2024-07-11 JRC-IPCC-TFI-NGHGI Ispra

The Global Greenhouse Gas Watch
Gianpaolo Balsamo and G3W team (WMO)

Greenhouse gas emissions, greenhouse gas concentrations and global mean temperature all continue to rise, and in order to stay within the temperature limits stipulated in the text of the Paris Agreement, mitigation action is becoming increasingly urgent However, the fact that we cannot quantitatively and reliably predict future GHG concentrations – and therefore climate scenarios – from assumed future emission pathways is a complicating factor when designing mitigation action. Even more problematic is the assessment the impact or effectiveness of many current or proposed mitigation activities, since it often has to be based on indirect measures such as avoided emissions with respect to a hypothetical baseline, or carbon stored, e.g. in the land or ocean biosphere, neither of which can be directly linked to atmospheric concentrations.

In order to provide robust, actionable data that will help Parties to the UNFCCC and other stakeholder design and develop mitigation action and monitor its effectiveness, the World Meteorological Congress in May 2023 endorsed the Global Greenhouse Gas Watch (G3W) as an internationally coordinated framework to provide near-real time GHG (CO2, CH4 and N2O) flux estimates based on atmospheric modelling and atmospheric observations.  At COP28 in Dubai, the G3W was formally recognized by the Subsidiary Body for Scientific and Technological Advice (SBSTA-59) to the UNFCCC.

Currently a G3W implementation plan is in development, with the aim of submitting it for approval by the WMO Executive Council by mid-2024. Some of the key elements of the plan are a significant strengthening of the global GHG observing capabilities, improved near-real time exchange of both observational data and flux estimates, and routine intercomparision of model output among all participating flux estimation centers.

The presentation will introduce the overall G3W development timeline which aims for a full operational capability to be ready for the Second Global Stocktake in 2027-28, with the main focus on the near-time activities planned for 2024-25.

Global Greenhouse Gas Watch (G3W)

The G3W aims to establish and support a coordinated global operational greenhouse gases (GHGs) observation network of space-based (e.i. satellites) and surface-based sensors (e.i. insitu stations) that can accurately estimate GHGs fluxes, focusing on carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), the top three gases that are responsible for global warming and the associated impacts that manifest in extreme weather.

By integrating several sources of quality-controlled observations in earth system models that consider physical, chemical, and biological processes reaching far beyond physical atmospheric and oceanic processes, the natural and anthropogenic sources and sinks of GHGs can be better monitored and provide support to existing efforts.

The integration of observations and modelling (also leveraging Artificial Intelligence) is coordinated within G3W, and count on well-established operating centres to produce consolidated and continuous global information on the total fluxes and concentrations of GHGs, with guidance on the accuracy of the data and their interoperability all along the value-chain.

The G3W implementation plan has outlined a staged approach, beginning with the G3W-IPP, the Implementation and Pre-Operational Phase from 2024 to 2027, followed by the G3W-IOP Initial Operational Phase from 2028 to 2031, and finally, transitioning to the G3W-EOP Enhanced Operational Phases from 2032 to 2050.

The Implementation and Pre-Operational Phase focus on the Research to Operation transition including the necessary standardisation and benefit from the World Meteorological Organization's (WMO’s) long-term efforts in coordinating greenhouse gas GHG observations and research under the Global Atmospheric Watch (GAW) Programme, the Intergovernmental Panel on Climate Change (IPCC), and the Global Climate Observing System Programme, as well as on the experience of the intergovernmental commissions for infrastructure and services that benefit from expertise and collaboration of the 193 Members of WMO.

The goal of G3W is to ensure that key observation-based information is available with agreed standards, following the principle of joint contribution and shared benefits, supporting all Nations in the implementation of the Paris Agreement climate targets, and serving the Enhanced Transparency Framework processes of the United Nations Climate Change UNFCCC.