A new study led by Vrije University Brussel (VUB) has found that climate change severely affects lakes all over the world. According to the research team, global changes in lake temperatures and ice cover are not caused by natural climate variability and can only be explained by the massive greenhouse gas emissions that started with the Industrial Revolution.
At the beginning of their project, the scientists observed that lake temperatures are gradually rising and the seasonal ice cover is shorter worldwide. “This is very convincing evidence that climate change caused by humans has already impacted lakes,” said study lead author Luke Grant, a doctoral student at VUB.
In a second step, they developed multiple computer simulations with which they predicted future developments under different global warming scenarios. In a low greenhouse gas emission scenario, the average warming of lakes is estimated to stabilize at +1.5 degrees Celsius above pre-industrial levels and the duration of ice cover to be 14 days shorter. On the other hand, in a high-emission scenario, lake temperatures could increase by 4 degrees Celsius and they could have 46 fewer days of ice.
The scientists concluded that for every degree Celsius increase in global air temperatures, lakes are estimated to warm by 0.9 degrees Celsius and lose 9.7 days of ice.
“These physical properties are fundamental to lake ecosystems,” explained Grant. “As impacts continue to increase in the future, we risk severely damaging lake ecosystems, including water quality and populations of native fish species. This would be disastrous for the many ways in which local communities depend on lakes, ranging from drinking water supply to fishing.”
“Our results underline the great importance of the Paris Agreement to protect the health of lakes around the world,” added study senior author Wim Thiery, a climate expert at VUB. “If we manage to drastically reduce our emissions in the coming decades, we can still avoid the worst consequences for lakes worldwide.”
The study is published in the journal Nature.