This image, provided by NASA Data from six orbits of the Suomi-NPP spacecraft on April 9, was assembled into this perspective composite of southern Africa and the surrounding oceans. Tropical Cyclone Joalane is seen over the Indian Ocean. The image was created by the Ocean Biology Processing Group at NASA’s Goddard Space Flight Center in Greenbelt, Md. (NASA via AP)

In air conditioners, industrial chemicals known as hydrofluorocarbons (HFCs) are powerful refrigerants that help keep humans cool. In the atmosphere, however, they have the opposite effect, trapping the sun’s heat more efficiently than almost any other greenhouse gas.

Now, after years of wrangling, the world’s nations may finally be moving toward setting global limits on the chemicals because of their potential role as a cause of global warming. A round of technical discussions in Bangkok ended Friday with the approval of a work plan that could lead to a global agreement on HFCs, currently among the most commonly used chemical coolants used in air conditioners and refrigerators, before the year’s end.

Diplomats signaled progress toward an international accord after India — long an opponent to a ban on HFCs — reversed course late last week and offered a plan to gradually phase out global production of the chemicals. That step led in turn to an agreement to move forward to formal negotiations in July, with the intention of drafting a final agreement in November, according to officials present at the talks.

“The table is now set for success this year,” said Durwood Zaelke, an environmental law expert and president of the Institute for Governance and Sustainable Development, a Washington-based nonprofit group.

The apparent progress represents a win for the Obama administration, which in particular worked closely with India to address concerns about the availability of alternatives to HFCs. The White House last year announced a voluntary initiative with U.S. manufacturers to speed up the shift from HFCs to more environmentally friendly alternatives.

Secretary of State John F. Kerry, in an interview Thursday, praised Indian Prime Minister Narendra Modi for making a politically difficult choice to move away from HFCs, which are produced in a country in which air conditioning accounts for a major portion of domestic energy consumption.

“It is essential that we get a buy-in on this,” Kerry said, “because HFCs are one of the most dangerous greenhouse gases on Earth — far more damaging and potent that carbon dioxide.”

HFCs initially came into common use in the 1990s following a global ban on chlorofluorocarbons, or CFCs, which were outlawed for damaging Earth’s protective ozone layer. While harmless to ozone, HFCs can be more than 1,000 times more potent as a greenhouse gas that carbon dioxide.

The proposed limits on HFCs are being negotiated by the parties to the Montreal Protocol, the same world body that ratified the ban on CFCs. Previous efforts to expand the agreement to cover HFCs were thwarted because of resistance from oil-rich Persian Gulf nations, as well as India and a few other developing countries. Opponents expressed concern that alternatives to HFCs might not work in extremely hot environments.

Pushing for an international accord are North American and European nations, as well as many African countries and small island states that are particularly vulnerable to effects of climate change.

HFCs represent a relatively small share of the greenhouse gases currently, but the presence in the atmosphere was projected to rise rapidly as developing countries modernize their economies. Removing this group of chemicals could prevent a temperature rise of nearly 1 degree Fahrenheit by the end of the century, Zaelke said.

“The Montreal Protocol can deliver the biggest, fastest, and probably the cheapest climate protection available to the world in the near term,” he said.