Limited Effect of Future Land-Use Changes on Human Heat Stress and Labor Capacity
- Rafal Tekreeti
- May 19
- 2 min read
By: Steven J. De Hertog, Anton Orlov, Felix Havermann, Suqi Guo, Iris Manola, Julia Pongratz, Quentin Lejeune, Carl-Friedrich Schleussner, Inga Menke, Florian Humpenöder, Alexander Popp, Peter Lawrence, George C. Hurtt, Louise Chini, Inne Vanderkelen, Edouard L. Davin, Thomas Reerink, Sonia I. Seneviratne, Hans Verbeeck, Wim Thiery.
When we think about climate change, we usually focus on burning fossil fuels, but what we do with land can also heat up or cool down the planet. Future land use trajectories are crucial to achieve the Paris agreement climate targets. Not only because of the crucial role of forests, which take up carbon dioxide and thus mitigate climate change, but also through how they affect how much sunlight and water heat the air, which directly affects local temperatures, humidity, and wind patterns. These local climate changes can affect heat stress on a regional to local scale. This also reduces how much outdoor work people can do, which can have economic impacts, especially in already hot and vulnerable regions. But heat stress isn't just about temperature – it’s also about humidity and wind, which land use changes influence. This means simply looking at average temperature isn't enough: we have to understand the full picture of how land use affects human well-being.
Here we studied heat stress in future climate simulations using Earth System Models. By running three different models under different land use futures (see Figure 1 illustrating the “sustainability future” and “inequality future”). Our results show that even if we cut fossil fuel emissions enough to meet the Paris Agreement goals (keeping warming below 1.5°C or 2°C), land use change (LUC) could still tip the scales (Figure 2). Big differences show up between a world where we protect and restore forests (the "sustainability future") and one where we clear more forests for farming (the "inequality future"). However, the exact warming levels differ across the different models. With two models surpassing the global climate targets of the Paris agreement in the inequality future.
However, these clear effects on global mean temperature don’t always translate to reduced effects in heat stress. Our results show that while better land management can slightly cool the planet, its impact on reducing heat stress locally, especially in the tropics, are more uncertain and limited. Sometimes, even if land use brings temperature cooling, changes in wind and humidity cancel out the benefits exactly when they’re most needed — during extreme heat. This is especially important for the impacts of outdoor worker productivity, as these extreme heat events are the most impactful. Different models disagree on the sign of change, especially for impacts on outdoor worker productivity.
Future work needs to address this uncertainty by improving the models, finding better ways to measure heat stress, and taking a broader view beyond just labour losses, because heat also impacts health, crops, ecosystems, and economies.
Read the full article in Wiley/AGU Publishing here
