KOCHI: Contradicting earlier climate models that indicated that land was warming faster than the ocean, and thus bringing more rainfall, a new study published in journal 'Nature Communications' on Tuesday suggests a significant decreasing trend in the Indian monsoon over central India in the past century.
The study suggests that Indian Ocean warming has reduced rainfall in the region by 10-20%.
"In the existing global warming scenario, it was projected that land was warming faster than the ocean which meant that there would be more rainfall in the monsoon period. But it is not so in case of the Indian summer monsoon," said Roxy Mathew Koll, scientist and lead author at the Centre for Climate Change Research, Indian Institute of Tropical Meteorology (IITM).
At a time when a back-to-back drought is looming, the study points out that monsoon drivers - land-sea temperature difference and sea surface temperatures - which bring in rains have not become stronger. The El Nino-La Nina imbalance, it adds, has played a role in the Indian Ocean warming.
Authors of the study used India Meteorological Department data from the 1870s and data from other sources from 1901 to 2012 to run their climate model. "We found that the rainfall is decreasing over central South Asia - from south of Pakistan through central India to Bangladesh," Roxy said. "With this, we have to take a relook at climate models which suggested that land in the region was warming faster than the ocean."
