Population growth and climate change over the next century will lead to a major rise in the number and severity of algae blooms in the world’s lakes, increasing global methane emissions by 30 to 90 percent, according to a new study led by the U.S. Environmental Protection Agency.

The study, published in the journal Nature Communications, examined the impacts of global population growth (an estimated 50 percent by 2100), climate change-induced flooding and runoff, and rising global temperatures on nutrient levels in the world’s lakes. It found that the extra sewage, fertilizers, and other nutrients entering waterways will increase the eutrophication of the world’s lakes by as much as 200 percent by 2050, then double or quadruple by 2100.

“It is really surprising how much eutrophication could increase in the next 50 to…