G3W Overview
The Global Greenhouse Gas Watch (hereafter G3W) aims at providing global products of monthly net fluxes of CO2, CH4, and N2O with 1x1 degree resolution, aiming to reduce uncertainties and increasing the reliability of the GHGs monitoring systems.
In 2023, the 19th World Meteorological Congress (Cg-19, Resolution 5) approved a concept note for the G3W, which aims to support WMO Members' decision-making in mitigation actions to implement the Paris Agreement by providing more accurate information.
This concept has been developed in a close collaboration between WMO and partner organizations dealing with greenhouse gases and carbon cycle. In 2024, INFCOM-3 approved the G3W Implementation Plan (IP), and the 78th Executive Council (EC-78) endorsed the plan to officially commence its Pre-Operational Phase (IPP) for the period 2024-2027.
The G3W fills critical information gaps and provides an integrated, operational framework that brings together all observing systems, as well as modelling and data assimilation capabilities in relation to greenhouse gas monitoring, striving to reduce the uncertainty in assessing the efficacy of climate action.
Background
The Paris Agreement, adopted in 2015 under the United Nations Framework Convention on Climate Change (UNFCCC), is a landmark international treaty to combat climate change. One of its central objectives is to limit the global average temperature rise to well below 2°C above pre-industrial levels, with efforts to limit the increase to 1.5°C. This temperature goal was established by the Parties to prevent the most severe impacts of climate change, such as extreme weather events, rising sea levels, and loss of biodiversity. Achieving this target requires global cooperation and significant reductions in greenhouse gas emissions, along with measures to enhance resilience and support climate adaptation.
During the twenty-seventh Conference of the Parties (COP27 in Sharm El Sheikh, 6th–20th November 2022), the Parties recognized that “{…} limiting global warming to 1.5°C requires rapid, deep and sustained reductions in global greenhouse gas emissions of 43% by 2030 relative to the 2019 level;”. It further “Emphasizes {…} the need to enhance coordination of activities by the systematic observation community and the ability to provide useful and actionable climate information for mitigation, adaptation and early warning systems, as well as information to enable understanding of adaptation limits and of attribution of extreme events”. Access to improved harmonized information on the concentrations and budgets of GHGs, in part already collected by existing infrastructures, is needed to help countries to establish their commitments and to monitor progress toward meeting emission reductions targets. Responding to COP27 call requires an effort from multiple agencies and communities to work together, to establish new or to update existing agreements and arrangements between international and national agencies and different bodies under WMO.
The 1st Global Stocktake4 (GST-1) presented at COP28, already made use of some of the systems that will be foundational for G3W and highlighted the limited progress towards meeting the goals of the Paris Agreement, and this outcome underpins the need for accelerating ambition in their next round of climate action plans due in 2025.
Goal
G3W will create a technical framework for member countries to cooperate on production of the Greenhouse Gas (GHG) data products that would help to understand and access the impact of mitigation actions taken by the Parties to the UNFCCC and the Paris Agreement on the state of climate. Such information will be produced in a timely manner and will consider both human and natural influences on the levels of greenhouse gases in the atmosphere.
Initial focus will be on the three most important GHGs influenced by human activities, namely carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Increasing abundances of these gases in the atmosphere are the dominant cause of the observed climate change and related impacts according to the Intergovernmental Panel on Climate Change. Recent increases in atmospheric concentrations of CO2, CH4 and N2O have been documented to be driven by human activities.
It is anticipated that ongoing and new research to develop capabilities to further separate these net fluxes into source-apportioned emissions will lead to additional operational products in the future. Per WMO's data policy and in the interest of maintaining transparency as required under the Paris Agreement, the data are expected to be made available to all users worldwide on a free and unrestricted basis.
Implementation timeline
The G3W Implementation Plan (G3W-IP hereafter) is organized in a way that allows for step-wise implementation with the actions within the current financial period (2024-2027) focusing on the Pre-operational Phase (G3W-IPP). The G3W Initial Operational Phase (G3W-IOP) is foreseen in the next financial period (2028-2031), including the consolidation of the G3W systems configuration for the 2nd Global Stocktake(GST-2) from 2026 to 2028.
The evolution of G3W beyond 2032 is to support the Paris Agreement Enhanced Transparency Framework (ETF), which will provide progress assessments towards the climate neutrality goal and ambition. G3W will aim to provide actionable information assisting the countries in their Long-Term Low greenhouse gas Emission Development Strategies (LT-LEDS), which provide the long-term horizon for the Nationally Determined Contributions (NDCs).
This phase of the G3W development is labelled the Enhanced Operational Phase (G3W-EOP). It aims to integrate maturing technologies from satellite remote sensing, ground-based networks, conventional, and data-driven modelling approaches stemming from artificial intelligence, with the goal of reducing uncertainties and increasing the reliability of the GHG monitoring systems.
