Human Impact on Freshwater Ecosystem Services: A Global Perspective

TLDR

Human environmental change affects freshwater ecosystems and their regulating, provisioning, and cultural services worldwide. The study evaluates the global human impact on the potential value of six freshwater ecosystem services and estimates the proportion of each used worldwide. The authors assessed global human impact by estimating the proportion of potential value used for six freshwater ecosystem services and constructed a composite impact index. Humans have used roughly 4–20% of the potential global freshwater ecosystem services, with a median of 16%, and all countries use a considerable amount, disproving the notion that wealthier nations have less impact, while high population growth rates are linked to greater degradation.

Abstract

Human environmental change influences freshwaters as well as the regulating, provisioning, and cultural services that ecosystems provide worldwide. Here, we assess the global human impact on the potential value of six freshwater ecosystem services (ES) and estimate the proportion of each used globally (the mean value across all countries is in parentheses): biodiversity (0.37), disturbance regulation (0.24), commodities (0.39), greenhouse gases (0.09), water availability (0.10), and water quality (0.33). We also created a composite index of the impact. Using different valuation schemes, we found that humans have used potential global freshwater ES scaled by a relative value of roughly 4–20%, with a median of 16%. All countries use a considerable amount of the potential ES value, invalidating the idea that wealthier countries have less impact on their ES once they have developed. The data suggest that humans have diminished the potential ES provided by freshwaters across the globe and that factors associated with high population growth rates are related to the overall degradation.