Top Indian government officials are debating whether to set a goal to zero out its greenhouse gas emissions by mid-century, an ambitious target that would require overhauling its coal-dependent economy.
Officials close to Prime Minister Narendra Modi are working with senior bureaucrats and foreign advisers to consider ways to meet the 2050 deadline, according to people familiar with the matter.
A 2047 target is also being considered, they said, to mark the centenary of India's independence from British rule. The people asked not to be identified because the discussions are private.
India, the world's third-biggest emitter, has come under pressure to make a net-zero pledge ahead of global climate talks in Glasgow, Scotland, this year.
Signatories of the Paris Agreement are expected to boost their commitments to slow global warming, and China – the biggest polluter and a rival of India – won international praise for setting a 2060 net-zero target in September.
The timing and scope of India's announcement could depend on pledges other nations make on April 22, when United States President Joe Biden is set to gather world leaders for an Earth Day summit.
The event is the first such meeting Mr Biden will host as president, and he has asked climate envoy John Kerry to secure fresh commitments from attendees.
The Prime Minister's Office, Ministry of External Affairs and Ministry of Environment, Forest & Climate Change in New Delhi did not immediately respond to requests seeking comment.
"Every single country has to step up ambition," Mr Kerry told the BBC during his visit to Britain earlier this month. He implicitly included India while singling out "the 20 countries that are the equivalent of 81 per cent of global emissions".
Once the US adopts a widely anticipated net-zero goal, nine of the 10 largest economies will have made pledges to neutralise emissions.
If India does so, too, it would mark a significant step toward the Paris Agreement aspiration of keeping average temperatures from rising more than 1.5 deg C above the pre-industrial period.
There are signs that support is growing domestically for India to set a net-zero goal.
Mr Jayant Sinha, a member of parliament with Mr Modi's Bhartiya Janata Party, said on March 12 that he had submitted a private members' Bill in the Parliament that would make a 2050 target legally binding.
"A Net Zero Bharat will not only lead to a more prosperous future for India, but it will also play a big role to save the world," wrote Mr Sinha in an opinion article for The Economic Times.
On March 16, Mr T.S. Singh Deo, a Cabinet minister for the eastern state of Chhattisgarh, said the area's health sector is setting a 2050 net-zero target.
"Climate change is one of the biggest challenges being faced by the world today," he wrote on Twitter. "I am pleased to make our small contribution."
Over the past decades, developing countries have contributed far less greenhouse gases to the atmosphere than nations that industrialised earlier. As of 2018, India ranked sixth among top historical polluters, after the US, China, Russia, Germany, Britain and Japan.
Even the Paris accord acknowledges this reality, noting that nations have "common but differentiated responsibilities". The clause has been used to support arguments that rich countries should cut their emissions faster, allowing poorer countries to use fossil fuels for a bit longer to help them achieve the prosperity which the West has enjoyed for decades.
"For countries such as India, the most important thing is to achieve the greatest development for the fewest additional emissions," said Navroz Dubash, a professor at the Centre for Policy Research and editor of the book "India in a Warming World".
"You don't want to do what China did, which is rapidly increase emissions and then have to rapidly decrease them. You want India to figure out ways to avoid locking in high-carbon infrastructure."