Reacción a "Reactions to the detection of record methane concentrations in the atmosphere"

The atmospheric concentrations of CH₄ observed this autumn/winter represent a maximum in the series of measurements available to date. These maximum values have been observed both from space platforms, thus affecting the entire atmospheric column, and at surface level, as is the case of the Izaña Global Atmospheric Watch station (Agencia Estatal de Meteorología), which belongs to the observation programme of the World Meteorological Organisation.

At the Izaña Observatory, the monthly averages of CH₄ surface concentrations recorded during October (1940 ppm), November (1959 ppm) and December 2021 (1952 ppm) are the highest ever since the greenhouse gas observation programme began in 1984.

It is too early to assess the causes of these increases, but studies are currently focused on analysing possible anomalies in the balance between emissions from biological sources and fossil fuels, and their chemical destruction in the atmosphere. However, some preliminary work suggests that anomalous warming of the westernmost part of Siberia and its sea ice may be releasing anomalous CH4 emissions into the atmosphere associated with the melting of permafrost in these areas.

 The climatic effect of these anomalous CH₄ emissions will depend on their duration, i.e., whether they are one-off emissions or a significant and permanent change in observed trends. In the latter case, they may contribute to the observed warming, especially in the medium term.