Al Gore was racking his brains on Friday to express his excitement during his three-hour visit to the Shanghai Expo.

In the China pavilion there is a greenhouse in which lotus blossom.

"The design of this greenhouse has sent a message that China expects sustainable and peaceful development," Curator Qian Zhiguang explained to Gore.

The 62-year-old former US Vice-president listened to his explanation with a rare smile.

On Friday morning, Gore was also moved by a special gift - a low-carbon commuting card, which was developed by the Shanghai Expo Bureau, Shanghai Environment Protection Bureau and the US-based Environmental Defense Fund to remind expo visitors to take public transportation and reduce their carbon footprint.

All the proceeds from the cards are being used to help poor farmers in the earthquake zone of Sichuan improve their ability to cope with changing climate conditions.

"I hope all the visitors have this (commuting) card, " Gore said.

After the tour, Gore said: "I am humbled to say that if I need to give tips to Chinese people, my No. 1 tip would be - come and visit Shanghai Expo."

"They will have all the green life tips they need," Gore added.