PNNL

Abstract

Lakes provide unique benefits but are vulnerable to climate change. One of the key physical responses of lakes to climatic variations include a change in their thermal environment. Notably, changes in the timing, intensity, and duration of thermal stratification can have a considerable influence on lakes, as well as the organisms that live within them. Here, we use an ensemble of lake and climate models to simulate lake stratification from 1901 to 2099. We show that stratification events will become more intense and longer lasting by the end of the 21st century. For the high greenhouse gas emission scenario, the average intensity of stratification events will increase by 0.40±0.04 kg m-3 and their average duration will increase by 24.8±2.6 days. Lake stratification phenology is also projected to be influenced by climate change, with the onset of stratification occurring 18.8±7.2 days earlier and stratification break-up occurring 8.7±3.8 days later by 2070-2099. The effects of stratification change will be widespread and extensive, including impacts on aquatic organisms, the ecosystem services that lakes provide, and the production of greenhouse gases within lake sediments.