If a team hasn’t been formed yet for that SDG, yes. If a team has been formed and is most of the way through writing the book, it would be disruptive to have someone join who isn’t up to speed. In between those two extremes, there is a maybe which depends on the need of the team, where they are in their research and writing, and your interests and skills. Please check the specific SDG’s page to check for openings.
