Ship trails are clouds produced by ships at sea, polluting the atmosphere. A redirect to ship tracks would be easy enough to add to Wikipedia.
While one of the sources for the Ship tracks article is Twomey, S. (1977). "The Influence of Pollution on the Shortwave Albedo of Clouds". J. Atmos. Sci. 34 (7): 1149–1152.
You won't find "pollution" in the Wikipedia article.