Estimating population heat exposure and impacts on working people in conjunction with climate change

Abstract

Increased environmental heat levels as a result of climate change present a major challenge to the health, wellbeing and sustainability of human communities in already hot parts of this planet. This challenge has many facets from direct clinical health effects of daily heat exposure to indirect effects related to poor air quality, poor access to safe drinking water, poor access to nutritious and safe food and inadequate protection from disease vectors and environmental toxic chemicals. The increasing environmental heat is a threat to environmental sustainability. In addition, social conditions can be undermined by the negative effects of increased heat on daily work and life activities and on local cultural practices. The methodology we describe can be used to produce quantitative estimates of the impacts of climate change on work activities in countries and local communities. We show in maps the increasing heat exposures in the shade expressed as the occupational heat stress index Wet Bulb Globe Temperature. Some tropical and sub-tropical areas already experience serious heat stress, and the continuing heating will substantially reduce work capacity and labour productivity in widening parts of the world. Southern parts of Europe and the USA will also be affected. Even the lowest target for climate change (average global temperature change = 1.5 °C at representative concentration pathway (RCP2.6) will increase the loss of daylight work hour output due to heat in many tropical areas from less than 2% now up to more than 6% at the end of the century. A global temperature change of 2.7 °C (at RCP6.0) will double this annual heat impact on work in such areas. Calculations of this type of heat impact at country level show that in the USA, the loss of work capacity in moderate level work in the shade will increase from 0.17% now to more than 1.3% at the end of the century based on the 2.7 °C temperature change. The impact is naturally mainly occurring in the southern hotter areas. In China, the heat impact will increase from 0.3 to 2%, and in India, from 2 to 8%. Especially affected countries, such as Cambodia, may have losses going beyond 10%, while countries with most of the population at high cooler altitude, such as Ethiopia, may experience much lower losses.

Methods for Estimating Wet Bulb Globe Temperature From Remote and Low‐Cost Data: A Comparative Study in Central Alabama

“…These results are particularly interesting when we consider losses in work capacity and labor productivity due to heat stress. For example, Kjellstrom et al (2018) has estimated substantial losses by the end of the century, mostly due to impacts in the southeastern United States, where heat stress already limits work capacity.…”

Escalating environmental summer heat exposure—a future threat for the European workforce

“…Exposure-response relationships are usually established between hourly heat exposure and productivity (e.g. WBGT above 31°C under moderate work implies 25% reduction of labour productivity in one hour for specific epidemiological studies, Kjellstrom et al 2018). We approximated hourly values with daily mean and maximum WBGT values following the 4 + 4 + 4 method (Kjellstrom et al 2018), which is a good approximation compared to more complex and computationally intense temperature models (Bilbao et al 2002).…”

“…Also, future heat waves are very likely to be more frequent and longer-lasting (IPCC 2013), mainly as a direct consequence of the increase in mean temperatures (Schär, et al 2004;Fischer and Schär 2010). Those changes relate to increasing environmental heat exposure throughout the twenty-first century (Willett and Sherwood 2010;Zhao et al 2015;Knutson and Ploshay 2016;Coffel et al 2018;Li et al 2018;Matthews 2018) which in turn might have an effect on mortality, well-being and labour productivity (Dunne et al 2013;Kjellstrom et al 2018;Mora et al 2017;Flouris et al 2018;Levi et al 2018;Moda et al 2019). The combination of environmental heat exposure and internal heat production generated from metabolic processes results in heat stress (Xiang et al 2014).…”

Impact of climate and air pollution on acute coronary syndromes: an update from the European Society of Cardiology Congress 2017

“…loss of productivity and increased medical costs, remain highly uncertain, but suggest high numbers and potentially very high costs. This is particularly the case for tropical regions [17][18][19][20][21].…”