The World Meteorological Congress has approved the new Global Greenhouse Gas Watch (GGGW) initiative, which will fill critical information gaps and provide an integrated, operational framework to bring all space-based and surface-based observing systems, as well as modeling and data assimilation capabilities, under one roof.
GGGW will build on WMO’s experience in coordinating international collaboration in weather prediction and climate analysis and its long-standing activities in greenhouse gas monitoring and research under the auspices of the Global Atmosphere Watch and its Integrated Global Greenhouse Gas Information System.
Many international and national activities dealing with greenhouse gases are supported mainly by the research community. At present, there is no comprehensive, timely international exchange of surface and space-based greenhouse gas observations or modeling products.
Prof. Petteri Taalas, WMO secretary-general, said, “We know from our measurements that greenhouse gas concentrations are at record levels – in fact, higher than at any time over the last 800,000 years. The increase in carbon dioxide levels from 2020 to 2021 was higher than the average growth rate over the past decade, and methane saw the biggest year-on-year jump since measurements started.
“But there are still uncertainties, especially regarding the role in the carbon cycle of the ocean, the land biosphere and the permafrost areas,” he added. “We therefore need to undertake greenhouse gas monitoring within an integrated Earth system framework in order to be able to account for natural sources and sinks, both as they currently operate and as they will change as a result of a changing climate. This will provide vital information and support for implementation of the Paris Agreement.”
Dr Lars Peter Riishøjgaard, deputy director of the WMO’s infrastructure department, said, “WMO’s decision on the generational challenge of climate change mitigation is a historic step. Internationally coordinated global greenhouse gas monitoring open to all and operating under WMO’s policy of free and unrestricted exchange of data will provide valuable, timely and authoritative information on greenhouse gas fluxes to the UNFCCC parties, which will help them in their efforts to mitigate climate change. There is very strong support from the science community and private sector for the new Global Greenhouse Gas Watch.”
In its initial configuration, it is envisaged that the GGGW will consist of four main components:
- A global set of surface-based and satellite-based observations of CO2, CH4 and N2O concentrations, total column amounts, partial column amounts, vertical profiles and fluxes, and 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;
- Associated with the models, data assimilation systems that optimally combine the observations with model calculations to generate products of higher accuracy.
As an output, the infrastructure will produce gridded net monthly fluxes of CO2, CH4 and N2O at a special resolution of 100 x 100km with a minimum possible delay. These outputs can drive multiple applications, from contribution to the global stocktake to assessment of the fluxes from individual facilities or landscapes.
