5 November, 2024

Martha Henriques Today we are travelling deep underground. My colleague Katherine Latham abseiled into the spectacular Wookey Hole caves in Somerset, the UK, to learn about what the deepest places on Earth can reveal about life and the Universe. Las Vegas, the city of excess, is investing millions in sustainability, plus we explore the US island ruled by snakes and spiders.

THE BIG PICTURE Sin City is going green Las Vegas is switching to renewable energy sources to keep its famous lights on. Credit: Getty Images The bright lights of Las Vegas are a symbol of excess and hedonism in modern America. But Sin City is quickly turning into Solar City. Many resorts on the famous Las Vegas strip are capitalising on the 320 days of sunshine the area receives, and the city now has more solar energy capacity per resident than any other place in the continental US. But as the city's population continues to grow, there are still challenges ahead for this energy-intensive playground. Find out more about how Las Vegas has transformed itself into a sustainability leader in this story by Lucy Sherriff.

CLIMATE CONVERSATION  The climate archives deep underground Caves are time capsules of information; of human history and the life that came before us. Credit: Fran Gomez de Villaboa Katherine Latham, Wookey Hole Squeezing through a gap not much wider than myself, my heart begins to thump. Beyond is utter darkness. Following close behind me into Wookey Hole – part of a maze of caverns beneath Somerset, UK – are renowned cave explorer Phil Short, caving guide Becca Burns, and photographer Francisco Gomez de Villaboa. ‌ A few more twists and turns lead us to a cliff edge. I am first to abseil into a large chamber known as the Witch's Kitchen, where I find myself alone with the witch – a person-sized stalagmite rumoured to be the petrified figure of the Witch of Wookey Hole. ‌ You might be wondering, what would possess someone to descend into the shadows of the underworld? Well, caves – it turns out – are both archives of climate history, and indicators of what the future may hold. They are time capsules of information; of human history, the life that came before us, and what that life could look like in a climate change-ravaged future. ‌ "Caves need to be protected," says geomicrobiologist Hazel Barton at the University of Alabama. "They're an incredibly vital resource. We're finding things out about life on Earth that we didn't know, because you can only study them in caves." ‌ Barton's research revealed the microscopic life that dwells deep underground is surprisingly diverse, and many microbes – that have never had any contact with humans or exposure to man-made drugs – are already naturally resistant to antibiotics. ‌ "It's exciting," she says, "because, before we see that in a clinic, we can start developing drugs to inhibit that resistance. There's nowhere on Earth other than a cave that you can do that. Antibiotics are in our atmosphere. They're in our soil, our food, our water. It's really hard to find a site where there are no man-made antibiotics."

The microscopic life that dwells deep underground is surprisingly diverse. Credit: Fran Gomez de Villaboa The secrets of the deepest darkest places on Earth Caves are also hotspots of endemism, Oxford University entomologist Leonidas-Romanos Davranoglou, tells me. In 2023, Davranoglou trekked to the Cyclops Mountains in Indonesia – where he found a "treasure trove" of underground species, all new to science. ‌ "The discovery of each new species can tell you about the evolution of a whole lineage," he says. "It can help you understand how organisms were distributed in the past – which ecological and geological factors drove the speciation of different groups. This is particularly pertinent to the ongoing climate crisis."  ‌ By studying how past climatic events have shaped the current distribution of animals, Davranoglou explains, you can "generate models that can tell you how anthropogenic climate change will affect their distribution in the future" – and how ecosystems and species could adapt in response to such rapid environmental changes. ‌  You can read the full story here.