Durwood Zaelke, President of the Institute for Governance & Sustainable Development (IGSD), has spent most of his life fighting big environmental battles. He is a lawyer. He has taken on toxic waste cases. He helped investigate Love Canal and the Three Mile Island nuclear accident when he worked at the US Department of Justice. He later helped build global environmental law groups. Today, he runs IGSD, based in Washington and Paris. His focus now is clear. Cut fast warming gases. Buy time for the planet. Speaking during WSDS 2026, Zaelke said the world is still too focused on carbon dioxide alone.

“For decades, people said CO2 is the biggest piece, so maybe that should be our focus,” he said. “But nearly half of warming comes from non-CO2.”

He pointed out that short-lived climate pollutants like methane, black carbon, hydrofluorocarbons and ground-level ozone are non-CO2 gases that are also responsible for greenhouse emissions. The gases remain airborne for a shorter duration than carbon dioxide does. However, they trap much more heat compared to CO2 when they are in the environment.

He said about 55 per cent of past warming came from CO2 and 45 per cent from these other gases. But looking ahead to 2050, cutting those other gases can slow warming much faster. The reduction of other greenhouse gases will result in faster climate change mitigation until 2050. He described carbon reduction as a marathon because it requires extensive time to complete the process. The world needs to completely stop carbon emissions by 2050 to achieve only 0.1 degrees of warming reduction, which will occur by mid-century. The elimination of methane emissions together with other short-lived pollutants will prevent at least 0.4 degrees of warming between now and 2050.. Methane alone could cut about 0.3 degrees. And you would see that benefit in the 2040s. “Big. Fast,” he said. “And the world is not paying enough attention to it.”

There is the Global Methane Pledge from COP26. He called it good, but not enough. “It’s just a pledge,” he said. What is needed now is something binding. Zaelke often points to the Montreal Protocol to show that strong treaties can work. Signed in 1987 to protect the ozone layer, it required countries to reduce harmful chemicals on a clear timetable. The world can measure those chemicals in the air. If a country breaks the rules, others can see it.

Since then, nearly 100 dangerous chemicals have been phased out. The treaty also created a fund to help poorer countries comply. India played a key role in shaping that funding system in 1990, led by negotiator K. Madhava Sarma. “It works,” Zaelke said of the Montreal model. “It’s mandatory.”

By contrast, the Paris Agreement is mostly voluntary. Countries say what they plan to do. That helps keep climate in the news. But, he said, voluntary action is not enough anymore. He sums up the crisis in three words. Temperature. Time. Tipping points.

“It’s too hot. There’s too little time. Tipping points are too close,” he said. The fastest way to slow warming now is to cut methane, especially from oil and gas. Gas flaring, he said, is like burning cash. It wastes fuel and heats the planet at the same time.

Politics can slow things down. When leaders question climate science, progress gets harder. But Zaelke says climate action finds other paths. US states such as California and New York continue to act. Europe is still strong. Canada is moving ahead. Clean energy keeps growing.

Zaelke completed his studies at UCLA and Duke Law School. In his early days, he taught environmental law and authored several leading textbooks. In 2009 and again in 2022, he worked with top scientists to publish research on fast climate action.

Since then, his message has not changed. Cutting carbon dioxide is essential. But if governments ignore methane and other fast-warming gases, they are wasting precious time. Governments should act quickly to reduce methane and other fast-warming gases instead of delaying action.

And time, he said, is something the planet does not have much of left.