MUMBAI — Under a fingernail moon at Sassoon Docks, Parumati Mangela, a fisherwoman, sat on her haunches, grimacing. Something strange is happening over the Arabian Sea, she said: “The sky is getting hot more and more,” perhaps because something has angered the goddess Lakshmi.

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.