Climate change is linked to a variety of locally evident health effects. Local health systems and related services are struggling to deal with current impacts and will have to do much more in the future. Prominent topics identified by local health systems are heat-humidity stress, infectious disease, and linked food-water security. In many settings around the world, formal institutions such as governments and businesses may provide limited responses, especially for those most in need. Consequently, grassroots organisations are taking initiatives to try to translate available knowledge into action for themselves. Activities cover, for instance, environmental monitoring and participatory development to determine which climate change-related actions for mitigation and adaptation would be most suitable to support local health systems. Being non-profit, often informal, and with limited resources, these organisations face classic community collective action problems of incentivising members to create and manage systems outside formal institutions such as markets and governments. One formal system including and connecting climate change and health is the United Nations, within which several mechanisms for the 2030 agenda sit. The 2030 agenda's relevance for local action is not always clear, especially thinking beyond 2030 when considering the development and implementation of long-term, local, sustainable solutions in less affluent locations. Two case studies are examined here, both of which are isolated with severe resource constraints: Sitka, Alaska and Toco, Trindad and Tobago. Semi-structured interviews with local environmental groups presented their concerns and opportunities regarding climate change, health, and sustainability to and beyond 2030. Lessons emerged that typical ideas from sustainability such as “participatory processes” and “resilience” might not always be as meaningful for long-term local action as might be assumed from global knowledge. Ways forward for local health systems in the context of climate change are suggested based on the groups’ experiences and advice.