Original sentence: On October 19, 2006, Ambrose introduced a Clean Air Act that purported to reduce the level of greenhouse emissions starting in 2020, cutting them to about half of the 2003 levels by 2050
Edited sentence: On October 19, 2006, Ambrose introduced a Clean Air Act that would significantly reduce the level of greenhouse emissions starting in 2020, cutting them to about half of the 2003 levels by 2050