A greenhouse gas emissions target refers to the emission reduction levels that states set out to achieve by a specified time. For example, a state may set a target of reducing emissions to 1990 levels by 2020, and to 50 percent below 1990 levels by 2050.
States use a variety of baseline years, ranging from 1990 to 2006, and a few different years for the ultimate target, ranging from 2020 to 2050. Most states have an common ultimate target year of 2050. The baseline year and additional details can be found by clicking on individual states.