Thomas Midgley Jr. was responsible for two of the most environmentally damaging inventions of the 20th century. An environmental historian said he “had more impact on the atmosphere than any other single organism in Earth’s history.”
Midgley, while working for General Motors, pioneered the addition of lead to fuel. Intended to prevent engine knocking, it put huge quantities of lead into the atmosphere. This practice has since been banned in most countries, but there is a theory that all that lead in the atmosphere actually caused the rise in crime rates in the 1980s (so, I guess, Midgley was also indirectly responsible for Robocop?).
Midgley apparently got lead poisoning himself, and was moved to the refrigeration division, where he was part of the team that developed freon. It went into fridges, and later was used in spray cans as a propellant. Freon was the very first CFC; so we can add ozone depletion and a “super” greenhouse gas to his roster.
Midgley’s inventions ended up killing him as well: disabled by polio, he set up a system of ropes and pulleys to move in and out of bed. At 51 years old, he got tangled up in the ropes and died.