1997 Earth Summit
UN Offices in Vienna
Three souvenir sheets were issued to commemorate the fifth anniversary of the United Nations Conference on Environment and Development, commonly known as the Earth Summit, and the special session of the General Assembly to review Agenda 21, an environmental plan stemming from the conference.
A fourth sheet was created with an overprint commemorating Pacific 97, the major, once-a-decade philatelic show in the United States. Only the U.S. denominated sheet was overprinted.