Citizen science in hard-science calls (plant health, climate, health)

Citizen science, meaning research in which members of the public take part in producing knowledge, is not confined to social science calls in Horizon Europe. It is written into topics on plant pests, soil, climate adaptation and biodiversity, and it shows up in funded health projects. The wording decides whether it is a requirement or a choice.

What the Programme Guide says

The Horizon Europe Programme Guide (V5.1, 15 September 2025) lists, among open science practices, the involvement of citizens, civil society and end-users in co-creating research agendas and contents, and gives citizen science as the example. It is a recommended practice, not a mandatory one, unless a work programme topic or call conditions say otherwise.

Open science practices are evaluated under the Excellence criterion, in the methodology part, and under Quality and efficiency of implementation. This does not apply to the European Research Council. The guide describes citizens as possible sources of ideas, knowledge or data, as data collectors or analysers, and as testers.

Three strengths of wording

Topic	Field	What the topic text says	Funded example on CORDIS
HORIZON-CL6-2023-GOVERNANCE-01-16 (deadline 23 March 2023)	Plant health	Required activity: integrate citizen science as a tool to monitor pests and develop robust methods to use its data.	CERBERUS (2024-2027, coordinated in Spain) combines satellite data, insect traps and robots with citizen data from dedicated apps, and has a citizen science specialist in the consortium.
HORIZON-MISS-2022-SOIL-01-09 (deadline 27 September 2022)	Soil health	Whole topic: run citizen science initiatives, ideally in all Member States, covering at least soil biodiversity and soil pollution, and test quality control methods for the data.	ECHO (2023-2027, coordinated in Italy) plans 28 initiatives and 16500 assessed sites, with an open repository called ECHOREPO.
HORIZON-MISS-2024-CLIMA-01-03 (deadline 18 September 2024)	Climate resilience indicators	Expected: complement data collection with citizen science and find ways to engage citizens, in particular vulnerable groups.	UNDERPIN (2025-2028, coordinated in France) lists citizen science next to Earth observation data in its monitoring framework.
HORIZON-CL6-2024-BIODIV-01-1 (deadline 22 February 2024)	Invasive alien species	Optional: participatory approaches such as citizen science "could be appropriate".

The optional wording continues in the 2026-2027 work programme. Topic HORIZON-CL6-2027-01-BIODIV-04, on living labs for invasive alien species (deadline 22 September 2027), says a citizen science approach could be appropriate to produce, collect and analyse data. The same topic requires an effective contribution of social sciences and humanities.

Health

In Cluster 1 (Health), citizen science was found in project descriptions more than in topic titles. Two projects under the environment and health destination state it in their CORDIS objectives:

TULIP (2024-2028, coordinated by Heidelberg University Hospital, topic HORIZON-HLTH-2023-ENVHLTH-02-01) studies antimicrobial resistance, plastic pollution and climate change in aquatic environments and engages communities and citizen scientists in research and co-design.
InChildHealth (2022-2026, coordinated by Aalto University, topic HORIZON-HLTH-2021-ENVHLTH-02-02) studies indoor air quality in schools and develops guidelines and training material partly with children in a citizen science approach.

What the topic texts expect from the method

The soil topic is explicit about the scientific difficulty: integrating citizen data with professional observations raises issues of quality control, methodology and observer bias. It asks for protocols, field guides, quality control methods and a long-term data repository. In these calls citizen science is a data collection method that has to meet scientific standards, with public engagement as a second aim.

How to use this when reading a topic

Search the topic text for "citizen". The Funding and Tenders Portal full-text search also finds topics where the term appears only in the description.
Read the verb. "Integrate" or "run" in the scope makes it part of what is evaluated. "Could be appropriate" leaves the choice to you, and the proposal should then say why it is or is not used.
Describe it in the open science part of the methodology, with the protocol, the data validation step and the task that uses the data.