Luke Grant from the Free University of Brussels is the main author of the paper. He said: “These physical properties are the foundation of the lake ecosystem. As the impact continues to increase in the future, we may severely damage the lake ecosystem, including water quality and local fish species. The number. This would be disastrous for the many ways local communities rely on the lake, such as drinking water supply and fishing.”
The research team also predicted how things might develop in the future under different warming conditions.
The figure above shows that in the case of low emissions, the average temperature rise of the lake is estimated to stabilize at 1.5°C higher than the pre-industrial level, and the duration of the ice surface will be shortened by 14 days. In a high-emissions world, these changes could cause lake temperatures to rise by 4.0°C and reduce the number of freezing days per year by 46 days. At the beginning of the project, the author observed changes in lakes around the world based on satellite-derived observations of the ESA Climate Change Initiative Lakes Project, as described in the images of Lake Ontario.
However, the role of climate change in these trends has not been proven. “In other words, we must rule out the possibility that these changes are caused by natural changes in the climate system,” said Inne Vanderkelen, a researcher at the Free University of Brussels and co-author of the research report.
Therefore, the research team conducted multiple computer simulations with global lake models, and then ran a series of climate models on this basis. The team then established this database, using the method described by the Intergovernmental Panel on Climate Change. After determining the historical impact of climate change on the lake, they also analyzed various future climate scenarios.
The results show that the trend of lake temperature and ice cover in recent decades is extremely unlikely to be fully explained by changes in natural climate. In addition, the researchers found clear similarities between the observed lake changes and the lake model simulations in climates affected by greenhouse gas emissions.
Iestyn Woolway, a former ESA researcher and co-author of the study, said: “This is clear evidence that climate change caused by human activities has an impact on lakes.” The predictions of lake temperature and ice levels consistently indicate future growth trends.
The researchers said that for every 1 degree Celsius increase in global air temperature, the lake is estimated to heat up by 0.9 degrees Celsius, and the number of freezing days will decrease by 9.7 days. In addition, analysis shows that the impact on lakes at the end of this century varies greatly, depending on the measures we take to deal with climate change.
“Our results underscore the great importance of the Paris Agreement in protecting the health of lakes around the world,” said Wim Thiery, a climate expert at the Free University of Brussels and senior author of the study. “If we manage to drastically reduce our emissions in the next few decades, we can still avoid the worst consequences for the world’s lakes.”