Original sentence: Scientist William Connelley called "clearly false" Singer's assertion that there is controversy over whether "CFCs with lifetimes of decades and longer become well-mixed in the atmosphere, percolate into the stratosphere, and there release chlorine
Edited sentence: " is controversial.SEPP (or Fred Singer) has also commented on the question of Ozone depletion, making the clearly false assertion that the statement "CFCs with lifetimes of decades and longer become well-mixed in the atmosphere, percolate into the stratosphere, and there release chlorine