People are rescued after flooding in Canoas, at the Rio Grande do Sul state, Brazil. Reuters

Authorities in southern Brazil scrambled Sunday to rescue people from raging floods and mudslides in what has become the region’s largest ever climate catastrophe, with at least 78 dead and 115,000 forced from their homes.

Entire cities were underwater, with thousands of people cut off from the world by the floodwater, brought by days of torrential rains. In Porto Alegre, the capital of Rio Grande do Sul state, residents stood on rooftops hoping to be rescued as others in canoes or small boats navigated streets that have become rivers.

After what one climatologist called “a disastrous cocktail” of climate change and the El Nino effect, more than 3,000 soldiers, firefighters and other rescuers were trying to reach residents, who were in many cases trapped without basic supplies such as running water or electricity. Civil defence officials said at least 105 people were missing in the latest of a string of catastrophic weather events to hit the South American giant.

“It looks like a scene out of a war, and after it is over it will require a post-war approach,” Rio Grande do Sul governor Eduardo Leite said, flanked by President Luiz Inacio Lula da Silva and several government ministers. Lula promised the government would provide all necessary resources for reconstruction. Besides Porto Alegre, another 341 towns and villages have been hit by the flooding. Soldiers are setting up field hospitals after hundreds of patients had to be evacuated from regular hospitals, while civilians have also formed volunteer groups to gather basic supplies, including life jackets, water and fuel. “Everyone helps in their own way, as they can,” said Luis Eduardo da Silva, a 32-year-old volunteer.

The Guaiba River, which flows through the city of 1.4 million people, reached a record high level of 5.3 meters (17.4 feet), according to the local municipality, well above the historic peak of 4.76 meters that had stood as a record since devastating 1941 floods.

“Rio Grande do Sul has always been a meeting point between tropical and polar air masses,” climatologist Francisco Eliseu Aquino told AFP. “But these interactions intensified with climate change” to create “a disastrous cocktail that makes the atmosphere more unstable and encourages storms.” Rosana Custodio, a 37-year-old nurse, fled her flooded Porto Alegre home with her husband and three children. “During the night on Thursday the waters began to rise very quickly,” she told AFP via a WhatsApp message. “In a hurry, we went out to look for a safer place. But we couldn’t walk... My husband put our two little ones in a kayak and rowed with bamboo. My son and I swam to the end of the street,” she said. Her family was safe, but “we’ve lost everything we had.”

Authorities scrambled to evacuate swamped neighbourhoods as rescue workers used four-wheel-drive vehicles -- and even jet skis — to manoeuvre through waist-deep water in search of the stranded. Governor Leite said his state, normally one of Brazil’s most prosperous, would need heavy investment to rebuild.

Long lines formed as people tried to board buses, although bus services to and from the city center were cancelled. The Porto Alegre international airport suspended all flights on Friday for an undetermined period, with its runways underwater.

Lula posted a video of a helicopter depositing a soldier atop a house, who then used a brick to pound a hole in the roof and rescue a baby wrapped in a blanket. The speed of the rising waters unnerved many. “It’s terrifying because we saw the water rise in an absurd way, it rose at a very high speed,” said Greta Bittencourt, a 32-year-old professional poker player.

Leite said this was the worst natural disaster in the history of Rio Grande do Sul, which is home to agroindustrial production of soy, rice, wheat and corn. Lula, who visited the state twice in a matter of days, has blamed the disaster on climate change.

South America’s largest country has recently experienced a string of extreme weather events, including a cyclone in September that killed at least 31 people.

Brazilian crop woes

Soybeans slid on Monday as the market took a breather after climbing to a six-week high earlier in the session, with floods in Brazil’s key growing state threatening to reduce supplies from the world’s top exporter. Wheat prices slid 1.7%, giving up some of the recent gains, which were triggered by dry weather in top exporter Russia, while corn fell for the first time in four sessions. The most-active soybean contract on the Chicago Board of Trade (CBOT) was down 0.6% at $12.08 a bushel, as of 0409 GMT, after climbing to its highest since March 21 at $12.19 a bushel earlier on Monday. Wheat fell 1.8% to $6.11-1/4 a bushel and corn lost nearly 1% to $4.56 a bushel.

The outlook for the soybean harvest in Rio Grande do Sul, which was on track to become the second-largest producer in Brazil behind Mato Grosso state, is deteriorating swiftly after torrential rains flooded fields, with about a quarter of beans to be reaped. The state is also Brazil’s sixth-largest corn producer.

In Argentina, corn stunt disease spread by leaf-cutter insects and adverse weather prompted the Buenos Aires grains exchange to slash its estimate for Argentina’s 2023/24 corn harvest by 3 millions metric tons to 46.5 million tons.

Worries of crop losses in Russia have been driving gains in the wheat market over the past few weeks, with CBOT wheat up 8% in April. “Speculators have held bearish bets in Chicago wheat for nearly two years, but excessively dry weather in top exporter Russia as well as concerns for other global wheat crops have recently ignited notable short covering,” Karen Braun, a market analyst for Reuters, wrote in a column. Russia’s IKAR agricultural consultancy has cut its forecasts for Russia’s wheat crop to 91 million tons from 93 million tons and wheat exports to 50.5 million tons from 52 million tons, it said on Friday.

Large speculators trimmed their net short position in Chicago Board of Trade corn futures in the week ended April 30, regulatory data released on Friday showed.

The Commodity Futures Trading Commission’s weekly commitments of traders report also showed that non-commercial traders, a category that includes hedge funds, trimmed their net short position in CBOT wheat and trimmed their net short position in soybeans.

Agencies