As Ms. Mangela rounded up village women to pray at the water’s edge, state fisheries scientists were tracking worrying changes in the water, where in the last half century average surface temperatures have risen three-tenths of a degree Celsius, or half a degree Fahrenheit. This warming is driving familiar species into cooler waters, they say, replaced by species traditionally found hundreds of miles to the south, like Indian mackerel and oil sardines.

At the climate talks in Paris, India’s negotiators have staked out an adamant position: While India is vulnerable to global warming, raising a vast population out of poverty remains the national priority. The government plans to double use of domestic coal to more than a billion tons by 2019, and maintains that the legal obligation for action on climate change should fall on developed countries, which burned huge amounts of fossil fuels for decades.

But few countries have so much at stake as India. For the last month, the front pages of major newspapers have been dominated by one environmental crisis after another: City-dwellers are up in arms about hazardous levels of air pollution, which has already damaged the lungs of about half of Delhi’s schoolchildren. And last month brought torrential rains and flooding in the southern city of Chennai, evoking the erratic weather that climate experts warn about.

“People are experiencing far more, and the impacts are far more severe,” said Arivudai Nambi Appadurai, a climate risk specialist for the World Resources Institute, whose family weathered the flood in Chennai. “It is right there in front of them. You experience it, you believe it. It’s not something happening far away that you read about in the newspaper.”

Ashok Lavasa, secretary of India’s Ministry of Environment, Forest and Climate Change, said negotiators were aware of the impact climate change is having on the country, which has more than 4,000 miles of coastline and 1,200 islands. But India takes the view that developed countries, like the United States, are responsible for the problem, and must take the biggest steps on a solution, a notion enshrined in the 1997 Kyoto Protocol. Mr. Lavasa would like to see that legal divide continue, even though developing economies are expected to become the largest greenhouse gas emitters in the 21st century.

“When you talk about historic obligations, we are not reinterpreting those agreements,” Mr. Lavasa said.

Four thousand miles from the Paris talks, a familiar smog has settled over India’s large cities, reducing the midday sun to a pale, blurry wafer. The pollution, a dangerous mix of suspended particles from kerosene stoves, vehicles, diesel generators and burning crops, trash and firewood, is at the same high level as November of last year. But awareness has soared, said Joshua S. Apte, an assistant professor of environmental engineering at the University of Texas at Austin, who has studied Delhi’s air pollution since 2007.

Take the case of Manisha Pathak, 44. Ms. Pathak, who has lived in Delhi for two decades, left home with her children Sunday night, on a short walk to get ice cream. Her father now informs her every morning of the neighborhood’s concentrations of PM 2.5, particulate matter that is considered the most dangerous because it penetrates deep into the lungs, contributing to heart attacks and strokes.

Average concentrations near her house last month were 331 micrograms per cubic meter; 10 is the level considered safe by the World Health Organization. Ms. Pathak’s father has abandoned his morning walk; her brother-in-law, who has asthma, is exploring a transfer out of New Delhi. And on Sunday, Ms. Pathak was seized with anxiety over whether it was safe to be outside. She told her children to walk faster.

“It was horrible the moment we got onto the main road,” she said. “You can feel that whatever you are inhaling, it is not air. It is something you should not inhale.”

Similar fears are radiating through middle- and working-class neighborhoods of Delhi and Mumbai. Dr. Vivek Goswami, a consulting pediatrician at Fortis Hospital in Delhi, said asthma diagnoses in children had jumped by 20 percent over the same period last year.

Ms. Pathak said she now believed limiting emissions should be a priority for the government. “It is needed and required,” she said firmly. “This is a basic thing that a man needs.”

Though global warming and air pollution have distinct causes, the issues overlap in the minds of many young urban Indians — a group far more likely to support limiting greenhouse gases, the Pew Research Center found in a survey conducted ahead of the climate talks. The survey also found that 76 percent of Indians consider climate change “a very serious problem,” compared with 45 percent of Americans and 18 percent of Chinese.

Some climate experts are reminded of the pollution protests that broke out in Chinese cities last year, prompting the Chinese premier to declare a “war on pollution.”

“The media, in a way that couldn’t happen in Beijing, has made this such an issue that policy makers can’t be seen to be avoiding it,” Mr. Apte said.

For farmers and fishermen, the changes associated with a warming climate have emerged gradually.

Vinay D. Deshmukh, a fisheries scientist who headed a marine research center in Mumbai, recalled his puzzlement around seven years ago, when he first saw boats coming back loaded with oil sardines, a fish whose northernmost range traditionally ended 400 miles to the south. The fish, he said, were “emaciated,” with bulbous heads and little flesh. His hypothesis: The sardines, “running away from the hot water to survive,” had wandered so far that they no longer had a familiar stock of phytoplankton.

Since then, the oil sardines have expanded their range 900 miles, turning up in the nets of fishermen as far north as Bangladesh. Mumbaikars showed so little interest in eating sardines that they are now ground up as a supplement for animal feed.

Chabi Gayakard, scanning the crowd for paying customers at Sassoon Docks, shook her head disapprovingly when asked about the sardines. “The hotter it gets, the more they come,” she said. “Upper-class people don’t eat them.”

A friend, standing over a dead shark, suggested that God had sent waves of heat as a punishment, after “watching how we humans behave.”

A thousand miles north of Mumbai, the apple farmers of Himachal Pradesh, in the foothills of the Himalayas, are following the Paris talks raptly.

As children, they waded through heavy snowfall in their orchards by mid-December, but now the cold temperatures necessary for apple farming come a month and a half later, and some farmers have moved orchards as much as 2,000 feet higher, where the temperature is cooler.

Over the last seven years, virtually all the apple farmers have come to believe that global warming is a major factor in the decline of crops, said Ravinder Chauhan, president of the Apple Growers Association of India.

“My worst anxiety is that the process of global warming may be irreversible,” he said. Every day, since the beginning of the Paris talks, Mr. Chauhan has scanned the newspapers for reports of progress. At other times, he scans the sky for signs of the snow that once fell in December.

“At the moment, we don’t see anything,” he said. “We are waiting.