The crossword solution for the term 'prefix with climate' is ECO, which is a three-letter word. ECO is an abbreviation of the word 'ecology', which is the study of the relationship between organisms and their environment. ECO is often used as a prefix to words related to the environment, such as 'ECOSYSTEM' or 'ECOLOGICAL'. It is also used to refer to environmentalism, which is the practice of protecting the environment and its resources.