5 March, 2024

Carl Nasman Washington DC Hello and welcome to Future Earth. When it comes to grand infrastructure, dams are among the grandest. Throughout the 20th Century, hydroelectric dams sprung up across the world's rivers as a source of seemingly unbridled, accessible power. Today, many of those dams are being torn down as countries try to free their rivers' flow and find less ecologically damaging ways to get fossil-fuel-free power. Plus, we learn about the shifting sands that inspired Dune and how climate change in the Arctic is altering the way the Sami speak.   CLIMATE CONVERSATION The demolitions freeing the world's rivers Dam removal is a meticulously planned and lengthy engineering work. Credit: Mikko Nikkinen/Storymakers It was a spectacular sight: water along a portion of the Klamath River in California flowing freely for the first time in more than a century. Spectators cheered as a loud series of controlled explosions prompted a torrent of muddy water to come bursting through the bottom of the Copco 1 dam in January. The controlled detonation was part of history - the United States' largest-ever dam removal project. The Klamath winds 257 miles (414 km) through the rugged mountains of Oregon and California on its way to the Pacific Ocean. But for decades, it has been blocked by four hydroelectric dams. Now, their dismantling is being celebrated by environmentalists - including California Governor Gavin Newsom - and Native American tribes like the Yurok. You can read about the tribe's years-long fight to restore the river and its ancient upstream migration of fish here. The demolitions are emblematic of a larger question facing many communities around the globe: what to do with our aging hydroelectric dams? This old bridge on the Sélune River in Normandy, France, had been submerged before the removal of two large dams between 2019 and 2023. Credit: Observatoire photographique des paysages de la Sélune/Université Paris Nanterre et SMBS The barriers provide fossil-fuel-free electricity at a time when we need it more than ever. But they come with many other environmental problems - not least, blocking the path of migratory fish.  In fact, a recent red list assessment by the International Union for Conservation of Nature (IUCN) warns that a quarter of the world's freshwater fish species are at risk of extinction and nearly half of those threatened are negatively affected by dams and water extraction. But, as Lucrezia Lozza writes for BBC Future Planet, many dams in Europe are approaching the end of their operational life or facing mounting maintenance costs. As a result, some rivers are being returned to their free-flowing states, just like the Klamath. Ebbs and flows Finland recently removed three of its dams after studies showed the electricity production was no longer worth it, compared with the costs of maintenance and mandatory environmental protections, like fish-ladders. Three years ago, when construction workers began demolishing the dams on the Hiitolanjoki River, they were surprised to see a run of wild salmon returning after a long absence. Every time a dam was removed, salmon embraced the new part of the river, extending their habitat further upstream towards their historic spawning grounds. Today, the dams are gone, and the water runs freely once again, through newly built rapids surrounded by tall trees. For some, dam removal can be controversial. As rivers change course and reservoirs are drained, beloved landscapes can change drastically. But dam removal can also be transformative. Restored rivers have become tourism opportunities. At the Hiitolanjoki River, the area is poised to see a significant surge in visitors.  Similarly, in the US, removals have often resulted in people returning to rivers to swim, paddle and watch wildlife. In Maine, returning the Penobscot River to free flow had great cultural importance, with the Penobscot Indian Nation one of the main stakeholders in favour of the dam's removal. As of 2022, nearly two thousand US dams have been removed - a drop in the river, given the nearly 92,000 that still dot the country. And researchers are concerned about the environmental effect of new dams planned in areas like the Amazon, Congo and the Mekong Basin. The race is on to find alternative sources of clean power that can protect both nature and people. Read Lucrezia Lozza's full story on the dams being torn down across Europe. NUMBER OF THE WEEK $7.27 The average cost of a gallon of plant-based milk compared to just $4.21 for cow's milk. Our reporter Lucy Sherriff tested whether she could save moneyby making her own plant-based milk. TAKE A MOMENT Can the Sami language survive in a warmer world? The arctic's indigenous Sami people use highly specific words to describe their unique way of life. But as climate change alters their landscapes, their language is changing too. Read more CLIMATE QUIZ The infrastructure needed to support research in Antarctica requires careful planning and management, but not at the cost of the local wildlife. How many times a day are engineers and construction workers there allowed to move penguins out of the way? A. Once B. Unlimited C. Five times Scroll to the bottom of this newsletter for the answer. THE BIG PICTURE The landscape that inspired Dune "Terraforming" of the sand in Oregon inspired themes in Frank Herbert's Dune. Credit: Nathaniel Scharping In the 1950s Frank Herbert, then a young journalist, visited the coastal area just south of the town of Florence, Oregon. He was intrigued by the vast sand dunes that threatened to overwhelm the nearby settlements, as well as by the scientists attempting to hold back the shifting sands by planting grass. What Herbert saw in Florence went on to inspire his epic sci-novel, Dune, and its fictional desert planet, Arrakis. But while Dune Part Two, the latest film adaptation based on the novel, is now out in cinemas, the real-world ecological challenge that inspired the novel is still far from over. BEFORE YOU GO • Millions of mattresses end up in landfill or are burned in Europe every year. Issuing product passports for items like these could be a way to reduce their environmental impact, BBC technology reporter Sean McManus reports. • The latest edition of The Climate Question podcast explores what it's like being a "Chief Heat Officer" in Sierra Leone. You can also read more about their work in our Climate Guardians series. • A 385-million-year-old forest in Cairo, New York, may hold clues to the evolution of ancient forest ecosystems and early climate changes. BBC Travel reports. US Election Unspun newsletter Cut through the noise in the race for the White House, every Wednesday to your inbox. Sign up here MORE BBC NEWSLETTERS • Tech Decoded: Timely, trusted tech news from global correspondents, twice-weekly. Subscribe. • Royal Watch: The full story from royal correspondent Sean Coughlan, every Thursday. Subscribe. • Football Extra: Latest news, insights and gossip from the Premier League, weekdays. Subscribe. AND FINALLY... The humble lentil can pack a protein-punch, at 25% of the legume's total calories. In the ancient Middle East, they provided one of the main sources of dietary protein and were far more important for most people than animal products. Today, as scientists and governments call on people to eat less meat as a way to reduce their climate impact, the protein-rich lentil has much to offer once again. Veronique Greenwood explores the history of this under-celebrated legume. Today's climate quiz answer was C: Those undertaking construction work in Antarctica can only move wildlife, including penguins, a maximum of five times per day. "This is their home, not ours. They take priority over anything else," says Maria Gonzalez Rico, an associate at the engineering firm Ramboll and lead designer on the modernisation of Adelaide Island's Rothera airstrip, which helps support both biological and climate research. Katherine Latham reports on the challenges these workers face in the coldest place on Earth. Thank you for reading this edition of Future Earth, which was edited by Martha Henriques India Bourke and Richard Gray. Got feedback? You can reach us by emailing here. We’ll be back in your inbox next Tuesday. In the meantime, you can follow the best of BBC climate and sustainability coverage here.