When estimating costs that climate change will impose on societies, climate economists face a difficult barrier: They can only incorporate into models well-understood and quantified climate damages. Authors of a recent study published in Nature have identified previously unknown economic impacts associated with changes in rainfall.
While an increase in worldwide rainfall is a known consequence of global warming and of a hotter atmosphere’s holding more water vapor, most prior climate-economics modeling had concluded that this change will have an insignificant impact on economic growth. But by examining daily regional rainfall data, the researchers of the Nature paper found that these previous studies, with their lower-resolution global perspectives, have glossed over some important nuances in how local precipitation patterns will change.
One significant and previously overlooked effect lies in the increase of extreme daily rainfall totals that can disrupt economies by causing local flooding. Precipitation “shocks” like particularly dry months also tend to significantly reduce productivity in a number of sectors. And most subtly, the researchers found that even a seemingly benign effect like an increase in the number of wet days in a particular region can create a drag on that region’s economic growth.
As a result, they concluded, “recent findings are unlikely to realistically capture future costs” associated with climate-changed rainfall. Their paper serves as an important reminder that climate-economics models incorporating only well-understood climate impact likely significantly underestimate costs that climate change will impose on human society.
Shocks to the system and more wet days are drags
Despite the importance of reliable water availability, the authors noted, “most macro-economic assessments of the costs of climate change have found precipitation changes to affect economic growth rates insignificantly.” They…