Summary/Abstract
From mid-June until the end of August 2022, large parts of Pakistan experienced record-breaking monsoonal rainfall, leading to large parts of the country being flooded.
Pakistan is reported to have received more than 3 times its usual rainfall in August, making it the wettest August since 1961. The two southern provinces, Sindh and Balochistan, each experienced their wettest August ever recorded, receiving 7 and 8 times their usual monthly totals. The Indus river, that runs the length of the country, burst its banks across thousands of square kilometres, while the intense rainfall also led to urban flash floods, landslides.
The rains and resulting flooding affected over 33 million people, destroyed 1.7 million homes, and nearly 1500 people lost their lives (NDMA, 2022; VOA News, 2022). On August 25th, the government declared a national emergency. Damages likely exceed preliminary estimates of around US$30 billion with further economic disruption certain in the months to come (Business Standard, 2022), as around 6700 kilometres of road, 269 bridges and 1460 health facilities were destroyed (OCHA, 2022), 18590 schools damaged (Save the Children, 2022), approximately 750 thousand livestock were killed (NDMA, 2022) and around 18,000 square kilometres of cropland were ruined, including roughly 45% of the cotton crop – one of the nation’s key exports. The loss of food crops totalling around US$2.3 bn also compounds the ongoing food shortages due to the war in Ukraine and summer heatwaves in the region. There is also a severely heightened risk of the spread of disease, as stagnant flood waters provide a breeding ground for pathogens, and the vast number of people displaced results in poor hygiene and sanitation in temporary accommodation (Sarkar, 2022; Baqir et al., 2012). Notably, across Sindh and Balochistan, there has been an outbreak in waterborne disease such as diarrhoea and cholera, as well as skin and eye infections, and malaria (IRC, 2022).
To analyse whether and to what extent human-caused climate change altered the likelihood and intensity of this extreme rainfall, scientists from Pakistan, India, the Netherlands, France, Denmark, South Africa, New Zealand, the US and the UK used published, peer-reviewed methods to perform an event attribution study, focusing on two aspects of the event: (1) The annual maximum of the mean 60-day precipitation during June-September over the Indus river basin, and (2) the annual maximum of the mean 5-day precipitation in June-September over the worst hit provinces Sindh and Balochistan.