The roadmap is organized into activities that take place at three levels, that is, global, national and local, with interactions between these levels to reach a set of overarching goals (Fig. 4). At the global level, the goal is to integrate citizen science into the formal SDG reporting process. As outlined in Box 1, the SDG goals, targets and indicators have been developed by the IAEG-SDGs, in consultation with experts from the UN, civil society, businesses, academia and NSOs. This development process is still ongoing, whereby Tier III indicators are moved to Tier II and eventually Tier I, with annual reporting to the High-level Political Forum for Sustainable Development. Each indicator is the responsibility of one or more custodian agencies, which work with experts to develop indicator methodologies. Pilot projects are then run in designated countries to demonstrate the methodology and the data collection.

Fig. 4: Roadmap of activities for integrating citizen science into SDG reporting. Upper box, global activities. Lower box, national activities. Full size image

To be part of this global reporting process, Tier II and III indicators must be identified to which citizen science could contribute. Here we take the example of floating marine debris. As outlined above, we have already identified many initiatives that are involved in marine debris identification and clean-up, providing both temporal and spatial scalability, a high level of citizen participation and project longevity. The second step is to get the custodian agencies for the indicators identified on board. In the case of marine debris, the custodian agency is UN Environment, who are currently investigating the use of citizen science for this indicator. Workshops then need to be held whereby representatives from various citizen-science projects are brought together with UN Environment and experts in marine-debris science, to agree on a consistent set of protocols for measuring and collecting the data for SDG reporting. Clear guidance and usable tools need to be offered to citizen-science projects to make their data available and fit-for-use within the SDG framework. Countries with strong national citizen-science initiatives could then act as pilots for this indicator (for example, Australia, Chile, Ireland and the United Kingdom). If successful, these efforts could be scaled up to other countries. In this way, data from citizen science could be formally brought into the SDG reporting process at the global level.

The second level of the roadmap concerns activities geared at the national level (Fig. 4), particularly as responsibility for the SDG reporting process lies with national governments48. Here the overall goal is to build an environment of trust for the use of citizen-science data by national agencies. Organizations such as the Citizen Science Global Partnership, citizen-science associations and their working groups, and current Communities of Practice (CoPs) in citizen science should work actively with NSOs to bring citizen science into the scope of official statistics. A number of activities can take place in parallel, some of which have already been initiated. For example, the CoP on citizen science and SDGs, running within the EU-funded WeObserve project (https://www.weobserve.eu/), is currently mapping existing contributions of citizen science to SDG indicators and is identifying those indicators where projects could potentially contribute in the future. This mapping can help inform activities taking place at the global level.

Another activity is to compile an inventory of examples of good practice in the use of citizen science at the national level. The acceptance of data collected by citizens in the Philippines as outlined above is a prime example33 while Australia has developed its own ‘Method for Australia’s SDG baseline assessment’ that allows for the reporting and monitoring of quantities adapted to their specific country context49. For many of these ‘proxy’ indicators, citizen participation provides the main data collection mechanism. Aligning citizen science with the priorities of decision makers at the national level in this way will increase the likelihood of its adoption in SDG monitoring and reporting in other countries. Based on this inventory, we should seek to replicate models of good practice already taking place nationally.

A third activity is to build on existing policy frameworks that advocate citizen science for decision making (for example, the 2015 US White House Memorandum on Citizen Science; the US Crowdsourcing and Citizen Science Act, which was incorporated into Section 402 of the American Innovation and Competitiveness Act; the European Open Science Policy Agenda; the recommendations of the European Open Science Policy Platform; action 8 of the EU roadmap to streamline environmental reporting50; and the Ministerial declaration at the UN Environment Assembly at its fourth session51, which calls for the wider use of data from citizen science). Here the citizen-science community should work with decision makers in other countries around the world to craft policies that authorize, encourage and provide guidelines for the appropriate use of citizen science for SDG monitoring.

A fourth key activity in the roadmap will be to promote dialogue on data quality, which will be the number one concern for NSOs, as well as data management including standards, metadata and interoperability. The citizen-science community should work with statistical agencies and the scientific community to develop an agreed set of accepted protocols and minimum data quality standards required from citizen-science projects, drawing on a large body of research that already addresses quality issues and involving relevant working groups such as the CSA Data and Metadata Working Group. Moreover, opportunities should be created for peer-to-peer networking among statisticians to share lessons learned and best practices in using citizen science for SDG monitoring, including harmonizing data from citizen science with more traditional sources of data. These activities need to be paralleled by efforts to raise awareness of the current data quality-assurance mechanisms so that perceptions (and not just procedures) change that may otherwise stand in the way of using data from citizen science for the SDGs. At the same time, these best practices should feed into the activities taking place at the global and local levels.

In addition to data quality, interoperability is paramount to interpreting, sharing and integrating the data across different citizen-science initiatives, and with traditional and non-traditional data sources (for example, satellite imagery). The citizen-science community, in collaboration with SciStarter.org and other partner organizations, have been developing a new data and metadata standard for Public Participation in Scientific Research (PPSR), adapted from the Darwin Core standard for biodiversity52. Aligning PPSR core standards with the SDG indicators can reveal where citizen science has the potential to contribute the most, maximizing the efficiency of data infrastructure, storage and curation. Future iterations of the PPSR core standard can incorporate economic, environmental and societal dimensions of the SDGs. Cloud computing, artificial intelligence and other frontier technologies are also making this integration possible. The ultimate activity at the national level will be to work with NSOs to integrate data from citizen science in their statistical reporting.

The third and final level of the roadmap concerns activities that affect citizen-science projects operating at the local level. The citizen-science community must actively support citizen-science projects through guidance and tools that will help them adhere to the FAIR data principles, while promoting the sharing and reuse of the data. Best practices developed at the national level should feed down to the local level. At the same time, the citizen-science community must identify potential privacy risks and help citizen-science projects adhere to applicable data privacy laws, for example, the EU General Data Protection Regulation effective from 25 May 2018, which requires protection of personal data and addresses the transfer of data out of the EU; this has implications for global-scale citizen-science projects. The US White House Office of Science and Technology Policy memorandum on citizen science, issued 30 September 2015, provides guiding principles, including providing volunteers with appropriate access to their data, ensuring meaningful engagement of the public in scientific research, and giving appropriate attribution for volunteer contributions. In addition, the European Citizen Science Association has developed a set of 10 principles for citizen science that should be followed53. Finally, the citizen-science community should raise awareness of the SDGs among citizen-science projects, encouraging them to align their goals to SDG monitoring where relevant.