Designing for impact: How interactive climate simulations foster learning, engagement and action

Policy design in climate and sustainability is hindered by nonlinear feedbacks, long delays, and uncertainty that limit the effectiveness of traditional information‑centric communication. The manuscript examines how simulation models can be designed and deployed to support learning and decision‑making by integrating analytical rigor, model transparency, and structured stakeholder engagement. Using the C‑ROADS and En‑ROADS climate policy simulators and insights from the MIT Climate Pathways Project (CPP), the paper distills three design principles for impactful simulation‑based learning environments:

• (1) rigorous, empirically grounded modeling with comprehensive simulator transparency;
• (2) user‑centered interface design that scaffolds discovery while preserving access to underlying structure and assumptions; and
• (3) facilitated, interactive engagements that enable participants to test mental models through experimentation and social learning.

First, rigorous modeling emphasizes the necessity of formal testing and documentation to build confidence in policy insights. En‑ROADS and C‑ROADS are developed iteratively, grounded in the scientific literature, are calibrated to historic data, and their future behavior is tested against the climate scenarios in the Network for Greening the Financial System (NGFS) and other widely-used Integrated Assessment Models (IAMs), GCAM, MESSAGE-GLOBIUM, and REMIND-MAgPIE. Multi‑layered documentation—including an online technical reference guide, simulator behavior comparisons, and easily accessible explanations—enables scrutiny of model mechanisms, parameters, and simulator behavior. Users can interrogate and vary assumptions to explore robustness and uncertainty.

Second, user-centered interface design concerns design for “guided discovery.” The simulator’s layered interface presents key outcomes and policy levers in an intuitive top layer while offering advanced controls (≈250 parameters) and extensive visualization (≈180 graphs). Real‑time, browser‑based computation supports rapid scenario exploration across devices and languages, enabling both individual and group use cases. Iterative usability testing ensures that the interface reduces cognitive load while preserving analytical depth.

Third, facilitated, interactive engagements include the design of engagement protocols that combine analytic reasoning with experiential, collaborative learning. We highlight three formats:

• the World Climate Simulation with C‑ROADS;
• the Climate Action Simulation with En‑ROADS; and
• the En‑ROADS Climate Workshop for policy briefings.

These interactive engagements prompt participants to articulate expectations before running scenarios, confront divergences between expectations and simulated outcomes, and engage in structured discussion and reflection. Such practices surface misconceptions about leverage points (e.g., relative effects of pricing emissions, efficiency improvements, carbon dioxide removal, afforestation, or bioenergy), foster systems thinking, and support informed action.

The CPP and the broader community infrastructure amplify reach and consistency. As of December 2025, more than 472,000 participants in 183 countries—including over 23,000 leaders in government, business, and civil society—have engaged with the simulators. A global network of En‑ROADS Climate Ambassadors (over 940 in 90+ countries) has collectively engaged upwards of 354,000 people through a structured training and certification program, extending the implementation of the design principles in diverse contexts.

The paper concludes with a conceptual model for future empirical research that hypothesizes how model rigor and transparency and interface usability affect learning and action via the mediating mechanism of facilitated, interactive simulation‑based experience. This framework supports systematic evaluation of simulator design and engagement quality, informing the development of SD‑based tools and protocols that can strengthen climate literacy, improve policy reasoning, and support evidence‑based action.