Centennial model shows a significant increase in lake heat waves at the end of this century.
A recent study of climate science models published in the British journal Nature shows that by the end of the 21st century, the intensity and duration of lake heat waves (the period when the water temperature is extremely hot on the lake) will increase.
In the scenario of high greenhouse gas emissions, the average duration of lake heat wave may increase by about three months, and some lakes may enter a permanent heat wave state, accompanied by the resilience of the ecosystem may approach the limit.
The increased frequency of heat waves on the land and ocean surfaces is believed to be related to global warming.
However, there is still a cognitive gap about the lake heat wave and how it is affected by global warming.
Lake ecosystems are very sensitive to temperature changes, and lakes’ response to global warming can also affect organisms that depend on these environments.
In view of this, Esstern Walway, the Climate Office of the British European Space Agency, and his colleagues simulated the impact of the heat wave on 702 lakes from 1901 to 2099.
They found that under the high greenhouse gas emission scenario (RCP 8.5), by the end of the 21st century, the average warming of the lake heat wave may increase from about 3.7 °C to about 5.4 °C, and the average duration will be increased from about 1 week to more than 3 months.
Under the most conservative emission scenario (RCP 2.6), the average temperature rise duration is about 4.0 °C and 1 month, respectively.
The team’s predictions include lakes up to 60 meters deep.
They found that the heat wave in deeper lakes lasts longer but is weaker.
The research team believes that as the lakes gradually warm up in the 21st century, the heat wave will cover all seasons, and some lakes will enter a permanent heat wave state.
Walway concluded that the increase of heat wave events or threaten the biodiversity of lakes, causing the resilience of ecosystems to approach the limit.
In 2019, another report published in Nature · Climate Change also showed that global warming is increasing the average temperature of the sea system.
The study found that heat waves are becoming more frequent and duration, and the number of heat waves in global ocean systems has tripled in the past few years.
In the long run, the number of heat wave days increased by more than 50% in the 30-year period up to 2016 compared with 1925-1954. More importantly, with the increase of heat waves, seaweed forests, seagrass beds and coral reefs are gradually disappearing.
