Rising heat damaging health and economy

New Delhi: Heat and humidity in the tropics have exceeded the safety threshold for outdoor workers involved in heavy labour, specifically in construction, agriculture, fisheries and forestry sectors, reveals a new study.

This has had a negative impact on the health of the outdoor working population and is also inflicting economic loss on the tropics.

The study estimates the cost of lost potential labour productivity for outdoor workers from heat from several hundred billion to over 2 trillion dollars per year. As many as one billion outdoor workers live in the tropics.

If the tropics warms up by an additional 1°C, it would result in nearly 800 million people losing over half of their working hours per year, the study finds. The resultant loss of labour productivity and wages would push outdoor workers into a web of poverty.

The estimated numbers are likely undercounted as it doesn’t factor in informal household work, such as firewood and water collection, and those engaged in informal manufacturing. Nearly 60%–70% of the global labour force participates in the informal economy, with approximately 67% and 90% of workers older than 15 years in informal employment in emerging and developing countries, respectively.

The tropics are defined as the geographic region between 30° latitude north and south of the equator, which includes diverse regions, including dry deserts, coastal regions dotted with mangroves and tropical forests. The region is home to most of the world’s poor.

The study, Impacts of warming on outdoor worker well-being in the tropics and adaptation options published in the One Earth journal, focused on heat impact on worker health, their well-being, productivity and on how to increase resilience to heat for outdoor workers.

The northern limit of the tropics, called the Tropic of Cancer, runs through the middle of India – from the Rann of Kuchh in the west to Mizoram in the east – though the entire country is considered tropical. India is among those tropical regions that already lost one-fifth (20%) of working hours due to humid heat. A further rise in temperature by 1°C would lead to nearly a loss of one-third (33%) of working hours. It means, rising heat would hinder the productive ability of one in eight people living in the tropics.

The study calculated a 10% reduction in physical work capacity with mild heat stress (i.e. wet bulb globe temperature (WBGT), 18°C) and 78% reduction with extreme heat (WBGT 40°C). The WBGT is a measure of heat stress in direct sunlight, which takes into account temperature, humidity, wind speed, sun angle and cloud cover.

Recently, the Indian Meteorological Department forecasted above normal heat wave days and higher than normal temperature in April-June would have a detrimental effect on outdoor workers.