Developing countries are hardest hit
“The thresholds of heat exposure leading to labour productivity loss are likely to be exceeded sooner and more extensively in developing countries in warmer parts of the world,” says Matthews.
“These countries are also more vulnerable because a higher fraction of their work force is employed in these sectors and because they have less ability to implement infrastructural changes that deal with a changing climate.”
The research suggests that lower-income countries will experience much stronger economic impacts than higher-income countries. Worst hit are tropical areas of the globe such as Southeast Asia, north-central Africa and northern South America.
“The labour productivity loss computed for low- and lower-middle-income countries is approximately nine times higher than the one of high-income countries,” reads the report.
(The authors are also careful to point out that health recommendations are not obligatory and are often not seriously or consistently applied at real-world work sites. Their estimates of productivity loss is based on the strict adherence to health guidelines regarding labour in extreme heat.)
From emissions to impacts
Matthews and his co-authors based their calculations of historical and future increases of heat exposure using simulations from eight separate Earth Systems Models. While many academic studies have estimated socioeconomic impacts of climate change, he says this paper is novel because it predicts future impacts as a direct function of CO2 emissions.
“The relationship between emissions and impact is pretty linear, so we are able to say that this additional quantity of CO2 emissions will lead to this additional increase in impact,” he explains. “The impact scales pretty well with the total amount of emissions we produce.”
Cost of business
The authors write that their research linking CO2 emissions to loss of labour productivity from heat exposure can help countries adopt mitigating measures. But Matthews says it may also help people change their thinking about the overall consequences of a relentlessly warming planet.
“We can see that every additional ton of CO2 emission that we produce will have this additional impact, and we can quantify that increase,” he says. “So this study can help us point to specific countries that are experiencing a quantifiable share of the economic damages that result from the emissions we produce.”
Read the cited paper: “Exposure to excessive heat and impacts on labour productivity linked to cumulative CO2 emissions.”