Global goal 15. Life on land. This encompasses deforestation poaching and sustainable ecosystems. There are many groups dedicated to achieving these goals. Including the SPCA P.E.T.A, W.W,F and the government of Canada. Each nonprofit group has a multitude  of opportunities to help  the environment by sending money and volunteering. Below is a link to the global goal site where it lists all of their sustainability goals connected to this topic.
 http://www.globalgoals.org/global-goals/life-on-land/