NEW DELHI — Within seconds, the scenic mountain valley resembled a war zone.
“Guys, we have to run!” said a man filming the devastation unfolding in his hillside town in northern India on Sunday, as a landslide set off by incessant monsoon rains sent heavy rocks tumbling down a steep slope.
At least nine people were killed when a boulder struck their vehicle. Their deaths added to a toll of at least 164, with 100 reported missing, on the country’s western coast, where heavy rains have deluged entire towns and villages.
India’s monsoons have always arrived with fury. But the scenes of death and destruction playing out in the country are yet another reminder of the urgency of climate change, experts say. A warming climate means extreme rainfall in many parts of the world, scientists have said.
Record rainfalls in central China and Western Europe have killed scores in recent weeks and displaced many others. On Saturday, the authorities in the Philippines evacuated thousands of residents after a tropical storm flooded the capital, Manila, and nearby provinces.
“The threat of rising sea level is something that we often overlook and underestimate,” said Roxy Koll, a climate scientist in India and one of the authors of a study released last week on how a warming climate will make heat waves and cyclones more frequent and more ferocious in India.
“Climate change is a threat multiplier,” the authors, Mr. Koll and Chirag Dhara, an assistant professor at Krea University in the southeastern state of Andhra Pradesh, wrote in the study. “In the absence of rapid, informed and far-reaching mitigation and adaptation measures, the effects of climate change are likely to pose profound challenges to sustaining the country’s rapid economic growth.”
India’s agrarian economy depends heavily on monsoon rain. Too little means a drought, and too much can cause catastrophic flooding. Extreme rainfall washes away fertile topsoil, while droughts deplete groundwater reserves that have been declining rapidly in many parts of the country for years. Together, they have caused misery and death on India’s farms.
Over the weekend, heavy rains continued to pummel the western state of Maharashtra, where rescue workers struggled to reach areas cut off by flooding and landslides. Workers dug through mud and transported people by boat in areas where the water had reached the tops of houses.
Nearly 300,000 people have been evacuated and thousands were staying in relief camps, state officials said on Monday. There have been more than 250 deaths in the state related to the monsoon season since it began last month.
Uddhav Thackeray, Maharashtra’s top official, said on Twitter that his helicopter could not land because of “low visibility” as he tried to visit flood-affected areas in the district of Satara.
India’s meteorological department forecast “fairly widespread to widespread rainfall” for the next two days across northern, eastern and western parts of the country.
About 1,000 miles from Maharashtra, in the northern state of Himachal Pradesh, officials said on Monday that at least 100 people remained stranded after the landslide on the mountain slope, and that rescue efforts were continuing.
Video footage showed heavy rocks knocking down a metal bridge. The boulders pounded vehicles and fell into a nearby river, making giant splashes and sounds akin to exploding bombs.
“The accident caused by landslide in Kinnaur, Himachal Pradesh, is very sad,” Prime Minister Narendra Modi said on Twitter. “My heartfelt condolences to the families of those who lost their lives.”
Mr. Modi announced compensation of 200,000 rupees, or more than $2,500, to the families of those who died.