Climate change intensified Pakistan rains up to 50%, report indicates

Climate change is estimated to have made the rainfall that caused devastating flooding in Pakistan up to 50 per cent more intense, according to a scientific paper published just days before the issue of environmental reparations is expected to be raised at the UN general assembly.

The conclusions of a rapid study of the disaster in Pakistan by 26 scientists from nine countries, as part of the World Weather Attribution group, said computer models indicated rain over a five-day stretch in southern Pakistan was significantly more intense than it would have been without a rise in global temperatures of at least 1.1C since pre-industrial times.

Most of the models “show an increase in likelihood and intensity that is potentially very large”, the scientists said. “There is an urgent need to reduce vulnerability to extreme weather in Pakistan.”

The heavy rain that caused the flooding affected more than 33mn people, destroyed 1.7mn homes and wrecked crops, the government in Islamabad has estimated. The two southern provinces of Sindh and Balochistan experienced their wettest August on record — deluged by up to eight times what would be usual for the month.

Between mid-June and the end of August, large areas of the country experienced record-breaking monsoon rainfall.

The unusually hot summer also amplified the melting of Pakistan’s 7,000 glaciers that feed the Indus river, though the relative contribution of glacial meltwater to the flooding was unknown, the report said.

The effect of the recurring La Niña weather pattern, which has also been behind flooding in Australia this year, was also difficult to determine.

Pakistan heads the so-called Group of 77, a coalition of developing nations at the UN. When the heads of state gather at the general assembly in New York next week, they are expected to be confronted by the issue of poorer nations bearing the consequences of climate change due to the industrialisation of rich nations.

The contentious question of financial aid for climate-related destruction is expected to see renewed calls for rich countries to address the issue of damages — a matter also expected to be a focal point at the UN COP27 climate summit in Egypt in November.

Ayesha Siddiqi, assistant professor at the department of geography at the University of Cambridge, said the response of the international community to the previous catastrophic 2010 flooding in Pakistan had been markedly different from the “pittance” being offered in aid now. The geopolitics at the time had encouraged foreign aid, to stem the influence of the Taliban.

“This time round, we don’t have the same geopolitical imperative to help Pakistan,” she said.

The WWA researchers noted that the seasonal variability in the region’s weather and other factors made it difficult to quantify with certainty the precise extent to which climate change made the extreme rainfall more likely or more intense.

But Friederike Otto, senior lecturer in climate science at the Grantham Institute in London, said that, while it was hard to put an exact figure on the contribution of climate change, “the fingerprints of global warming are evident”.

“What we saw in Pakistan is exactly what climate projections have been predicting for years,” she said. “It’s also in line with historical records showing that heavy rainfall has dramatically increased in the region since humans started emitting large amounts of greenhouse gases into the atmosphere. And our own analysis also shows clearly that further warming will make these heavy rainfall episodes even more intense.”

The scientists also pointed out that the effects of the flooding were partly a consequence of a lack of preparedness, the proximity of people, infrastructure and farming land to flood plains, outdated river management systems and underlying vulnerabilities such as high levels of poverty.

“Being more resilient to these kind of events is a very high priority in terms of local but also global financing and planning,” Otto said.

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