{"id":15211021,"date":"2026-07-15T18:00:43","date_gmt":"2026-07-15T22:00:43","guid":{"rendered":"https:\/\/www.inthacity.com\/news\/these-clumped-molecules-could-offer-clues-about-earths-climate\/"},"modified":"2026-07-15T18:33:26","modified_gmt":"2026-07-15T22:33:26","slug":"these-clumped-molecules-could-offer-clues-about-earths-climate","status":"publish","type":"post","link":"https:\/\/www.inthacity.com\/news\/these-clumped-molecules-could-offer-clues-about-earths-climate\/","title":{"rendered":"These \u201cClumped\u201d Molecules Could Offer Clues About Earth\u2019s Climate"},"content":{"rendered":"
\"Two<\/figure>\n

Methane is one of the most abundant greenhouse gases on Earth, and, when compared with carbon dioxide, it is 28 times more potent<\/a> at trapping heat in the atmosphere.<\/p>\n

As the climate warms, it\u2019s increasingly urgent to understand where methane comes from. Researchers can analyze the ratios of different carbon isotopes within methane to learn<\/a> whether that sample came from fossil fuels or from other sources, such as wetlands<\/a> or agriculture.<\/p>\n

\n
\n

\u201cI think this could end up being a landmark study.\u201d<\/p>\n<\/blockquote>\n<\/figure>\n

Sometimes, though, even these isotopic fingerprints leave room for uncertainty. New research examined several hundred liters of air gathered from compacted snow in Greenland in an even more precise way. The study, which marks the first time researchers have reconstructed the clumped isotopologue signature of atmospheric methane from past air, was published today<\/a> in Science Advances<\/em>.<\/p>\n

\u201cI think this could end up being a landmark study,\u201d Edwin Schauble<\/a>, a geochemist at the University of California, Los Angeles, who was not involved in the research, told Eos<\/em> via email. \u201cMethane is such an important greenhouse gas and tracer of the carbon cycle that the prospect of getting a better understanding of its history and future is exciting.\u201d<\/p>\n

The Nitty-Gritty<\/h3>\n

Methane (CH4<\/sub>) is made up of one carbon and four hydrogen molecules.<\/p>\n

Isotopes<\/a>, of course, refer to atoms of the same chemical element that have different numbers of neutrons. For instance, carbon naturally occurs in three isotopes: carbon-12, carbon-13, and carbon-14, with carbon-12 being the most common. Hydrogen has three naturally occurring isotopes, including deuterium (which has one proton and one neutron).<\/p>\n

The word \u201cisotopes,\u201d explained Jiayang Sun<\/a>, a geochemist who was a Ph.D. student at the University of Maryland when he coauthored the new paper, refers to elements at the atomic level.<\/p>\n

\u201cBut when we say \u2018isotopologue,\u2019 it\u2019s a word on the molecular level,\u201d he said. \u201cFor clumped isotopologues, it\u2019s two or more rare isotopes substituted into one molecule.\u201d<\/p>\n

This could mean that the carbon-12 in a methane molecule is replaced with a carbon-13 and one of the molecule\u2019s hydrogens is replaced with deuterium, or it could mean that two of the hydrogens in the same molecule are replaced with two deuteriums.<\/p>\n

\u201cIn some cases, the information from clumped isotopologues gives you information that\u2019s independent from that provided by the straight isotopes,\u201d said James Farquhar<\/a>, a geochemist at the University of Maryland. \u201cIt gives us a little bit of a better understanding, or better constraints.\u201d<\/p>\n

Higher anthropogenic emissions result in lower clumped methane concentrations. However, clumped methane molecules take many years to reach equilibrium, so an increase in methane emissions might not show up in the clumped isotope signal for decades.<\/p>\n

New Insights from Old Air<\/h3>\n

Modeling reflects that emissions of methane have changed over the course of the industrial era. NOAA data<\/a> show that atmospheric methane levels have risen since the 1980s, with a plateau from 1999 to 2006. The new study\u2019s researchers wanted to take a closer look at these changes by examining the clumped isotopes in air samples from the past.<\/p>\n

\u201cThe overall trend is kind of clear, but when it comes to detailed allocation of total emissions to each source\u2026the uncertainties related to that are still high,\u201d Sun said.<\/p>\n

Because methane makes up only about 2 parts per million<\/a> of air, and clumped isotopes only represent part of that, the team would need a lot of air to undertake this investigation.<\/p>\n

\n
\"Three
A team of researchers gathers a firn sample. Credit: Thomas R\u00f6ckmann<\/figcaption><\/figure>\n<\/div>\n

But where do you get several hundred liters of decades-old air? One method is to use air found in firn<\/a>, compacted snow that is the intermediate stage between snow and glacial ice. Researchers from Utrecht University, including atmospheric scientists Malavika Sivan<\/a> and Thomas R\u00f6ckmann<\/a>, happened to have several hundred liters on hand.<\/p>\n

