20 August, 2024

Xiaoying You London, UK China is once again being pummelled by record-breaking floods, with 30 rivers exceeding historic levels. Last year, furious waves of floodwater tore through Beijing itself. But even as climate change makes extreme weather events more frequent around the world, new – and sometimes extremely old – ways of managing water are surging to the rescue. In Asia, rice paddies are inspiring flood defences, while in Florida the world's largest environmental restoration project is tackling water shortages. Also this week, saving a charismatic giant clam and how to react to an animal attack.

CLIMATE CONVERSATION  A 5,000-year-old answer to flooding Thammasat University's rooftop farm deploys rice paddy-style terraces (Credit: Panoramic Studio/Landprocess) June was my least favourite month growing up in Shanghai. Early summer was the city's wet season, known locally as the "yellow plum days". It featured weeks of drizzle, afternoon showers and humidity, meaning going out to play with my pals was out of the question. ‌ But the annual natural occurrence, driven by Asia's monsoon, is changing. When I last visited my hometown in June this year, the once-gentle "plum rain" was not there. ‌ Instead, intense, intermittent downpours pounded the city, sometimes for hours. People in my neighbourhood made the holes on manhole covers bigger to stop waterlogging. Because of climate change, the plum rain regions in East Asia are now more prone to extreme weather events, such as torrential rain and drought. ‌ Intensifying monsoon rain means China and its neighbours must update their flood-control measures, especially in populous megacities. And for one Chinese professor, the answer isn't to build bigger pipes or stronger banks, but to take a leaf out of the country's agricultural past.

Rice terraces can collect and hold valuable rainwater (Credit: Getty Images) For more than 5,000 years, Asian farmers have grown the region's staple crop – rice – on hills and mountains via paddy fields called rice terraces. Because these tiers are all built along contour lines, they can collect and hold rainwater, allowing the crop to grow. ‌ Water use was central to the ancient agricultural civilisations of China, Indonesia, Malaysia and India, says Yu Kongjian, a professor of landscape architecture at Peking University in Beijing and the brains behind China's "sponge city" concept. "Therefore, [those societies] learned how to collect and reuse rainwater."

Grey vs Green Yu believes such nature-based, indigenous know-how can help the region tackle downpours better than "grey" infrastructure made with steel and cement. While ancient Chinese farmers created a lifestyle that adapted to the monsoon season, the grey infrastructure was invented to serve Europe's milder climate, he says. ‌ In Yu's hometown of Jinhua, a two-hour journey from Shanghai by bullet train, he has designed a large park with a rice-terrace-like bank. Grasses that can live on land and underwater are planted in the terraces to help slow and retain stormwaters. In 2019, a study found the park design reduced yearly maximum flood levels by up to 63%. ‌ There are other equally fascinating designs across Southeast Asia, a region facing increased monsoon rain, rising sea levels and rapidly sinking cities. ‌ "Flooding used to be part of our agricultural society," says Kotchakorn Voraakhom, a landscape architect based in the low-lying Thai capital of Bangkok. "But when we shifted to being urban people, flooding no longer benefitted us. This is part of the problem." ‌ Voraakhom has drawn inspiration from rice terraces to design a green roof for a Thai university. Tiers of small paddy fields cascade down from the top, which – according to Voraakhom's estimates – can slow down excess rainwater by about 20 times and reduce the building's interior temperature by 2-4C (3.6-5.4F) in summer. ‌ People can also use the building's terrain to grow food and enjoy outdoor green space, says Voraakhom. "If we build a building, why can't the building become a mountain itself?" ‌ Read my full report on rice terraces inspiring modern flood control.

NUMBER OF THE WEEK 1 in 3 One third of Floridians rely on The Everglades for their drinking water. And now, thanks to an ambitious new reservoir which will move clean water south, the aquifers in this important ecosystem are set to be replenished. Lucy Sherriff reports on the world's largest environmental restoration project.

TAKE A MOMENT A noble effort Biologists are racing to save one of the Mediterranean Sea's most charismatic and endangered species: the noble pen shell. Keep reading

CLIMATE QUIZ France is set to remain the world's most popular country for visitors, but over-tourism is causing which destination to discourage tourists this summer? A. The lavender-surrounded village of Valaurie B. The bohemian town of St-Tropez C. The capital of Champagne's wine-growing region, Reims Scroll to the bottom of this newsletter for the answer.

THE BIG PICTURE Why do animals attack humans? Bear-proof rubbish bins can help deter urban bears (Credit: Getty Images) Between 1950 and 2019, there were over 5,000 large carnivore attacks worldwide, with almost a third leading to human fatalities. The reasons for this are numerous: ranging from a desire to protect their young, to resource shortages caused by climate change. Yet as Ally Hirschlag explores, research by the Spanish National Research Council suggests that half of such incidents could be avoided if we changed our own behaviours.

BEFORE YOU GO • Flash floods have hit the US and Canada, while in the Himalayas a burst glacial lake has sent icy waters surging through a mountain village. • In India, rural girls are leading a cycling revolution, Soutik Biswas reports, with increasing numbers taking up state-run schemes to help them get to school. • Ever wondered about the carbon-storing power of sharks? Find out more on this week's The Climate Question podcast with Graihagh Jackson.

AND FINALLY... In an experimental forest in the UK's Midlands, a network of pipes has been plumbed in amidst the trunks and foliage. The pipes release a stream of carbon dioxide, to see how the trees respond to elevated levels of the greenhouse gas. One of their reactions has been heartening: the forest's mature trees produced 10% more wood, locking carbon out of the atmosphere for years to come. The finding by scientists at the University of Birmingham adds to the case for protecting primary forest, with an area the size of a football field still lost globally every six seconds.