MINNEAPOLIS (WCCO) — Critics of the proposed Southwest Light Rail line are trying something new in their attempts to stop the project.

On Saturday they tied green ribbons on trees that they say would be taken out to make way for the tracks along the Kenilworth Corridor in Minneapolis. They argue cutting down the trees will damage air quality because they help absorb carbon dioxide.

The light rail extension would operate from downtown Minneapolis to St. Louis Park, Hopkins, Minnetonka and Eden Prairie. Metro Transit says it’s needed to ease traffic congestion in that region.