Torrential downpours intensified by climate change led to the deaths of over 1,600 individuals and the displacement of millions following deadly cyclones that ravaged Malaysia, Sri Lanka, and Thailand in late November, as per a recent report from the World Weather Attribution (WWA) group. Climate researcher Sarah Kew from the Royal Netherlands Meteorological Institute, who spearheaded the study, highlighted the abnormal surge in storm intensity and its devastating impact on lives.
A team of 21 research scientists delved into the causes of the fatal storms. For instance, in the case of Cyclone Senyar in the Malacca Strait, they found that sea temperatures had risen by 0.2°C in the northern Indian Ocean, fueling the storms with additional heat and moisture. The report indicated that without the influence of fossil fuel warming, these temperatures would have been approximately 1°C lower than the 30-year average.
Although the research could not precisely quantify the role of climate change due to limitations in climate models, it underscored the dangerous combination of heavy rainfall, exacerbated by warming trends and the repercussions of other detrimental environmental alterations. The storms in late November triggered catastrophic landslides, floods that submerged residences and medical facilities, and even wiped out entire villages.
In Sri Lanka, residents in Mwathura have been engaged in rescue efforts and cleanup operations since the cyclone hit. Nisankka Kumarage, a local, recounted receiving a cyclone warning the night the disaster struck, noting a loud noise at 2 a.m. that did not seem unusual initially. However, Kumarage later discovered that a significant portion of the village had been engulfed by a landslide, burying numerous individuals.
The analysis by WWA indicated that, with the influence of climate warming, the likelihood of such an intense storm occurring is now once every 30 years. However, it was the heavy rainfall, rather than the wind, that caused the majority of the devastation.
Despite early warnings issued in Sri Lanka and Indonesia, many residents underestimated the magnitude of the ensuing storms. The lack of experience with tropical cyclones in equatorial regions intensified the impact on local communities, as highlighted by Clare Nullis from the World Meteorological Organization. In Gampaha, Sri Lanka, Malika Kumari described the incessant rain over three days, which led to unexpected and severe flooding that submerged everything in water.
The formation of the cyclone, with its slow movement over the North Indian Ocean, carried substantial moisture, contributing to the unprecedented torrential rain, as explained by Lalith Rajapakse, an engineering professor involved in the WWA study. The flooding surpassed historical levels, with waters rising up to four meters in some regions, rendering even second-floor refuge ineffective.
The WWA findings projected that heavy precipitation events over five days would be significantly more intense, ranging from 28 to 160 percent compared to recent decades. The deforestation of hillsides and the urbanization of floodplains in Sri Lanka exacerbated the impact, leading to severe damage to infrastructure, buildings, and water supplies.
Preliminary assessments by WWA indicated economic losses in Sri Lanka amounting to three to five percent of the national GDP, equating to $6 billion to $7 billion US, while Indonesian recovery costs were estimated to exceed $3 billion US. The devastation underscored the urgent need for preparations to mitigate the impact of future climate-induced extremes in the region.
