ECVs are physical, chemical, or biological variables that provide the necessary empirical evidence to understand how our climate is evolving. This information is critical for informed decision making in climate change mitigation and adaptation. The ECVs help assess future risk scenarios, enable the attribution of (extreme) climate events to underlying causes, and form the basis of effective climate services.
GCOS specifies 54 ECVs that are identified based on three criteria (GCOS, 2016):
- Relevance: The variable is critical for characterizing the climate system and its changes.
- Feasibility: Observing or deriving the variable on a global scale is technically feasible using proven, scientifically understood methods.
- Cost effectiveness: Generating and archiving data on the variable is affordable, mainly relying on coordinated observing systems using proven technology, taking advantage where possible of historical datasets.
observations from land-based and airborne in-situ and remote sensing platforms, in addition to satellites. However, satellites can significantly contribute to many ECVs, making Earth observation (EO) a key component of climate monitoring.
There are many international initiatives that attempt to deliver climate information to the decision makers. The Copernicus Climate Change Service (C3S) will soon deliver operational data and climate information services for a range of domains and sectoral areas. The C3S portfolio is currently under development and its dataset provision is designed to be extensible in the future. Under C3S the ECVs will be provided through climate projections, reanalysis, satellite observations and seasonal forecasts.
At the European Space Agency (ESA), the Climate Change Initiative has the objective to realize the full potential of the longterm global EO archives that ESA together with its Member States have established over the last thirty years, as a significant and timely contribution to the ECV databases required by the UNFCCC and IPCC. Existing ECV datasets are currently being extended and datasets for new ECVs are planned for the future.
The Earth Observation for Sustainable Development (EO4SD) Climate Resilience cluster will tap into the dedicated ECV projects C3S and ESA CCI and provide customized information including baseline analysis to support multilateral development investment projects and their climate resilience.