Hazy skies the backdrop for Obama's climate talks in India

New Delhi:  When President Barack Obama arrives in New Delhi on Sunday he will join the city's masses in breathing some of the world's filthiest air.

Hazy skies will serve as the backdrop to meetings with Indian Prime Minister Narendra Modi and other officials who are expected to discuss grave environmental concerns: heavy reliance on fossil fuels that has transformed New Delhi into the planet's most polluted capital and made India the third biggest national emitter of greenhouse gases.

With 1.26 billion people and counting, India's energy choices can make or break global efforts to prevent climate change. Experts expect the US will be willing to help India finance ambitious plans to boost production of cleaner energy. That would allow Asia's third-largest economy to reduce reliance on coal and oil but not derail the energy-intensive growth need to reduce staggering poverty.

"You cannot expect India to punch far above its weight. But you also can't have India doing everything in a climate-unfriendly way," said Samir Saran, a climate policy analyst with the Delhi-based think tank Observer Research Foundation. "We have to make a special plan for India."

As hopes rise for a new global climate pact in Paris later this year, some think President Obama can broker with India another landmark deal like last year's U.S.-China climate agreement in which China pledged to rein in emissions starting in 2030.

India applauded that deal for acknowledging that developing countries have a right to keep growing, and polluting for a time, while the U.S., which industrialized long ago, begins curbing emissions now.

Delhi has long refused to curb carbon emissions while hundreds of millions of Indians live in dire poverty. Instead, India has pledged to reduce its emissions intensity - how much carbon dioxide it puts out per dollar of economic activity.

It's also pledged an enormous increase in installed renewable energy capacity by 2022 with a five-fold increase in solar capacity and a massive overhaul of India's dilapidated energy grid. The plan is estimated to require $162 billion in investment, and India will be looking for the US government and businesses to help.

Some hope President Obama will also urge India to move more aggressively in fighting air pollution, after he last year ordered more stringent fuel standards for trucks while also setting unprecedented greenhouse gas limits on power plants.