Here wee share very interesting video that relates to unintended consequences. In the social sciences, unintended consequences (sometimes unanticipated consequences or unforeseen consequences) are outcomes of a purposeful action that are not intended or foreseen.
Unintended consequences can be grouped into three types:
Unexpected benefit: A positive unexpected benefit (also referred to as luck, serendipity or a windfall).
Unexpected drawback: An unexpected detriment occurring in addition to the desired effect of the policy (e.g., while irrigation schemes provide people with water for agriculture, they can increase waterborne diseases that have devastating health effects, such as schistosomiasis).
Perverse result: A perverse effect contrary to what was originally intended (when an intended solution makes a problem worse).
There is also this article from the University of Birmingham that talks about unintended consequences regarding air quality projects.