NAGAPATTINAM, India, Sept 20 (Thomson Reuters Foundation) - Vinod Kumar remembers a time, not so long ago, when the fields in his village in the southern state of Tamil Nadu were green all year round.
His family lived comfortably from its farmland of just over 2 acres (0.8 hectares), growing vegetables, coconuts and millet irrigated by the Cauvery river and the rain.
Kumar grew up believing the farm would be his life.
But today, the 30-year-old drives a car for a living in the city of Chennai, 250 km (155 miles) away. His family joined him two years ago, abandoning what had been for generations their home and their land.
On a recent journey back to the area where he grew up, he said he was far from the only migrant.
"At this time of year, these fields should be green with paddy shoots - but no one seems to be farming," said Kumar, as he drove past arid fields overgrown with scrub and thorns one sweltering July afternoon.
"We haven't had enough water for many years. It has become impossible to make a living from farming, and a lot of people have moved to cities to do other jobs."
Tamil Nadu endured its worst drought in more than a century after the monsoon rains failed last year - and the combination of lack of water and worsening heat is driving a gathering wave of migration.
In Nagapattinam, in the Cauvery river delta region of southeast India, drought and irregular rainfall have blighted lives for about a decade now.
As ponds and tanks dry up, causing crops to fail and cattle to languish, more people - like Kumar - are moving to cities.
TOO HOT TO SURVIVE?
The Asia-Pacific region, the most prone to natural disasters in the world and home to a fifth of the global population, is struggling with more frequent and intense disasters, from cyclones and droughts to floods and heatwaves.
By the turn of the century, much of South Asia could be too hot for people to survive, according to researchers at the Massachusetts Institute of Technology.
Last year was India's warmest on record - and that increasing heat is contributing to worsening drought, water shortages and migration.
Millions are thought to have fled the severe drought of 2015-16, which the government said affected about 330 million people, or nearly a quarter of the population.
"Two-thirds of the country is in arid and semi-arid regions, so they are already susceptible to higher temperatures and less rainfall," said Suruchi Bhadwal, an associate director at research organisation The Energy and Resources Institute, based in New Delhi.
"Farming is climate-sensitive, and drought is a slow, insinuating event. A farmer will have lost everything by the time it is declared, and he is then forced to migrate," Bhadwal said.
In coastal Nagapattinam, temperatures in May, the hottest and driest month, can go above 40 degrees Celsius (104 degrees Fahrenheit) - a level at which crop yields decline under the stress of extreme heat.
In the Cauvery basin, where Nagapattinam is located, the maximum temperature is forecast to rise by 3.7 degrees Celsius by 2080, while the minimum temperature is seen rising 4.2 degrees Celsius, according to research by the Tamil Nadu Agricultural University.
That increase will cause grain yields to fall up to 40 percent, scientists say.
"We used to easily be able to harvest three crops a year. Now we can barely harvest a single crop," said C. Subramaniam, a farmers' leader in Vettaikaraniruppu village.
"Forget water for farming. We don't even have water for drinking," he said.
The amount of farmland available also is shrinking as salty sea water - which kills most plants - has surged inland, tainting the soil.
Nagapattinam was the Indian district hardest hit by the 2004 Indian Ocean tsunami. Today, where green paddies once stood, there are water-logged shrimp farms stretching to the horizon.
Erosion is also a problem, with the Cauvery delta having shrunk by a fifth over the past four decades, according to research by the Madras Institute of Development Studies.
Such losses are a major problem for a region known as India's "rice bowl".
Tamil Nadu's problems with drought and water shortages are complicated by the already thin margin of survival for many farmers. Most work plots smaller than 2 hectares (4.9 acres).
A majority also do not own the land they cultivate, instead tilling the land as tenant farmers with no access to government loans or insurance plans that offer some protection.
To complicate matters, Tamil Nadu has been fighting a long-running dispute with neighbouring Karnataka state over sharing the Cauvery river water, which is a lifeline for farmers like Subramaniam.
Increasingly, only those who can afford to dig borehole wells are able to coax a living from the land. But even this is getting harder.
S. Murugan, who owns 20 acres of land in Karuvazhakarai village, installed a well five years ago, paying 150,000 rupees ($2,339) for it to be dug 100-feet (30-metres) deep.
Now, as the water table falls from overuse, he is only able to pump enough water to cultivate half his land. Lush green rice paddies lie on one side of the road, barren fields on the other.
"Today, you have to pay more, go 200-250 feet to hit water. Plus there are barely any men left here to work on the fields," he said.
His own son is studying in Chennai and unlikely to return to the land.
"He does not want to farm, and I am also not keen, even though we have always been a family of farmers," Murugan admits.
Farmers who cannot afford borewells have suffered much worse.
More than 200 farmers in Tamil Nadu died or killed themselves between last December and June this year because of distress related to the drought, according to state data.
Most belonged to Dalit and other lower-caste communities that do not own land, and had been unable to repay loans from private lenders.
Across the country, about 60 percent of India's population still depends on the land for its livelihood - a huge problem as climate change brings more weather extremes that make bringing in a harvest harder.
While agriculture made up more than two-thirds of a farm family's income in the 1980s, today it brings in less than a third, with many families seeking alternate sources of income.
But a lack of education for jobs beyond farming is keeping many people on the land, even as it no longer produces a harvest they can rely on.
"The farmer distress is the result of the long-standing neglect of the rural economy," said R. Murali of the rights group People's Union for Civil Liberties.
"People know nothing but farming, there are no other jobs, and they lack the education and skills for jobs in the city," he said.
Still, tens of millions of people - mostly young men - have moved to cities for work in the last decade, analysts estimate, leaving behind women and children and the elderly to eke out a living from the land.
The migrants themselves often end up in slums and informal settlements, with a quality of life not much superior to that on the farm.
SEWING A FUTURE?
Nagapattinam's young men - and increasingly its women - are migrating in growing numbers to the cities of Coimbatore and Tirupur to work in textile and apparel factories.
Others go to Chennai and Bengaluru as security guards or drivers.
Bala Murugan, 28, moved to the apparel hub of Tirupur to sew T-shirts years ago when his family could no longer earn enough from farming. He sends home about 5,000 rupees ($78) a month, he said.
His family, like hundreds of other low-caste families in the district, does not own any land of its own.
Murugan doesn't think he will ever return for good.
"I do not see a future here. We can no longer depend on the land like we used to," he said on a visit home, to a modest hut by the side of a dry irrigation ditch.
"My parents say this is the only work they know, so they will remain here," he added.
NOT ENOUGH HELP?
India's government operates a federal scheme to provide 100 days of work each year to one member of every rural family, in an effort to boost sagging incomes. But activists say the programme is inadequate to meet a rising need for help.
A state climate action plan, drafted in 2014, also outlines measures to boost sustainability, including the introduction of more drought- and flood-tolerant varieties of paddy rice and water-saving irrigation methods.
But too little has been implemented, in too few places, farmers complain.
Kumar, the farmer-turned-driver, however, has not given up.
He is taking lessons in organic farming, and hopes to one day return to his village and reclaim his family's land.
"It's only now that I realise how lucky we were in the village to have clean air and clean water and all that space," he said wistfully.
($1 = 64.1200 Indian rupees)
This is part of a special series on rising heat, read more stories here.
Reporting by Rina Chandran @rinachandran, Editing by Laurie Goering and Megan Rowling.
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