The World Meteorological Congress – the supreme body of World Meteorological Organization (WMO) – has approved a new greenhouse gas (GHG) monitoring initiative to support implementation of the Paris Agreement on climate change. The Global Greenhouse Gas Watch aims to “fill critical information gaps and provide an integrated, operational framework which brings under one roof all space-based and surface-based observing systems, as well as modelling and data assimilation capabilities.”

The initiative seeks to facilitate comprehensive, timely, free, and unrestricted international exchange of surface- and space-based GHG observations and modeling products. It will build on WMO’s experience in coordinating collaborative efforts in weather prediction and climate analysis and on GHG monitoring and research carried out under the 1989 Global Atmosphere Watch and its Integrated Global Greenhouse Gas Information System.

According to a WMO press release, the Global Greenhouse Gas Watch will consist of four main components:

• A comprehensive sustained, global set of surface-based and satellite-based observations of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) concentrations, total column amounts, partial column amounts, vertical profiles, and fluxes and of supporting meteorological, oceanic, and terrestrial variables, internationally exchanged as rapidly as possible, pending capabilities and agreements with the system operators;
• Prior estimates of the GHG emissions based on activity data and process-based models;
• A set of global high-resolution Earth System models representing GHG cycles; and
• Associated with the models, data assimilation systems that optimally combine the observations with model calculations to generate products of higher accuracy.

Highlighting that GHG concentrations are at record levels and that the increase in CO2 levels from 2020-2021 “was higher than the average growth rate over the past decade,” with methane seeing the biggest year-on-year increase since measurements began, WMO Secretary-General Petteri Taalas pointed to uncertainties surrounding the role of the ocean, the land biosphere, and the permafrost areas in the carbon cycle.

Taalas said GHG monitoring within an integrated Earth System framework to account for natural sources and sinks as they currently operate and as they will change as a result of climate change, “will provide vital information and support for implementation of the Paris Agreement.”

WMO Deputy Director for infrastructure Lars Peter Riishojgaard said WMO-coordinated global GHG monitoring that is free and open to all “will provide valuable, timely and authoritative information on [GHG] fluxes” to countries, supporting them in their climate change mitigation efforts. [Global Greenhouse Gas Watch] [UN News Story]