C-ROADS is a free, award-winning computer simulator that helps people understand the long-term climate impacts of national and regional greenhouse gas emission reductions at the global level. It is designed to broaden decision-maker understanding of the climate system’s responses to human intervention through rapid-cycle-time simulation. C-ROADS has helped the world to understand the impact of the emission reduction pledges countries have proposed to the United Nations. These proposals take different forms with different reference and target years, however, using C-ROADS we can rapidly test these policies to determine whether collectively they are enough to stabilize temperature below 2°C. C-ROADS World Climate is made available for free to make insights about what it takes to address climate change more accessible. We encourage you to use C-ROADS as part of a World Climate Simulation, where a group of people play the roles of UN climate negotiators working to create an agreement to limit global warming.