Josh Fox, who wrote and directed the documentary feature film Gasland, which focuses on communities in the United States impacted by natural gas drilling.
Michael Pollan, who has written bestselling books about the interaction of nature and society.
Alice Walker, most famous for her book The Color Purple, who travelled to Gaza last year to oppose the Israeli blockade and wrote about her experiences.
Barbara Kowalcyk, who has campaigned for food safety.
After the award ceremony she will light the Imagine Peace Tower illuminated memorial, which is located on an island close to Icelandic capital Reykjavik.