From oceans to land, water is where we’re seeing the human impact the most in my opinion. We’re also seeing that fluctuations in the planet’s freshwater streams, ponds, and other surface features are minor compared to the changes occurring in dammed-up reservoirs. Natural fluctuations between wet and dry seasons are only about 8.6 inches while human-managed water features fluctuate by 2.8 feet. This is a three-fold difference, and this global average hides the nation-to-nation variability. 

In places like the U.S., southern Africa, and the Middle East, where dams are used frequently, variations may be as much as 6.5 feet to 12.4 feet. These kinds of changes aren’t something our environment is adapted to handle, and according to study lead author Sarah Cooley, “There are a lot of ways in which this is bad for the environment,” ranging from harm to fish populations to potential increases in emissions of methane, a potent greenhouse gas.

Water is at the heart of life as we know it here on earth, and as we change our planet, we change our water, which just might make it a bit harder for everything to live.

More Information

Stanford University press release

NASA Goddard press release

“Human alteration of global surface water storage variability,” Sarah W. Cooley, Jonathan C. Ryan, and Laurence C. Smith, 2021 March 3, Nature