IIASA is dedicated to making science accessible to everyone. Open science helps to amplify the positive scientific and societal impacts of research while also increasing the visibility of the institute and its researchers.

IIASA introduced an open access policy for publications in 2016, and has also made several models openly accessible, such as the Community Water Model (CWatM), which is used to assess water demand and supply at different spatial and temporal scales, and the Model for Energy Supply Strategy Alternatives and their General Environmental Impacts (MESSAGE). This practice has proved beneficial, as the external research groups that use IIASA models often adapt and improve them, amplifying their impact. For example, the MESSAGE model was adopted by COPPE, the Federal University of Rio de Janeiro, about 20 years ago and has been influencing energy planning and climate change mitigation policy decisions in Brazil ever since.

Building on the success of these open-access models, in 2021, IIASA made increased efforts to make raw data and additional models publicly available. The IIASA Biodiversity and Natural Resources Program (BNR) made the Global Hydro-economic Model (ECHO), a tool to inform the design of cost-effective and sustainable water policy decisions, and the Integrated Species Distribution Modeling tool for working with biodiversity data, publicly available. The Novel Data Ecosystems for Sustainability Research Group (NODES) in the IIASA Advancing Systems Analysis Program (ASA) also made numerous datasets resulting from its open Geo-Wiki Platform publicly available, to foster progress towards the UN Sustainable Development Goals.

To contribute to studying and curbing the impacts of the pandemic, the COVID-19 European regional tracker developed by ASA researchers in 2021 has also been made freely accessible. The tracker presents data on daily COVID-19 cases at the district or sub-district level for 26 European countries from January 2020 until the present, and the raw data, the code, and the final homogenized files are all provided in an online repository, which is updated on a monthly basis.

Apart from making models openly accessible, IIASA aims to support the researchers who wish to use and build upon them. The Energy, Climate, and Environment Program (ECE) launched a website to share learning material from various activities by ECE researchers, including lectures, workshops, and tutorials. The website helps self-directed learners to learn how to use open-source modeling tools and adopt better practices of collaborative research and open science.

ECE researchers have also been instrumental in improving the transparency and reproducibility of recent reports by the Intergovernmental Panel on Climate Change (IPCC) reports. Building on work for the IPCC’s Special Report on Global Warming of 1.5 °C (SR1.5), scripts to generate figures from the Summary for Policymakers of the Sixth Assessment Report (AR6) Working Group 1 were released on GitHub and the data supporting many quantitative, scenario-based statements was made available via the AR6 Scenario Explorer hosted by IIASA. These resources can serve as an important template for future efforts to advance transparency and reproducibility and will hopefully continue to influence open science in the future.