The adjective climactic corresponds to the noun climax: "a climactic scene." The adjective climatic corresponds to the noun climate: "climatic research."
Examples:
- In the climactic chase, the fugitive runs through downtown Manhattan and up the steps of the courthouse.
- Most climatologists prefer to follow 1000-year cycles or longer when describing climatic changes in earth's history.
Practice:
(a) The House moved toward a _____ vote on legislation to remake the health care system.
(b) The true costs to society of global _____ changes are unknown.
