In the 1990s, Hertsgaard's attention turned to the ecology of the Earth.
Some of the notable books published after 1972 include the State of the World reports issued by the Worldwatch Institute (produced annually since 1984); the influential Our Common Future, published by the UN’s World Commission on Environment and Development (1987); Earth in the Balance, written by then-US senator Al Gore (1992); and Earth Odyssey (ISBN 978-0767900591) by journalist Mark Hertsgaard (1999).
Mark Twain | Mark | Mark Wahlberg | Mark Knopfler | Mark Zuckerberg | Mark Rothko | Mark Antony | Mark the Evangelist | Gospel of Mark | Mark Ronson | Mark Spitz | Mark Foley | Mark Murphy (singer) | Mark Murphy | Mark McGwire | Mark Hamill | Deutsche Mark | Mark Taper Forum | Mark Millar | Mark Lewisohn | Mark Kermode | Mark Lanegan | Mark Waugh | Mark Rydell | Mark Goodson | Mark Owen | Mark Mothersbaugh | Mark Medoff | Mark Heard | Mark Dayton |