Study finds five-day & 60-day maximum rainfall events this season were once in a 100 years events
The catastrophic floods in Pakistan this monsoon, especially in August, were impacted by global warming, according to a new study by the World Weather Attribution (WWA).
The WWA is a group of scientists from around the world studying extreme weather events to discover how much human-induced global warming and climate change are responsible for them.
The floods directly resulted from extreme monsoon rainfall throughout the season, which intensified during August. A continuing La Niña in its third year, along with global warming-induced heat waves from March till May, have been cited as reasons for the extreme rains.
Read more: Pakistan floods: What role did climate change play?
Global warming would have increased glacial melt throughout the mountainous areas of Pakistan, the study said.
WHO Director-General Tedros Adhanom Ghebreyesus said:
There is potential for a second disaster in Pakistan: A wave of disease and death following this catastrophe, linked to climate change that has severely impacted vital health systems leaving millions vulnerable.
The director-general appealed to donors in a statement September 17, 2022 for more funds to reduce the impact of this impending crisis.
The WWA study on Pakistan floods analysed two types of maximum rainfall events — over five-day periods and 60-day periods. Both the five-day and 60-day maximum rainfall events this season were once in a 100 years events, as per the study.
For five-day maximum rainfall events, intense rainfall has become heavier as the country has warmed, showed the analysis.
“Some of these models suggest climate change could have increased the rainfall intensity up to 50 per cent for the five-day event definition”, said the study.
In Sindh and Balochistan — provinces that the floods affected the most — the five-day rainfall extremes were 75 per cent more intense than a world without global warming.
On the other hand, 60-day extreme rains were 50 per cent more intense, according to the study. Both these provinces recorded their wettest August this year, with seven and eight times their normal rainfall for the month, respectively. Pakistan received three times its normal rainfall in August, which was the highest since 1961.
The researchers also cautioned that these estimates carry a lot of uncertainty because of the region’s high variability of monsoon rainfall. “Observed changes can have a variety of drivers, including, but not limited to climate change,” said the study.
Another source of uncertainty is the fact that the region constitutes the western end of the south Asian monsoon region. There is a great difference in rainfall between dry western parts and wet eastern parts.
“Many of the available state-of-the-art climate models struggle to simulate these rainfall characteristics,” the researchers said. The models that are good enough do not match with the actual observations made. This makes it difficult to quantify the exact role of climate change in the flooding event.
Read more: Flood-protection measures: Pakistan is in for a long haul
The floods that actually began in June and continued till August Killed over 1,500 people, affected 33 million and caused economic losses of over $30 billion. This devastation had come at a time when the country was also undergoing severe economic stress.
Agricultural losses worth $2.3 billion across 18,000 square kilometres of cropland, including 45 per cent of the cotton crop, took place, said the study.
Cotton is the country’s main export. It would take a long time for Pakistan farmers to recover from this debacle.
Pakistan has been asking for loss and damage payments under the United Nations Framework Convention of Climate Change’s (UNFCCC) Paris Agreement of 2015. It has asked historical greenhouse gas emitters like the United States and Europe to pay for the loss and damage since the floods happened.
Pakistan has emitted only 0.3 per cent of global GHG emissions since 1751, while the US has emitted a quarter of all GHG emissions. The current study significantly strengthens Pakistan’s claim for the payments to be made.
Loss and damage payments are going to be an essential component of the negotiations at the UNFCCC’s Conference of Parties 27 to be held at Sharm El-Sheikh in Egypt in November 2022.
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