Letter in Support of Declaration on Reducing Atmospheric Methane

We, the undersigned support the Declaration on Reducing Atmospheric Methane, which would commit signatories — national and subnational governments, and international bodies — to take key steps to reduce methane emissions and remove atmospheric methane, in order to lower atmospheric methane concentrations to preindustrial levels.

Current methane levels are at 800,000-year highs and rising rapidly. Atmospheric methane concentrations jumped more last year than in any year of the past 35. According to the latest IPPC report1, methane has caused one third of global warming (as observed on average for 2010 to 2019, relative to average temperatures in the late 1800s), and has contributed at least half as much warming as carbon dioxide.

Methane emissions from anthropogenic sources are rising quickly, and continued warming is also likely to intensify biogenic emissions from wetlands. While it’s critical to cut methane emissions as deeply as possible, including in the fossil fuel sector, the largest source of anthropogenic methane emissions globally is the agricultural sector, whose emissions are impossible to eliminate completely.

At the same time, about 40% of methane emissions are from natural sources such as wetlands. We must aggressively mitigate methane emissions wherever we can, while conserving and restoring the ecological functions of wetlands and other ecosystems. But we must also address natural and anthropogenic methane emissions that we can’t effectively reduce or eliminate.

In April 2021 leading climate scientists, atmospheric scientists and other experts issued a statement urging national and global leaders to take effective measures to achieve a rapid reduction in atmospheric methane levels. In addition to reducing methane emissions, they called for more research on scalable ways of removing methane from the atmosphere. Some emerging methods for removing methane from the atmosphere were discussed in the most recent IPCC report, which also cited current research about them2.

The April statement called upon all countries to commit to cutting methane emissions aggressively, to fund research on methane mitigation and removal, and to frame and implement global governance to ensure full and proper implementation of such methods in order to return to atmospheric methane concentrations to preindustrial levels.

Now it’s time for leaders to act, and take concrete steps toward these goals. The Declaration on Reducing Atmospheric Methane lays out such steps that can be taken now, and a framework for researching a range of potential methane solutions and implementing those that prove safe and effective, including but not limited to the ones the Declaration mentions by name. We urge national governments and other jurisdictions to adopt it.

Furthermore, given that rising methane concentrations contribute significantly to global warming, ecosystem damage and biodiversity loss, we urge parties to the United Nations Framework Convention on Climate Change, the Convention on Biological Diversity, and other relevant treaties and agreements to take swift, effective action on methane emissions reduction and atmospheric methane removal, incorporating as appropriate the goals and framework of the Declaration on Reducing Atmospheric Methane.


1 IPCC, 2021: Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu and B. Zhou (eds.)]. Cambridge University Press. In Press.

2 Ibid. Proposals to remove CH4 from the atmosphere are emerging (de Richter et al., 2017; Jackson et al., 2019). CH4 removal methods seek to capture CH4 directly from ambient air similarly to DACCS for CO2 using for example zeolite trapping, but instead of storing it CH4 would be chemically oxidized to CO2 (Jackson et al., 44 2019).

Scientists and civil society organizations are encouraged to sign on.  To add your signature, please complete the form below.