. >> reporter: a report by climate justice organization 350.org and a physicist at macalester college in minnesota found the line 3 expansion would increase the state's existing annual greenhouse gas emissions. >> we don'teed any more oil pipelines. you know, it's the end of the party. who wants to be holding the last fossil fuels pipeline? >> reporter: in its latest effort to stop line 3, last december, honor the earth joined the white earth and red lake nations, and the sierra club, in filing a federal lawsuit against the u.s. army corps of engineers. the lawsuit argues that the army corps didn't adequately assess the potential for exacerbating climate ange when it approved the permit, nor its impacts on indigenous treaty land rights. tara houska is couchiching first nation anishinaabe and the founder of the indigenous-led giniw collective. >> treaties are in the u.s. constitution as the supreme law of the land. you know, it's time to honor the treaties in a different way. >> reporter: she says the replacement pipeline opens up new areas of the state to potential spills that could p