\u201cWe\u2019re emitting things into the atmosphere that don\u2019t directly warm the planet, but they increase the amount of the greenhouse gases that do directly warm the planet,\u201d said the paper\u2019s lead author, Ilissa Ocko, a former climate advisor for the U.S. Department of State. She\u2019s now senior climate scientist at Spark Climate Solutions, a nonprofit that aims to identify and mitigate sources of unmanaged climate risk.\u00a0<\/p>\n
Carbon monoxide and non-methane volatile organic compounds are the major players named in the paper, indirectly accounting for most of that 15 percent of warming. Black carbon, commonly known as soot, also contributes.<\/p>\n
These drivers of global warming are not addressed by the 1997 Kyoto Protocol, the treaty that set the standard for which gases are tracked in climate policy agreements. Indirect contributions to warming were already being studied at the time, but there wasn\u2019t enough detail to form a basis for policy commitments.\u00a0<\/p>\n
The paper\u2019s authors, who work at groups including the Environmental Defense Fund and include a former U.S. deputy special envoy for climate<\/a>, think there\u2019s now enough information to act. Their work synthesized data, including from the Intergovernmental Panel on Climate Change\u2019s Sixth Assessment Report<\/a>, which was released in 2021.<\/p>\n But integrating carbon monoxide and the other contributors into policy will be an uphill battle.\u00a0<\/p>\n \u201cThe argument for including these gases in a climate accounting framework has been made since the late 1990s,\u201d Vaishali Naik, one of the authors of the 2021 IPCC report and a scientist at the National Oceanic and Atmospheric Administration, wrote in a statement she shared with Inside Climate News. Despite the progress in the generation since then, she notes that \u201cpersistent scientific and political challenges remain.\u201d<\/p>\n One is that there is still work to be done on quantifying the emissions from specific sources and tracing them to their effects on the climate, Naik said.<\/p>\n \u201cThe political climate in many countries is not for adopting even stronger climate rules,\u201d added Michael Gerrard, founder of Columbia University\u2019s Sabin Center for Climate Change Law. It\u2019s enough of a struggle to meet current emission reduction goals that he doubts countries would want to add more pollutants to the list.<\/p>\n But despite the challenges, the paper\u2019s finding \u201chighlights an important missing piece of the climate regulatory picture,\u201d Gerrard said. \u201cIt demonstrates that these pollutants that are not regulated under the climate regime still have some significance.\u201d<\/p>\n The collective impact of the indirect climate pollutants tops all but two of the seven greenhouse gases on the Kyoto list, the study found.<\/p>\n The upside is that unlike No. 1 on the list, carbon dioxide\u2014which stays in the atmosphere for centuries\u2014their contributions are short-lived. Reducing them could slow the rate of global warming in the near future.\u00a0<\/p>\n These potential benefits are more important than ever. \u201cWe\u2019re already seeing damages, so anything we can do to shave off extra fractions of a degree is critical,\u201d said Ocko.\u00a0<\/p>\n While the indirect climate pollutants have been largely under the radar in climate talks, they\u2019re regulated as health-harming air pollutants in multiple countries, including the United States. Carbon monoxide, for instance, contributes to smog.<\/p>\n Ocko, who thinks their impacts shouldn\u2019t be siloed, is optimistic that policy work on the pollutants can slow the rate of global warming while also improving air quality.<\/p>\n \u201cI\u2019m excited to see where all of this goes,\u201d she said, \u201cand hopefully we can uncover new mitigation opportunities to address climate change.\u201d<\/p>\n \t\t\t\t\tAbout This Story<\/p>\n Perhaps you noticed: This story, like all the news we publish, is free to read. That\u2019s because Inside Climate News is a 501c3 nonprofit organization. We do not charge a subscription fee, lock our news behind a paywall, or clutter our website with ads. We make our news on climate and the environment freely available to you and anyone who wants it.<\/p>\n That\u2019s not all. We also share our news for free with scores of other media organizations around the country. Many of them can\u2019t afford to do environmental journalism of their own. We\u2019ve built bureaus from coast to coast to report local stories, collaborate with local newsrooms and co-publish articles so that this vital work is shared as widely as possible.<\/p>\n Two of us launched ICN in 2007. Six years later we earned a Pulitzer Prize for National Reporting, and now we run the oldest and largest dedicated climate newsroom in the nation. We tell the story in all its complexity. We hold polluters accountable. We expose environmental injustice. We debunk misinformation. We scrutinize solutions and inspire action.<\/p>\n Donations from readers like you fund every aspect of what we do. If you don\u2019t already, will you support our ongoing work, our reporting on the biggest crisis facing our planet, and help us reach even more readers in more places? <\/p>\n Please take a moment to make a tax-deductible donation. Every one of them makes a difference.<\/p>\n Thank you,<\/p>\n \t\t\t\t\t![\"\"](\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2026\/06\/Nina-Sablan-300x300.jpg\"\/)
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