Climate change-fueled flooding in China is threatening cities, manufacturing, and food security
We’re bringing you exclusive content from our newsletter, The Forecast, right here on Medium. Sign up here. This story is from our feature called the Weather Corner, where we take a deep dive into weird weather around the world, from our August 10th, 2021, newsletter.
In China late last month, a 3-day-long deluge of rain brought the equivalent of an average year’s worth of water to the northern megacity Zhengzhou. In that time, the city saw a total of 24 inches, compared to an annual average of 24.5 inches.
Resulting flooding displaced one million people, caused 11 billion yuan (US$1.7 billion) in property damage, and reportedly killed dozens of people across the region — trapping some in subways, cars, in basements, or sweeping them under swirling waters and mudslides.
Much like certain parts of Germany, the Netherlands and Belgium, the region saw unusually slow-moving rain storms cause massive flooding. These events make it painfully clear how climate change can exacerbate seasonal rains.
China, especially the Henan region that Zhengzhou is located in, routinely experiences flooding in the summer months. The season typically has typhoons off the coast and heavy rains inland. Henan in particular is part of the Yellow River basin, so the province has several major river systems running through it that are prone to flooding amid summer storms. In fact, one nickname for the Yellow River is “China’s Sorrow” because the river has historically overflowed its bank and caused devastating floods that killed millions of people.
In the past century, however, China disrupted these river systems to build up dams, levees, and reservoirs — cutting connections between rivers and lakes and building over flood plains that once absorbed annual summer downpours. The water helped as Henan rapidly urbanized and converted much of its open lands and forests into farmland in the later half of the 1900s. Now, the region is a major base for industry and agriculture.
But climate change threatens this precarious situation. Greenhouse gases trap heat in the Earth’s atmosphere, causing average temperatures to rise all over the world. Warmer air can hold more moisture, which can supercharge storms. Worse storms, obviously, lead to worse flooding (although flooding itself is a complex phenomenon that occurs due to many causes, including land development and ground conditions).
Zhengzhou experienced a perfect storm of such unfavorable conditions. In the city, tunnels and subways flooded, power to at least one hospital was cut, and roads collapsed. Across the province, several dams and reservoirs breached warning levels, and soldiers were mobilized to divert rivers that had burst their banks. Flights and trains in many parts of Henan were suspended. Authorities said 200,000 people were displaced by the floods and more than three million people were affected.
In addition, as a result, supply chain disruptions abounded. One complex in Zhengzhou that produces almost half of Apple’s iPhones sold worldwide was affected by the flooding and had to trigger its emergency response, according to the Wall Street Journal. Apple is gearing up to launch this year’s new iPhones, and so assembly and shipping could be potentially delayed, although Apple has said that it won’t be as of now. Overall, the storms caused $10 billion (65.5 billion yuan) in economic losses in the manufacturing sector, according to China Daily.
More agrarian parts of the province that have hog farms and wheat growing experienced this heavy rainfall, as well, leading to in-field flooding and logistical transportation problems. More than 200,000 hectares of farmland were underwater, according to Reuters. In addition, small farmers expected to be severely affected by the torrential rains with a “significant” short-term impact on logistics, including the transportation of hogs, according to Shanghai JC Intelligence, an agriculture consulting firm.
Another concern is the potential outbreak of African swine fever, Lin Guofa, a senior analyst at consultancy Bric Agriculture Group, told Bloomberg. Floods can increase the risk of disease because healthy hogs may be infected through contact with sick pigs or contaminated feed and water.
China experienced a major outbreak of African swine fever starting in 2018. By 2019, the country had lost 100 million hogs, according to CNN. While it has mostly recovered, the situation remains complicated. The country is a top pork consumer and exporter. This year, China has reported 11 incidents of the disease, but new strains with milder symptoms and a longer incubation period are emerging. This makes it difficult to identify cases immediately, the farm ministry said.
The Henan province is the second-largest hog producer. It’s home to the world’s biggest pig farm operated by Muyuan Foods Co. and the planet’s top pork processor, WH Group. Muyuan’s shares fell almost 5% that week to the lowest since November last year.
Beyond pig farming, the Henan province is China’s top wheat grower, accounting for nearly 30% of output. While the main wheat crop has already been harvested, rains have likely affected its quality, which will lead to greater levels of imports.
According to the South China Morning Post, altogether, the floods resulted in direct economic losses of 2.25 billion yuan (US$348 million) for China’s poultry and livestock industries after 248,000 pigs and 6.4 million chickens died.