly intertwined with global patterns of health and wellbeing.
More information: Christian García-Witulski et al, Effects of climate change on physical inactivity: a panel data study across 156 countries from 2000 to 2022, The Lancet Global Health. DOI: 10.1016/S2214-109X(25)00472-3
Journal information: The Lancet Global Health Provided by The Lancet
