Climate change is a human rights issue. Human rights philanthropy can address climate change and other human rights challenges by supporting grassroots organizations led by those most affected. However, traditional philanthropic practices often perpetuate harmful power dynamics and do not reflect the needs of the communities they serve. An ecosystemic approach to human rights philanthropy can help by shifting power to grassroots organizations, supporting collaboration and co-learning. Global Greengrants has developed an ecosystemic approach that views the entire system of actors and organizations working for environmental justice as interconnected and interdependent rather than competitive. This is a values-led approach to workplace organizing that prioritizes equity, power sharing, and collaboration. Participatory grantmaking is an example of an ecosystemic approach to human rights philanthropy in which the communities impacted by funding decisions make decisions about grants. The fund’s grantmaking process is led by a network of activist advisors who represent communities that experience environmental injustices and human rights violations. An ecosystemic approach to human rights philanthropy is essential to address climate change and Global Greengrants Fund is an example of how participatory grantmaking can work efficiently and at scale, with a decentralized decision-making model that involves a network of activist advisors who decide on the allocation of resources.