Climate change made last month’s peak rainfall in Pakistan’s Sindh and Balochistan provinces – which contributed to devastating floods that have affected 33 million people – 75% more intense than might have been expected. out in a world without warming, according to an analysis by World Weather Attribution (WWA), a scientific group that studies the link between extreme weather events and climate change.
In addition to rainfall, a heatwave in India and Pakistan earlier this year, also driven by climate changeThe floods that left a third of Pakistan under water have worsened, the scientists found.
The death toll from floods has reached nearly 1,500 people and material damage to the country can pass 30 billion dollars. More than a million houses damaged and thousands of schools and medical facilities destroyed.
Ayesha Siddiqi, an assistant professor of geography at the University of Cambridge, said: “The amount of rain is amazing and this is an unprecedented disaster. “At the same time, the disaster is the result of vulnerabilities that have built up over the years.”
The built environment and social conditions in Pakistan have exacerbated the impact of monsoons. Cities, towns, infrastructure and farms were built in floodplains. High levels of poverty and recent political instability make the country less prepared for disaster.
WWA, which specializes in real-time analytics, has previously asserted that climate change has played a role in UK heat wave this summer and did not during the 2021 food crisis in Madagascar.
The team conducted two different analyzes of rains in Pakistan as the disaster was still unfolding.
In it, it analyzes up to five-day annual rainfall data during the monsoon season in the worst-affected provinces of Sindh and Balochistan. It found that rain concentrated in the southern provinces was 75% more intense than would be expected if the world hadn’t warmed by around 1.2°C since pre-industrial times. Models show that rainfall intensity over a similar 5-day period will increase significantly in the future if the planet warms 2ºC.
The researchers also looked at the effects of climate change on the entire monsoon season – a 60-day period from June to September – in the much larger area of the Indus River basin. For this second study, they found that climate change is making such rainfall across the region 50 percent more intense, although the large variation in rainfall in this region causes uncertain conclusion. The lack of ability of climate models to capture some features of regional weather makes it difficult to estimate the likelihood of increase.
“Monsoons are notoriously difficult to predict,” said Fahad Saeed, a researcher at the Center for Climate Change and Sustainable Development in Islamabad. “Most of the models developed in the Global North and some of the processes that are important to this South Asia region are not integrated in those specific models – so there will be a gap.”
In May, WWA determined that high temperatures in Pakistan and India had been observed 30 times more likely by greenhouse gas pollution. Such heat studies have become relatively simple for scientists, because they are largely based on basic information about global warming: The atmosphere has more heat, hence the heat. increase more frequently and at a higher rate. Floods and droughts also include hydrological factors, adding complexity to the task.
“The role of climate change in heat waves is much larger than in extreme rainfall events like this,” said Friederike Otto, a senior lecturer in climate science at Imperial College London. “Of course some years are very wet and some years drier – we don’t have a lot of data to really determine the return time of such an event.”
During recent floods, the heaviest amounts of water have arrived in the south and west of the country, an arid region where the behavior of the monsoon varies greatly from year to year, leaving patterns Limited data for researchers. Precipitation in the area is particularly sensitive to the presence of La Niña – a cooling of the Pacific Ocean like this year – and also hot spring weather. Pakistan is home to 7,000 glaciers that also melt more than usual in the summer heat, although they can cause far less flooding than rain.
Even if they can’t say how likely it is, the team of scientists believe that a similar event is increasingly likely in a warmer world, says Otto.
Pakistani officials warned of more flooding in some areas over the weekend and the government is trying to deal with a food crisis after floodwaters swept away crops and washed away livestock.
“No country deserves this fate, but especially countries like Pakistan that do almost nothing to contribute to global warming,” said United Nations Secretary-General António Guterres. September 9, calling on the international community to provide the country with “major financial support. ”
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