Lakes as sentinels of climate change

TLDR

Lakes are considered potential climate change sentinels, yet their effectiveness remains under‑examined and can be confounded by eutrophication, acidification, and land‑use changes. Analytical tools such as detrending or filtering can address confounding factors. The study identified a suite of physical, chemical, and biological lake variables that serve as climate change indicators, noting that their effectiveness varies with regional climate response, catchment traits, and mixing regimes, and that lakes are effective sentinels due to their sensitivity, rapid response, and integration of catchment changes.

Abstract

While there is a general sense that lakes can act as sentinels of climate change, their efficacy has not been thoroughly analyzed. We identified the key response variables within a lake that act as indicators of the effects of climate change on both the lake and the catchment. These variables reflect a wide range of physical, chemical, and biological responses to climate. However, the efficacy of the different indicators is affected by regional response to climate change, characteristics of the catchment, and lake mixing regimes. Thus, particular indicators or combinations of indicators are more effective for different lake types and geographic regions. The extraction of climate signals can be further complicated by the influence of other environmental changes, such as eutrophication or acidification, and the equivalent reverse phenomena, in addition to other land‐use influences. In many cases, however, confounding factors can be addressed through analytical tools such as detrending or filtering. Lakes are effective sentinels for climate change because they are sensitive to climate, respond rapidly to change, and integrate information about changes in the catchment.