New Delhi, March 17 High temperatures caused by climate change could lead millions around the world to become physically inactive by 2050, and be linked to up to 700,000 additional premature deaths annually and $3.68 billion in lost productivity, according to a study published in The Lancet Global Health journal.
Rising temperatures alone could undermine a significant portion of the World Health Organization's (WHO) target of reducing physical inactivity globally by 15% by 2030, researchers from Latin America, including the Pontifical Catholic University of Argentina, said.
India is projected to see a mortality rate attributable to physical inactivity of 10.62 deaths per 100,000 population by 2050 under the three future scenarios analyzed – low emissions, historical trends continuing unchanged, and rapid fossil-fuel-driven development.
Climate change is making the world hotter, and the increasing heat can impact people's ability to be physically active.
A study recently published in the journal Environmental Research Health suggested that in some parts of the tropics and subtropics, hot and humid conditions during the hottest hours of the year limit safe physical activity for both younger and older adults, restricting them to sitting and lying down.
Physical inactivity is already a major global health problem, with about one in three adults failing to meet WHO guidelines for weekly exercise, the researchers said.
The WHO recommends that adults aged 18-64 engage in at least 150 minutes of moderate intensity or 75 minutes of vigorous intensity physical activity per week.
Muscle-strengthening activities involving major muscle groups should be done two or more days a week, it says.
The researchers analyzed data from 156 countries between 2000 and 2022 to model how rising temperatures may affect physical activity globally up to the year 2050.
The model suggests that by 2050, each additional month with an average temperature above 27.8 degrees Celsius would increase physical inactivity by 1.5 percentage points globally and by 1.85 percentage points in low- and middle-income countries.
"By 2050, these increases translate into an additional 0.47-0.70 million deaths and $2.40-3.68 billion in annual productivity losses," the authors wrote.
"Rising temperatures are projected to increase the prevalence of physical inactivity, translating into additional premature deaths and productivity losses, especially in tropical regions," they said.
The implications for global health are immediate, the researchers said.
"Integrating heat-risk messages into exercise guidelines, directing climate finance towards shade-rich active transport corridors, subsidising cooled exercise facilities for at-risk populations, and enforcing robust occupational heat-safety standards are highly cost-effective actions that deliver concurrent public health, urban liveability, and emissions-reduction benefits," they said.
Therefore, physical inactivity needs to be treated as a climate-sensitive necessity, rather than a discretionary lifestyle choice, to prevent a heat-driven sedentary transition and accompanying surge in cardiometabolic diseases and economic losses, the authors said.