Climate change made the unprecedented monsoon rainfall that flooded a third of Pakistan last month much more likely, according to a team of scientists analyzing the event.
The dramatic floods killed nearly 1,500 people, caused an estimated $30 billion in damage, and left hundreds of thousands homeless. In August, Sindh and Balochistan provinces both had their highest rainfall totals on record for the month — about seven and eight times their typical monthly precipitation totals.
The new analysis found that such strong rainfall can be expected now once every 100 years in the current climate and even more often in the future as the world continues to warm, researchers said at a news conference held Thursday by the World Weather Attribution initiative. .
The initiative brings together scientists from around the world to analyze newsworthy weather events as quickly as possible and help people understand the role of climate change when it is most relevant. The analysis, which has not undergone an external scientific review or publication in a scientific journal, is based on a methodology that has been peer-reviewed and applied to many recent high-profile weather events. Such analyzes are often published in journals months later.
To understand the fingerprint of climate change on the event, the researchers analyzed the annual maximum for rainfall in the monsoon season for 60 days in the Indus River basin, where the flooding was concentrated. They also looked at the heaviest five-day period of monsoon rains in hard-hit Sindh and Balochistan.
The study found that climate change had increased the likelihood of heavy rainfall for both geographic areas and time periods. As much as a third of the rainfall that fell during the most intense period in Sindh and Balochistan could be attributed to climate change, it found.
The intense monsoon rains “would have been a disastrous amount of rain without climate change, but it’s worse because of climate change,” said Friederike Otto, senior lecturer in climate science at the Grantham Institute for Climate Change and the Environment and a co-founder of the initiative. “Especially in these very vulnerable regions, small changes are of great importance.”
The floods in Pakistan bring more uncertainty than some other recent attribution studies because monsoon rainfall is extremely variable, available climate records only go back as far as the 1950s, and climate models struggle to recreate some of the complex weather processes in the South Asian region. to give .
“It is well known that climate models in this part of the world generally struggle to capture monsoon characteristics,” said Mariam Zachariah, a research associate at the Grantham Institute, which is part of Imperial College London. “We saw that there is a great deal of uncertainty about the results of the models.”
Climate change is not the only factor that has led to such a major disaster, the analysis said. Pakistan had catastrophic floods in 2010, which had similar climate and weather characteristics.
Research into the 2010 floods suggests that water management failures – including dam breaches and irrigation system failures – played a critical role. Development in floodplains and socioeconomic factors such as poverty have also contributed to making Pakistan more vulnerable to disasters, the analysis suggested.
“This disaster was the result of vulnerability built up over many, many years that shouldn’t be seen ahistorically as the result of a sporadic particular event,” said Ayesha Siddiqi, an assistant professor of geography at the University of Cambridge. .
Pakistan is responsible for less than 0.5% of the world’s historic greenhouse gas emissions, but it is one of the countries most vulnerable to the effects of climate change. Millions of people have been displaced by the floods.
World leaders have described helping the country in terms of justice.
“Pakistan needs massive financial support today to overcome this crisis,” UN Secretary-General António Guterres said last week. “This is not a question of generosity. This is a matter of justice.”
Earlier this year, temperatures in the county soared above 122 degrees Fahrenheit. Researchers conducted an attribution analysis of the heat wave and found that it was 30 times more likely to be the result of climate change, according to Fahad Saeed, an Islamabad-based researcher at the Center for Climate Change and Sustainable Development.
This article was originally published on NBCNews.com