For the Earth Day 2013 [slide show]

Anna Mandeita, Untitled, 1978.

Keith Arnatt, Liverpool Beach Burial, 1968. Gelatin-silver print, Courtesy of the Keith Arnatt Estate; Maureen Paley, London.

Richard Long, A Line in Scotland, 1981. Courtesy the artist

Thiago Rocha Pitta, Herança, 2007. Video stil. Courtesy the artist.

Thiago Rocha Pitta, Naufrágio interior, 2009. Video stiill. Courtesy the artist.

Chris Engman Inverse negative, 2010. Archival inkjet print. Courtesy the artist.

Michael Cataldi, Prop, 2007. Steel, wood, fabric, dirt and turf. Courtesy the artist.

Charles Stankievech, Loveland, 2011. video still. Courtesy the artist.

Richard Serra, Shift, 1970. King City, Ontario, Canada.

Robert Smithson, Spiral Jetty, 1970. at Rozel Point, Great Salt Lake, Utah.

Christo and Jeanne-Claude's "Wrapped Coast", one million square feet, Little Bay, Sydney, Australia, 1968-69. Photo by Harry Shunk, © 1969 Christo