Rainfall changes caused by global warming will increase river flooding risks across the globe by the 2040s, says a new study.

A team of scientists conducted an unprecedented health check of the entire Hudson River system, from its source to New York Harbor. This is what they found.

Researchers from eight universities, including Columbia University, are using tree ring and glacier analysis to reconstruct the climate history of the Missouri River Basin in order to give policymakers and water managers better decision-making tools to manage the river.

To protect a river, you must preserve its headwaters. Agricultural development is warming streams at the headwaters of the Xingu River, in Mato Grosso, Brazil. Rising temperatures have local impacts that could cascade into regional changes, highlighting the importance of responsible land use outside of protected areas.

In the summer of 1969, legendary folk musician and activist Pete Seeger headed a grassroots campaign to clean up the polluted Hudson River. At the heart of that campaign was a replica of a 200-year-old sailing ship– the sloop Clearwater. Nearly 50 years later, Clearwater remains an emblem of environmental reform. But with Seeger’s death at age 94 this past January, what will become of his cause?

The upper Delaware River Basin System is one of the largest water supply systems for the city of New York. Today our understanding and management of these reservoir systems is based on the short historical records of data, which are limited. Scientists need to find a way to look further into the past. One of the answers lies in tree rings.

As we finally reached our prime target area, it was time for me to leave the ship and return home. Despite initial struggles on navigating the Brahmaputra River, we have worked together with the ship’s crew and pilots for a successful method. And now as I leave with many new friends, the best data is coming in.

Rejoining the ship, we sailed up the Padma and Jamuna (Brahmaputra) Rivers. Hurrying to our primary area with the help of pilots, we finally collected good seismic data.

Finishing up in the muddy rivers of NE Bangladesh, we headed downstream to switch to the mighty Brahmaputra River system. However, on the way down I had to jump ship to go into traffic-clogged Dhaka for some meetings before rejoining her on the Padma, the name of the combined Ganges and Brahmaputra Rivers.

At any given time, there are dedicated environmentalists around the U.S. working to protect our waterways.These “keepers” are all members of the Waterkeeper Alliance (WKA), an organization of over 200 keepers globally, defending their communities’ rights to clean water.