I read the High Country News routinely. It covers environmental issues for the western states. It has been around for years and the articles are well researched and written. A subscription is required to read the full issues, but most of the articles are available for free. http://www.hcn.org/

Also, Orion Magazine, which has a literary bent on living lightly on the planet. It is less scientific and more philosophic. Again a subscription is required, but they are very generous with free articles. One regular contributor is Derrick Jensen, who always offers up some interesting food for thought. http://www.orionmagazine.org/