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There’s a growing sense of excitement among climate change experts, and it’s not about the jaw-dropping low prices of renewable energy that will help reduce the world’s CO2 emissions. Rather, it is an opportunity — the narrowest of windows — to make a huge, measurable reduction in the temperature of earth by reducing emissions of just a few pollutants.

If we time it right, we cool down the planet by 1 degree C this century compared to business-as-usual, keep warming below 2 degrees C, and avoid cooking our planet to a crisp. However, we must act quickly. The timing has to be just right. We need to slash emissions of short-lived climate pollutants — HFCs, methane, soot and tropospheric ozone — now.

The reason that slashing short-lived climate pollutants works so well has everything to do with the fact that they don’t last for long in the atmosphere. Unlike CO2, which lingers for centuries, if we stop emitting short-lived climate pollutants, those chemicals will be removed from the atmosphere quickly: in days to decades. Over the next 20 years, every pound of methane purged from the atmosphere is equivalent to taking out 87 pounds of CO2. And every pound of HFC that degrades is like eliminating thousands of pounds of CO2. This is a very good thing.

The world’s myopic focus on cutting CO2 is understandable, but alone is a risky strategy that may even imperil the planet. The hard truth is cutting CO2 emissions alone won’t cut it. If we don’t slash short-lived climate pollutants too — and quickly — we can’t stay below 2 degrees C. None of this is to contest the need to decarbonize our energy system as soon and as quickly as possible, only that the impact on warming will be slow and only effective decades hence.

Fortunately, there is hope.

In a new book by one of us (Miller), Cut Climate Super Pollutants Now!, we describe how rapid reductions in short-lived climate pollutants can be achieved. There is no single control strategy for halting emissions of these warming agents because they cut across many sectors, including buildings, transportation, agriculture, and energy. Fortunately, efforts are already underway to bring about many proven, cost-effective measures. For example, HFCs are being replaced with climate-friendly alternatives thanks to an international agreement, the Kigali Amendment to the Montreal Protocol of 2016. Thanks to bipartisan legislation passed in December 2020 and subsequent action by EPA, the US is on track to join the rest of the world in slashing HFC production and consumption 85% over the next decades. China also recently signaled its intent to accept the Kigali Amendment and reduce HFCs and other short-lived climate pollutants.

The restoration of Obama era methane regulations will address leaks from new wells, but more needs to be done to address existing production, pipelines, and abandoned fields, ideally through a new international agreement. A new Global Methane Assessment by the Climate and Clean Air Coalition and UN Environment Programme shows that human-caused methane emissions can be reduced by up to 45 per cent this decade, at no net economic cost. Doing so can also reduce formation of ground level smog, in the process preventing 260 000 premature deaths, 775 000 asthma-related hospital visits, 73 billion hours of lost labor from extreme heat, and 25 million tonnes of crop losses annually. These and other common-sense measures can help us slash short-lived climate pollutants quickly.

A key to bringing about the needed additional actions is an approach successfully employed in the Montreal Protocol, the international agreement that successfully addressed the threat of ozone depletion and more recently was amended to reduce use of HFCs. Under the Protocol, a “sectoral approach” was created in which solutions were developed for specific applications of ozone depleting substances — air conditioning, insulating foams, solvents, etc. Industry experts were included in the identification and acceptance of solutions such that not to comply would be a competitive disadvantage. The success of the process illustrates that solution-minded experts exist within industries and can obtain the management support needed for action.

Rapid, dramatic reductions in carbon dioxide are urgently needed and will be key to stabilizing the climate as humanity approaches the end of the 21st century. For now and the next two or three decades, at least equal priority needs to be given to reducing HFCs, methane, and the other short-lived climate pollutants.

Alan Miller is a former climate change officer in the International Finance Corporation (2003–13) and climate change team leader, Global Environment Facility (1997–2003)

Kristen Taddonio is the senior climate and energy advisor to the Institute for Governance & Sustainable Development. Taddonio worked on HFCs and energy efficiency at the Environmental Protection Agency and Energy Department during the Bush and Obama administrations