News & Events

19 april 2021

Phenological shifts in lake stratification under climate change

New observations & model-based study examines changes in lake stratification under climate

A new analysis of the impacts of climate change on lake ecosystems is published today in Nature Communications. It uses the long-term records of lake surface temperature and ice cover produced by the ESA CCI Lakes team. The study is led by ESA fellow Iestyn Woolway, based at the ESA Climate Office.

The study finds that lake “stratification periods” – a seasonal separation of water into layers – will last longer in a warmer climate. These longer periods of stratification could have “far-reaching implications” for lake ecosystems, the paper says, and can drive toxic algal blooms, fish die-offs and increased methane emissions.

The authors examine historical changes in lake stratification periods in the northern hemisphere using the CCI Lakes data and daily simulations from a collection of lake models. They ran simulations of future changes in lake stratification period under three different emission scenarios, to determine how stratification could change in the future.

They find that the average seasonal lake stratification period in the northern hemisphere could last almost two weeks longer by the end of the century, even under a low emission scenario. And that stratification could last over a month longer if emissions are extremely high. A longer article about the study has been published by Carbon Brief here.


Woolway, R.I., Sharma, S., Weyhenmeyer, G.A. et al. Phenological shifts in lake stratification under climate change. Nat Commun 12, 2318 (2021).