Go with the flow: How to squeeze water from fog, and why to remove a dam
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Removals of small dams are restoring rivers across the Northeast U.S.
Though smaller than those found in the West, more than 31,000 dams from Maryland to Maine nevertheless block fish migration and degrade waterways.
American Rivers, an environmental nonprofit, estimates that 85% of U.S. dams – many built in the 19th century to support manufacturing – are unnecessary. Studies have found that removing dams can boost fish passage, improve water quality, and build watershed resilience. After a dam comes down, “We generally see streams recover to a point where we didn’t even know there was a dam there,” said Jeremy Dietrich, an ecologist.
Why We Wrote This
In our progress roundup, humans reverse the damage from small dams across the United States, make changes to coexist with snow leopards in Nepal, and harvest fog in Chile for benefits with no downside.
Safety advocates have designated April as a month for awareness of low-head dams and their dangerous currents, which contribute to 50 drownings a year in the United States. With support of the 2021 Bipartisan Infrastructure Law, two dozen dams were removed in the Northeast in 2023, and 80 were removed across the country.
Sources: Yale Environment 360, American Rivers, Association of State Dam Safety Officials
Harvesting clouds of fog could provide a water source for dry cities
Fog harvesting is a passive approach to obtaining fresh water: When clouds pass through a mesh panel hung between poles, water droplets form and are channeled into pipes and storage tanks.
New research estimates that mesh equaling 17,000 square meters (4.2 acres) could generate 300,000 liters (79,252 gallons) of water per week – equivalent to the amount currently trucked into the urban slum areas of the Atacama Desert, where the study took place. Just 110 square meters of mesh could supply enough water to irrigate a city’s green spaces for a year.
While Chile’s long coastline and mountains provide many opportunities for fog harvesting, at least 13 other countries use fog collectors. Researchers say that for decades almost half of all socioenvironmental conflicts in Chile were directly related to water issues. Scientists are currently working on a “fog harvesting map” of the country.
Sources: BBC, Frontiers in Environmental Science
Law to keep products out of the European Union that have caused deforestation is phased in
Globally, agriculture is the single largest driver of deforestation, and efforts to halt tree clearing through voluntary methods have largely failed. By mid-2026, exports and imports of products such as coffee, cattle, and cocoa must be sourced from places that are deforestation-free.
The EU aims to finish by June its “country risk benchmarking,” which requires the bloc to assign risk levels to countries based on the prevalence of deforestation. Both customs officials and EU companies must apply rigorous checks on products from higher-risk countries.
The 2023 law also mandates that products sold in the EU be sourced without violating the laws of their home countries. Similar requirements in the past have driven producer countries to strengthen and clarify protections against deforestation.
Sources: Human Rights Watch, World Resources Institute
In Sub-Saharan Africa, how women’s education influences family size
Policymakers may use population projections for a variety of purposes, from planning social welfare programs to preparing for climate change. That’s especially relevant for sub-Saharan Africa, which is expected to double its population by 2100.
The recent analysis examined data from more than 1 million women across 39 African countries between 1986 and 2022. While demographers have long observed that more-educated women tend to have fewer children, the paper found that a woman’s fertility rate is influenced not only by her personal education attainment, but also by the education level of the women around her.
The researchers said they hope that the new data will help design family planning programs, which women’s rights advocates argue are essential for gender equality.
Sources: Semafor, PNAS
A win-win for snow leopards and rural communities
Predator-proof corrals and modest tourism are reducing livestock loss and retaliatory killings of the vulnerable cats.
In Nepal, women are often responsible for the herds while men travel for trade. Women are constructing enclosures with roofs of wire mesh – one model used in the region that is working. While poaching and a loss of natural prey also contribute to the snow leopard’s decline, communities are working to foster peaceful coexistence between herders and wildlife.
Tsewang Namgail, the director of the Snow Leopard Conservancy India Trust, said rural households have come to see the value of hosting tourists in their homes. “In places where snow leopards killed livestock on a day-to-day basis, the same areas have developed tourism, which is bringing in 10 times more than they had earned from rearing livestock,” Dr. Namgail explained.
In January, a large study using six years of camera-trap data from the Tibetan Plateau yielded a count of 1,002 snow leopards – 11% to 21% of the global total.
Sources: BBC, Biodiversity and Conservation, Sixth Tone