The samples were gathered in 2018 as part of the East Greenland Ice-Core Project<\/a> (EastGRIP). A team of researchers, including R\u00f6ckmann<\/a>, drilled a hole into the ice and inserted a 5-meter-long bladder and a set of three tubes. The bladder was inflated to seal the hole and prevent contamination. The tubes then pulled 30-year-old air out from the pores within the firn and pumped it into containers on the surface.<\/p>\n

The Utrecht team was interested in examining the clumped isotope levels, but they didn\u2019t have a mass spectrometer that could conduct such analysis on their relatively limited sample size. This made the University of Maryland researchers, who had the spectrometer but not the samples, a perfect partner.<\/p>\n

After measuring the samples, the team used modeling to conclude that clumped methane reached a low in approximately 1993.<\/p>\n

\u201cOur model suggests that was caused by the increased anthropogenic methane emissions during the industrial period (the 1800s),\u201d Sivan wrote in an email to Eos<\/em>. \u201cClumped methane molecules take a very long time to equilibrate after such perturbations, hence the lag in the signal.\u201d<\/p>\n

Future Methane Levels<\/h3>\n

By helping us understand more about our past, this work could be combined with traditional bulk isotope measurements to improve modeling of future atmospheric methane levels.<\/p>\n

\n
\n

\u201cNot only do their results tell us much more about methane\u2019s past history, their findings may also be very helpful in targeting pathways to bring methane\u2019s rise under control.\u201d<\/p>\n<\/blockquote>\n<\/figure>\n

\u201cIt provides the data that would be needed to understand how we got here in terms of the isotopic compositions, and that\u2019s a constraint that will be of value if we\u2019re going to make interpretations about changes that happen in the future,\u201d Farquhar said.<\/p>\n

Euan Nisbet<\/a>, an Earth scientist and professor emeritus at Royal Holloway University of London, said that clumped isotope research is \u201cvery much the forefront\u201d of improving understanding of the global methane budget, and that this new work is \u201ca very fine study.\u201d<\/p>\n

\u201cNot only do their results tell us much more about methane\u2019s past history, their findings may also be very helpful in targeting pathways to bring methane\u2019s rise under control,\u201d he said.<\/p>\n

\u2014Emily Gardner (@emfurd.bsky.social<\/a>), Associate Editor<\/p>\n

Citation:<\/strong> Gardner, E. (2026), These \u201cclumped\u201d molecules could offer clues about Earth\u2019s climate, Eos, 107, <\/em>https:\/\/doi.org\/10.1029\/2026EO260235<\/a>. Published on 15 July 2026.<\/h5>\n
Text \u00a9 2026. AGU.\u00a0CC BY-NC-ND 3.0<\/a>
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.<\/h6>\n

Source: Science \u2013 eos<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Researchers investigated concentrations of clumped methane isotopes to learn more about how levels of the potent greenhouse gas have changed over the industrial era.<\/p>\n","protected":false},"author":1,"featured_media":15211023,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"footnotes":""},"categories":[218],"tags":[],"class_list":["post-15211021","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-science"],"featured_image_urls":{"full":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1.jpg",1024,576,false],"thumbnail":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-300x169.jpg",300,169,true],"medium":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-620x349.jpg",620,349,true],"medium_large":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-768x432.jpg",768,432,true],"large":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-940x529.jpg",940,529,true],"1536x1536":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1.jpg",1024,576,false],"2048x2048":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1.jpg",1024,576,false],"post-thumbnail":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-998x576.jpg",998,576,true],"ignition_item":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-670x446.jpg",670,446,true],"ignition_item_lg":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1.jpg",1024,576,false],"ignition_article_media":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-510x510.jpg",510,510,true],"ignition_minicart_item":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-160x160.jpg",160,160,true],"profile_24":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-24x24.jpg",24,24,true],"profile_48":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-48x48.jpg",48,48,true],"profile_96":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-96x96.jpg",96,96,true],"profile_150":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-150x150.jpg",150,150,true],"profile_300":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/07\/15211021-grip-camp-1024x576-1-300x300.jpg",300,300,true]},"author_info":{"display_name":"news.iNthacity","author_link":"https:\/\/www.inthacity.com\/news\/author\/atombo\/"},"category_info":"Science<\/a>","tag_info":"Science","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/posts\/15211021","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/comments?post=15211021"}],"version-history":[{"count":1,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/posts\/15211021\/revisions"}],"predecessor-version":[{"id":15211022,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/posts\/15211021\/revisions\/15211022"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/media\/15211023"}],"wp:attachment":[{"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/media?parent=15211021"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/categories?post=15211021"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/tags?post=15211021"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}