Eutrophication of lakes will significantly increase greenhouse gas emissions

What's wrong with being green? Toxins released by algal blooms can ruin drinking water. When dense algae blooms die, the bacteria that decompose the algae also deplete oxygen in the water. Without oxygen, fish and other animals suffocate. Globally, such green waters are also an important contributor to atmospheric methane -- a greenhouse gas that is up to 34 times more potent than carbon dioxide.

"We estimate that the greening of the world's lakes will increase the emission of methane into the atmosphere by 30 to 90 percent during the next 100 years," said Jake Beaulieu of the United States Environmental Protection Agency and lead author of a paper on lake greening and greenhouse gas emissions published March 26, 2019 in the journal Nature Communications.

According to the authors, three distinct mechanisms are expected to induce increases in lake greening or eutrophication during the next 100 years. First, human populations are expected to increase by 50 percent by 2100. More people means more sewage and more fertilizers that runoff land. At current rates of population growth and climate change, eutrophication in lakes will increase by 25 to 200 percent by 2050 and double or quadruple by 2100.