Shocking changes discovered when scientists mapped Earth’s rivers over 35 years

New research shows that over the past 35 years, 44 percent of the largest downstream rivers have experienced massive changes in the amount of water flowing through them each year. The cause of these rapid river changes? Fossil fuel-induced climate change and human activity.

The research was published in the journal Science early December. However, the cause of these changes was not the main focus of the study. Instead, the researchers wanted to focus on the changes themselves. They say rivers like the Congo River in Africa, the Yangtze River in China and even the Plata River in South America have seen major declines over the past three and a half decades.

Previous research on river changes has focused primarily on larger rivers, meaning it only produces results limited to very specific places and times, said Colin Gleason, one of the co- authors of the study. CNN. However, this new study went deeper by simultaneously examining changes in rivers all over the world.

While nearly 50 percent of larger rivers downstream saw differences, Gleason and his colleagues say 17 percent of smaller rivers upstream experienced other drastic changes: an increase in flow. However, overall, the report found that some of the world’s waterways are changing 5 to 10 percent per year, representing “rapid, very rapid change,” Gleason said.

This increase in flow observed in some rivers is also due to climate change, as snow and ice continue to melt. Faster flows can also have positive impacts, moving more nutrients and allowing fish to migrate more quickly. However, not all river changes are good, as these faster flows also worsen sediment transport and can undermine hydropower projects.

From there, Gleason says the next step will be to figure out exactly why the flow of these rivers is changing so quickly and find a way to respond. If we don’t get a good answer, we could continue to see even more drastic changes in the coming years as climate change worsens.