2 April, 2024

Lucy Sherriff Los Angeles, US Hello and welcome to this week's Future Earth. Recently I spent some time in Miami and was lucky enough to see a manatee – or "sea cow" as they're affectionately known. It was a rare sight, I was told. Scientists describe what's happened to Florida's manatees as one of the "greatest human-wildlife conundrums ever". Their survival is, perplexingly, linked to Florida's legacy power plants; can they survive the state's transition to clean energy? Plus, climate change is tweaking timekeeping and owning up to your e-waste "drawer of doom".

CLIMATE CONVERSATION  The manatees hooked on coal power A manatee and her calf float in Florida's waterways. Credit: Save the Manatee Club I stood on the railings to peer down into the pool as Gerry tossed another head of crisp romaine lettuce to the giant creatures floating below. It landed with a satisfying splat, joining the other bobbing green salad that floated in the small hexagonal pen, ready to be gobbled up by the three dark grey manatees. Their barnacled leathery skin sported large, deep gashes – made by run-ins with boat propellers. Gerry, who has volunteered at Florida's Homosassa Springs State Park for 18 years, points at the pool. "That's Betsy," he says, as he lobs another salad leaf to the mammals. "That's Ariel, and that's Shantay." I wave a hello to the impossibly large, yet demure, beasts. ‌ "It's the best job in the world," Gerry grins. These manatees are here to recover from their wounds – the park rehabilitates around 12 manatees a year, and hundreds come to shelter in the warm waters ever winter. On average, around 100 are killed in boat collisions every year, accounting for 25% of manatee mortalities in Florida; worrying figures for a threatened species. But it's not their biggest threat.

Manatees gather in warm water in winter, as they cannot survive below 20C (68F). Credit: Save the Manatee Club These rotund herbivores can only survive in temperatures above 68F (20C). And, they need to eat 9% of their bodyweight in seagrass – every day. Pollution has decimated seagrass populations, and human development has destroyed their natural habitat – Florida's warm springs. And so they've come to rely on an unlikely source for warmth: coal and gas power plants.

Warmer waters Around 60% of Florida's manatees use the power plants as winter refugees. The only issue now is that there's no seagrass growing in those places anymore. Over the winters of 2021 and 2022, 1,900 manatees died of starvation. And in the long run, these fossil fuel power stations will be replaced by clean power sources that release no warm waste water. ‌ It's a "hypercomplex" situation, Ben Prater, of the Defenders of Wildlife nonprofit, tells me. The power plants will be decommissioned in the coming decades, and so environmentalists are scrambling to find new warm habitats for the animals – from constructing special thermal refuges to deploying solar-powered heaters. ‌ Read my full report on the race to safe Florida's beloved sea cows.

NUMBER OF THE WEEK 20% The decline in production in key hop-growing regions of Europe. Scientists are searching for varieties that can withstand hotter, drier conditions to keep climate change from souring the taste of British beer.

TAKE A MOMENT The tech firms seeking to feed the world with AI As farmers worldwide get older and retire, some hope artificial intelligence could step in to help fill the void. Read more

CLIMATE QUIZ How many seconds does it take for four Olympic-sized swimming pools' worth of water to travel through the turbines of Brazil's Tucuruí hydroelectric dam? A. 1 second B. 4 seconds C. 25 seconds Scroll to the bottom of this newsletter for the answer.

THE BIG PICTURE The world's lingering asbestos problem Removing asbestos is a hazardous job, which climate change is making harder. Credit: Getty Images It's in houses, offices, pipes, soil and our water supplies too. Even in countries where its use has long been restricted, asbestos still poses health risk from its centuries of use as a fire-resistant "magic mineral". Climate change is adding to the challenge of the urgent need to clear up asbestos. Extreme weather is putting asbestos-ridden buildings at greater risk of flooding, as it is the landfills where the material is discarded. Is there a better way to clean up this toxic legacy material? Katharine Quarmby reports for BBC Future.

BEFORE YOU GO Glassmaking is a stubborn climate problem, but an electric revolution is on its way, writes Ben Morris. Do you have an e-waste "drawer of doom"? If so, it's time to recycle its contents, campaigners say. Animals are on the move – but climate change is altering how, when and where they migrate, The Climate Question explores.