LONDON — Rajiv Singh started thinking about how to do his part to fight global warming 15 years ago.

Dr. Singh, a scientist at Honeywell’s lab in Buffalo, began running computer models of tens of thousands of molecular combinations. He was seeking a better refrigerant, one of the most vexing chemicals for the environment.

Refrigerants cool homes, cars and buildings but also warm the planet at a far higher rate than carbon dioxide. Dr. Singh was searching for one stable enough to be useful but that degraded quickly so it did not linger to trap heat in the atmosphere.

“You have to hit the chemistry books,” he said in a recent interview.

As product names go, HFO-1234yf, the refrigerant he played a crucial role in developing, does not roll off the tongue. But it is one of the most important alternatives to hydrofluorocarbons, or HFCs, which have long been used in air-conditioners and refrigerators and which contribute greatly to climate change. On Oct. 15, in Kigali, Rwanda, more than 170 countries reached an agreement as part of the Montreal Protocol to curb the use of HFCs.