Climate Data Gaps Leave Communities Searching for Clear Answers to Growing Local Risks

The first assessment, D2.1, examines the observation networks and data centres supporting measurements collected directly from the environment.

A city planning for dangerous heat needs to know which neighbourhoods face the greatest exposure, and people protecting mangroves need information that reflects conditions along their own coastline. The world produces unprecedented amounts of climate data, but three new iClimateAction assessments describe an uneven and insufficient observing system that does not always give decision-makers the practical answers they need. The findings point to gaps in monitoring, uncertain funding and difficulties turning scientific measurements into information people can use to prepare for drought, rising seas and increasingly frequent and intense climate extremes.

The assessments bring together work by the Global Climate Observing System (GCOS), the World Meteorological Organization (WMO) and the Group on Earth Observations (GEO). They examine instruments operating on land, at sea and in the atmosphere, the use of satellite observations, and the experiences of people applying climate information. These systems track the 55 Essential Climate Variables identified by GCOS as critical to understanding climate change, making their reliability a practical concern for communities facing difficult planning decisions.

The Missing Measurements Behind the Global Picture

The first assessment, D2.1, examines the observation networks and data centres supporting measurements collected directly from the environment. Many networks depend on short-term research projects, voluntary support or contributions of equipment, services and staff time, particularly across ocean and land monitoring. Geographical gaps remain across Africa, South America, Southeast Asia, the Southern Ocean, polar regions and other remote areas, leaving the global picture incomplete.

Direct measurements are essential for checking and calibrating satellite observations and recording conditions that instruments in orbit cannot adequately capture, including changes beneath the ocean surface and inside complex vegetation canopies. The report identifies problems with governance and long-term sustainability, highlighting European Research Infrastructure Consortia, known as ERICs, as one possible model for shared investment, lasting oversight and open access to infrastructure and data. D2.1 and the satellite assessment, D2.2, will contribute to the forthcoming 2027 GCOS Status Report, which evaluates monitoring progress and identifies critical gaps or deterioration in observing networks.

Satellite Coverage Does Not Guarantee Usable Information

Satellites contribute observations to 42 of the 55 Essential Climate Variables, offering repeated and near-global coverage for much of the climate system. The D2.2 assessment shows that the usefulness of this coverage depends on much more than the quality of the measurements. In a February 2026 survey of 33 climate experts, communication with decision-makers was the most frequently selected barrier to greater use of satellite observations, ranking ahead of data accessibility and observation quality.

Problems extend across the journey from collecting measurements to applying them, including limited processing capacity, difficulties making different datasets and systems work together, and gaps in the direct observations needed to support satellite information. Data may lack the geographical detail or frequency required for a particular decision, making an otherwise valuable dataset less useful to someone working on a specific local problem.

Local Decisions Need a Closer View

The interim D2.3 assessment draws on iClimateAction's Urban Heat and Nature/Ecosystems demonstration activities to examine users' needs. Urban heat practitioners often require information at neighbourhood or street level, where global observations may not provide enough detail. In the Maldives, global datasets can support an initial assessment of risks to mangroves and other ecosystems, with local decisions still requiring detailed field measurements and information specific to the ecosystem involved.

The reports call for sustained investment in observation networks, closer integration of satellite and ground measurements, better data management and stronger collaboration between providers and users. Their central concern is the often-neglected final step: turning reliable observations into understandable, trustworthy information that supports action. iClimateAction, a Horizon Europe project connecting GEO, WMO and GCOS, works to strengthen that chain from climate science to services, helping the information reach the people who need to act on it.