World envoys reached an agreement Saturday on a timetable for the phase-out of potent greenhouse gases used in refrigerators and air conditioners, a major step in curbing global warming.

The amendment to the 1987 Montreal Protocol on protecting the ozone layer was greeted by applause from exhausted envoys who had worked through the night in the Rwandan capital Kigali to put the final touches on the deal to phase out production and consumption of hydrofluorocarbons (HFCs).

Leonardo DiCaprio has issued an impassioned call for immediate action on climate change in "Before the Flood", a documentary film making its European premiere in London on Saturday.

Hopes were high Friday that world envoys at a meeting in Rwanda will agree a deal to phase out the use of a potent greenhouse gas used in refrigerators and air conditioners.

Australia's permanent sub-Antarctic research base at World Heritage-listed Macquarie Island has won a reprieve from closure and will instead get a multi-million dollar revamp, the government said Friday, in a boost for science.

The Australian Antarctic Division announced in September the station on the island -- which lies in the Southern Ocean between Australia and Antarctica -- would shut after almost seven decades due to environmental contamination concerns and ageing infrastructure.

Greenhouse gases that are more powerful than carbon dioxide are the focus of a global gathering this week in Africa. Experts say cutting hydrofluorocarbons, or HFCs, is the fastest way to reduce global warming. The United States is among the countries that want the world to quickly phase out the use of HFCs, and Secretary of State John Kerry is arriving Thursday to encourage a deal. Here's a look at a potential global climate agreement that has been described by the National Resources Defense Council as "the world's biggest climate protection achievement in the year after Paris."

IT'S NOT ABOUT THE OZONE LAYER

The US government reiterated its request Monday that construction of an oil pipeline in North Dakota be paused, while authorities consider the impacts of its route on a Native American tribe.

Energy efficiency accelerated last year despite low oil prices, according to a report from the International Energy Agency published Monday, driven in large part by gains in China.

Emergency workers sealed off a portion of New Delhi's international airport Sunday after officials suspected a consignment containing radioactive material had leaked, a police officer said. 

At first glance there's nothing out of the ordinary about the regional airport in George, a town of just 150,000 residents on South Africa's south coast.

Envoys from nearly 200 nations meet in Kigali next week to discuss ridding the world of HFCs, gases introduced to save the ozone layer only to unwittingly assail Earth's climate.

Observers are hopeful that after years of talks, countries are poised to commit to phasing out hydrofluorocarbons, rolled out in the 1990s to replace chlorofluorocarbons (CFCs) in refrigerators, aerosols, air conditioners and foam insulation.