EHAC originated at a meeting of environmental historians in spring 2019. That summer, many of our original members participated in the writing of or signed an amicus brief to the U.S. Supreme Court on the case Juliana v. US, which argued on behalf of young people the historical case for a constitutional right to a stable climate. Later that summer, we became a working group of the Environmental Data Governance Initiative, or EDGI, which documents, analyzes, and advocates for analyzes, and advocates foranalyzes federal environmental data, websites, institutions, and policy.

In the summer of 2022, EDGI decided to focus on data availability.  Since EHAC has wider, member-driven goals, we decided to step out on our own.  EHAC continues to be closely associated with EDGI.