In a new report, the United Nations Environment Programme (UNEP) concludes that global warming is expected to exceed 1.5°C within the next few years. This makes two questions increasingly important: how high will temperatures rise, and how long will the exceedance last? In a separate international study published earlier this year, Chalmers researcher Daniel Johansson and his colleagues investigated a potential future method for limiting peak warming: removing methane directly from the atmosphere.
What are the main findings of your study – and what role could methane removal play if global warming exceeds 1.5°C?
”Methane removal could provide a way to temporarily reduce peak warming, but it is not a permanent solution. If we stop removing methane, the warming returns. It is therefore important to see methane removal as a potential complement to deep emissions reductions and permanent carbon dioxide removal, not as a shortcut around them,” says Daniel Johansson, Professor at the Department of Environmental and Energy Sciences.
Methane already in the atmosphere
Reducing methane emissions is an important climate measure. The study investigates a different and far more experimental possibility: removing or breaking down methane that is already in the atmosphere.
Carbon dioxide is the most important long-lived greenhouse gas driving global warming. Methane is present at much lower concentrations and remains in the atmosphere for a shorter period, but it is also a very powerful greenhouse gas. Reducing methane concentrations can therefore affect global temperatures more quickly than reducing carbon dioxide concentrations.
The researchers compare three different types of climate intervention:
Atmospheric Methane Removal (AMR) – removing or breaking down methane that is already in the atmosphere, for example by enhancing chemical reactions that break down atmospheric methane, increasing microbial methane uptake in ecosystems, or using engineered reactors to oxidise methane.
Carbon Dioxide Removal (CDR) – removing carbon dioxide from the atmosphere and storing it over the long term, for example in geological formations underground.
Solar Radiation Management (SRM) – methods that reduce the amount of solar energy reaching the Earth's surface, for example by introducing particles high into the atmosphere that reflect some of the incoming sunlight.
The model calculations show that methane removal could lead to a relatively rapid reduction in global temperature. If methane removal is stopped, temperatures begin to rise again, although the rebound in warming is less abrupt than when solar radiation management is terminated.
With carbon dioxide removal, the climate effect persists because the model assumes that the carbon dioxide already removed from the atmosphere is stored permanently.
What implications could methane removal have for solar radiation modification?
One question for future research is what role atmospheric methane removal (AMR) could play in relation to solar radiation modification in the future
Could AMR become an alternative way of limiting peak warming – and what do researchers need to find out before we can say whether this is possible?
”Solar radiation management is associated with significant risks and uncertainties and is therefore a highly controversial option. At the same time, the consequences of warming above 1.5°C are serious. If, in the future, we are able to remove methane from the atmosphere, this could be a way to reduce peak warming and thereby lessen the consequences of exceeding the 1.5°C level. But much more research is needed before we know whether this is actually feasible. We still know very little about how methane could be removed from the atmosphere on a large scale using technological or biological methods. One fundamental challenge is that methane concentrations are so low: only around two parts per million of the atmosphere consist of methane,” says Daniel Johansson.
The study also shows that methane removal interacts with atmospheric chemistry. The concentrations of other air pollutants can influence interactions between methane and, among other things, ozone, with potential consequences for the climate, air quality, human health and ecosystems.
The study uses a simplified global climate model. More advanced models are needed to better understand these interactions.
Technologies for removing methane from the atmosphere are still at an early stage of research. The study therefore investigates the potential climate effects and risks of such an intervention – rather than whether AMR is ready to be used as a climate measure.
The study, Atmospheric methane removal as a third climate intervention: termination risks and air pollutant effects, was published on 24 June 2026 in npj Climate Action, part of the Nature Portfolio.
Researchers involved in the study:
Katsumasa Tanaka – Laboratoire des Sciences du Climat et de l’Environnement (LSCE), IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France; samt Earth System Division, National Institute for Environmental Studies (NIES), Tsukuba, Japan.
Weiwei Xiong – Laboratoire des Sciences du Climat et de l’Environnement (LSCE), IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France.
Didier A. Hauglustaine – Laboratoire des Sciences du Climat et de l’Environnement (LSCE), IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France.
Daniel J. A. Johansson – Department of Environmental and Energy Sciences, Division of Physical Resource Theory, Chalmers University of Technology, Gothenburg, Sweden.
Nico Bauer – Potsdam Institute for Climate Impact Research (PIK), Potsdam, Germany.
Philippe Bousquet – Laboratoire des Sciences du Climat et de l’Environnement (LSCE), IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France.
Philippe Ciais – Laboratoire des Sciences du Climat et de l’Environnement (LSCE), IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France.
Renaud de Richter – Tour-Solaire, Montpellier, France.
Marianne T. Lund – CICERO Center for International Climate Research, Oslo, Norway.
Ragnhild B. Skeie – CICERO Center for International Climate Research, Oslo, Norway.
Eric Zusman – Institute for Global Environmental Strategies (IGES), Hayama, Japan.
Unep Report:
- Professor, Physical Resource Theory, Environmental and Energy Sciences
