Achim Steiner, the UN under-secretary-general and executive director of UNEP, and Chinese actress Li Bingbing attend the launch ceremony of an exhibition in Shanghai on Sunday, July 04, 2010. [Photo: CRIENGLISH.com/ Xu Leiying]

In the coming month, visitors to the Shanghai Expo will be able to visit an exhibition named "The Nature of Cities", which is aimed at promoting environmental protection and sustainable development of cities.

The United Nations Environment Programme (UNEP), the exhibition's organizer, launched the opening ceremony of the month-long event on Sunday afternoon at the UN Pavilion in the World Expo Park.

Achim Steiner, the UN under-secretary-general and executive director of UNEP, and Chinese actress Li Bingbing attended the ceremony.

During the ceremony, Steiner formally designated Li as the Goodwill Ambassador of UNEP, hoping Li could exert her influence and call on more people to protect our environment.

In addition to the designation of Goodwill Ambassador, a well-known sculpture named "Urgency from a Polar Region" has been moved to the UN Pavilion. The art work, which was made by Chinese sculptor Yuan Xikun in 2008, was previously displayed in front of UNEP headquarters in Nairobi, capital of Kenya.

The base of the sculpture is a warming earth beneath a leaning iceberg thawing from the heat. Two young cubs and their mother balance on top of the thawing iceberg, clinging for survival. The exhibition's organizers believe the sculpture's theme of global warming will help visitors realize the importance of environmental protection.