This specific page lists some environmental human rights issues. This could aid in topic ideas for further research, individually or in groups. This group- The People's Movement for Human Rights Education- includes many other human rights issues in their webpage (children, education, housing, poverty, women, etc.) worth checking out. Also the "related links" section lists many additional education, social action and UN conference links as well.
Human Rights Watch is an independent organization dedicated to defending and protecting human rights- worldwide. They have the latest world news on various human rights issues. You can do a search by topic or world region. This site can be used to initiate class discussions via web 2.0 (or not) or to aid in research topics. It's probably most applicable for intermediate and beyond; adults and mature teens alike.