The brown planet? Global warming is literally changing the color of Earth’s water
Author: Jocelyn Solis-Moreira
The next generation may never see a polar bear and, apparently, they may never see blue lakes again as well. A new study from researchers at the American Geophysical Union (AGU) found that if global warming continues along its current path, lakes are likely to shift in color from blue to green-brown. The changing colors are a sign of poor ecosystem health. Lakes change hues for a number of reasons, from algal growth to runoff of sediments. However, the new study finds that other factors such as air temperature, frequency of rainfall, lake depth, and elevation also influence the water’s color. One-third of the world’s lakes are true blue. They are often deep areas in cool, high-latitude regions where it often rains and snows. Green-brown lakes, on the other hand, comprise 69 percent of all lakes and are located along coastlines and other dry regions. The study authors used 5.14 million satellite images from 85,360 different lakes and reservoirs around the world to come to their findings. The photos were taken from 2013 to 2020. Since lake color can change seasonally, the interactive map they drew measured the most frequent lake color over the seven-year span.