Heat-related losses in worker productivity add an estimated $41 to the economic damage caused by each additional ton of carbon dioxide emitted in 2025, according to a Nature Climate Change study. The estimate places a cost that is often left out of climate models alongside better-known damages from heat, crops and energy use.
The figure is not a fee charged when a ton of carbon dioxide enters the atmosphere. It is the modelled present value of future output losses associated with the extra warming from that ton. The authors put a 90% confidence interval around the estimate of $1 to $108, showing how much remains uncertain about future warming, work patterns and adaptation.
Frances C. Moore of the University of California, Davis, and colleagues combined climate projections, occupational exposure and an economy-wide model. Their analysis uses wet-bulb globe temperature, or WBGT, which combines temperature, humidity, wind and radiant heat to describe the strain imposed on a working body more fully than an ordinary thermometer reading.
Heat reduces the capacity for physical work
In hot and humid conditions, the body has more difficulty shedding heat. Workers doing strenuous jobs may need slower work rates, more breaks or a different shift pattern. The effects are clearest in agriculture, construction and other outdoor activity, but indoor staff can also be exposed where cooling is limited.
Countries do not face the same risk. The study locates a large share of damages in South Asia, East Asia, Southeast Asia and Africa, where high heat exposure often overlaps with a larger share of physically demanding work and less widespread access to cooling.
That distribution makes heat a business and development issue as well as a public-health issue. Lost output can appear through fewer productive hours, disrupted schedules, lower physical capacity and spending on cooling or workplace changes.
A higher labor estimate, a lower agriculture estimate
The $41 labor estimate becomes more revealing beside the study’s other revisions. The authors updated their estimate of climate-related agricultural damage from $95 to $29 per ton using evidence assessed in the IPCC’s Sixth Assessment Report.
With both changes included, the model’s expected social cost of carbon for 2025 emissions fell from $204 to $179 per ton in 2020 US dollars, using the paper’s 2% near-term discount rate. The research therefore does not simply add a new damage category to an unchanged total. It reallocates part of the estimated cost from agricultural losses to labor losses.
Social-cost estimates are sensitive to assumptions about future emissions, incomes, temperatures, adaptation and the rate used to put a value on future damage today. The authors’ central result should be read as a rigorous model estimate, not an exact price for every country or employer.
Workplace adaptation has costs and benefits
Employers can respond with shade, water, cooled rest areas, more breaks and schedules that avoid the hottest parts of the day. The US Occupational Safety and Health Administration recommends such controls as exposure rises.
Those measures can protect health and reduce disruption, while carrying their own costs. Air conditioning uses capital and electricity. Earlier shifts affect staffing and logistics. Extra rest can reduce immediate working time, though it may help staff remain productive and avoid dangerous heat strain over a full shift.
Our recent coverage of extreme heat and workplace time examined a separate US study that measured activity rather than output. The new research asks a wider question: how those kinds of heat constraints flow through whole economies when companies, consumers and trade adjust.
As heat exposure rises, physical work capacity may become a more visible factor in investment decisions, working hours and the economic cost assigned to emissions.
