Toronto ? Governments of almost 200 countries have agreed to speed the elimination of a major greenhouse gas that depletes ozone, U.N. and Canadian officials said Saturday, describing a deal they said was a significant step toward fighting global warming.

The agreement reached Friday night will accelerate a treaty to freeze and phase out hydrochlorofluorocarbons, or HCFCs, which are used in home appliances, some refrigerators, hair sprays and air conditioners, said Nick Nuttall, spokesman for the U.N. Environment Program.

“With this plan of an accelerated freeze and accelerated phaseout, we could have potentially significant benefits arising in terms of combating climate change and ozone loss,” Nuttall said. “It’s a remarkable change in how we view the issue of climate change.”

The treaty known as the Montreal Protocol was originally established in the Canadian city in 1987 to protect the ozone layer from destructive chemicals. It was negotiated by 191 countries to cut back on chemicals blamed for destroying the ozone layer.

The member nations, gathering in Montreal again 20 years later, agreed to freeze production and consumption of HCFCs in 2013.

Developed countries have agreed to reduce production and consumption by 75 percent by 2010 and by 90 percent by 2015 with final phaseout in 2020 – 10 years sooner than the earlier agreement. Developing countries have agreed to cut production and consumption by 10 percent in 2015; by 35 percent by 2020 and by 67.5 percent by 2025 with a final phaseout in 2030.

In Washington, the White House said the agreement would cut in half the potential emissions of remaining chemicals harmful to the ozone.

“This action will not only speed up recovery of the ozone layer, but also represents one of the most significant new global actions to confront climate change by reducing the greenhouse gas profile of the phased-out substances,” a White House statement said.

The final agreement is a combination of proposals by a number of countries, including the United States.

HCFCs emerged in the 1990s to phase out the older and more ozone-damaging chlorofluorocarbons, or CFCs, used in air conditioners, refrigerators and hair sprays.

CFCs were blamed for a hole in the ozone layer, the atmospheric layer that helps protect against the sun’s most harmful rays and traps the Earth’s heat. The hole contributed to a rise in average surface temperatures.

However, while HCFCs are less destructive to the ozone layer, they are considered potent greenhouse gases that harm the climate – up to 10,000 times worse than carbon dioxide emissions.