Climate change is a major threat to the world's protected areas, yet the difficulty of making good predictions of the impacts of change constrains management, planning, and policy making. An important factor limiting development of these predictions is the inability of existing computer models, which simulate ecosystem and related processes, to easily exchange information. The ecological Model Web, now in the early stages of development, addresses this limitation. The Model Web will be an open-ended network of interoperable computer models and databases that use web services to communicate with one another and with end-users. Analogous to the World Wide Web, it will grow organically and opportunistically within a framework of broad goals and high-level standards. Making it easier for models to communicate will increase their collective power and the breadth of questions they can address, while providing web access to their results will facilitate greater extraction of societal benefits by managers, policy makers, and the public.