UK environmental lawyer Polly Higgins urges expanding the Universal Declaration of Human Rights to all life forms. She proposes a Planetary Rights declaration, similar to Law of Nature developed in Bolivia and Ecuador. In this video from Klimaforum09 in Copenhagen, she is introduced by George Montbiot.
All life has a right to exist, to habitat, to diversity and integrity, and to restorative justice,
defensible at law, and supported by a Planet Trust. For more details see her site This is Ecocide, her Copenhagen slide presentation and her blog. Earth Trustee duties and legal implications are explained on Trees Have Rights Too, which she founded in 2008, as well as WISE (Women in Sustainability and the Environment). The Ecologist magazine named her "One of the Top Ten Visionaries to Save the Planet".
See also her article on Ecocide (Jan 2012), her biography in Wikipedia, the NEF animation video The Impossible Hamster, and Quaker discussion of Zero Growth and fall 2009 conference on Zero Growth Economy.