A group of the world’s top oil and gas companies pledged on Monday to slash emissions of a potent greenhouse gas by a fifth by 2025 in an effort to battle climate change.

The Oil and Gas Climate Initiative (OGCI), which U.S. giants Exxon Mobil and Chevron joined recently, committed to cutting methane emissions to an intensity of 0.25 percent of the group’s total fossil fuel production, it said in a statement.

Such a reduction would equate to 350,000 tonnes of methane annually. It compares with a baseline intensity of 0.32 percent in 2017, excluding new members.

The pledge, which could be lowered to 0.20 percent intensity, echoes targets set individually by members BP, Royal Dutch Shell and Exxon to reduce methane emissions.

“Our aim is to work towards near zero methane emissions from the full gas value chain in support of achieving the goals of the Paris Agreement,” the heads of the OGCI members said in a statement, referring to an international agreement aimed at limiting global warming.

“We have worked to make our ambition concrete, actionable and measurable, helping to ensure that natural gas can realize its full potential in a low-emissions future.”

The OGCI today represents nearly a third of global oil and gas production. It also includes BP, Royal Dutch Shell, France’s Total as well as national oil companies of China, Mexico, Brazil and Saudi Arabia.

In a separate announcement, timed to coincide with the start of Climate Week in New York, OGCI announced the creation of a $100 million China-focused climate investment fund with China National Petroleum Corporation (CNPC).