Flags of participating nations and international institutions inside the Expo Garden. [Photo/China Daily]

With Expo 2010 Shanghai just getting started, many other cities are already positioning themselves as contenders for future Expos

The Expo 2010 Shanghai finally opened on May 1, bringing to an end 10 years of bidding, planning and building. But somewhere out there, Expo 2020 is just beginning.

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Ten years ago, at Expo 2000 in Hanover, Germany, I had the privilege to attend my fifth World Expo, as well as visit my fifth China Pavilion. It isn't unusual for a nation's pavilion to promote its upcoming Expos, but it was the first time I'd ever seen a nation promote its bid for a future World Expo.

The year 2010 seemed, at the time, so far in the future, you couldn't imagine what it would be like. But here was Shanghai proclaiming its plans to bid for Expo 2010. This past week, it became a reality.

It didn't happen without a challenge, though. Five cities bid to host the Expo 2010. The other cities were Wroclaw, Poland; Yeosu, South Korea; Moscow; and Quertaro, Mexico. In the end, Shanghai won and brought China its first International Exposition.

Yeosu would go on to win the smaller Expo in 2012 and Milan will host the next registered Exposition in 2015. But after that, who knows?

Cities are starting to line up to bid for a recognized Exposition in 2017 or 2018 (tailor made for smaller cities and developing nations) and the big prize, Expo 2020, is also still out there waiting to be won.

North America hasn't played host to an Expo since Vancouver hosted Expo 1986. Right now, city leaders in Edmonton, Canada, are making plans to bid for Expo 2017 - which would celebrate Canada's 150th anniversary - with an environmental and energy theme, recognizing that city's role in energy production.

There's also been talk of Montreal, host of Expo 1967, bidding for Expo 2020. The United States hasn't played host to a World's Fair, as they are commonly known there, since the 1984 Louisiana World Exposition in New Orleans. Unfortunately, that Expo suffered from low turnout and financial problems, which partly explains why there hasn't been a US Expo since. However, people throughout the US are wondering, that after 36 years, 2020 will be the year that a World's Fair returns.

The question is which city? San Francisco, Houston, New York, Atlanta, Los Angeles and Minneapolis have all been mentioned as possible contenders.

After 34 years, Europe ended its Expo drought when Seville hosted Expo 1992. There has had three held on the Continent since then. Several smaller cities in Europe have expressed interest in hosting Expo 2017 or Expo 2018. Izmir in Turkey and Copenhagen may also try to bid for the larger Expo 2020

Some ask whether it is now time for South America or Africa to invite the world to an Expo. With Rio de Janiero becoming the first city in South America to host an Olympics, in 2016, the question is how soon either continent might host an Expo. Rio and Sao Paulo have both expressed interest in Expo 2020.

Brisbane, Australia, hosted Expo 1988 and some there have wonder if it is now time for it to host the world again in 2020.

In Asia, Astana, Kazakhstan, is considering bidding for 2017, and the Philippines and Thailand have looked towards 2020, so too the Chinese province of Guangdong. Dubai in the United Arab Emirates has also talked about bidding for either a 2020 Olympics or Expo 2020.

In the coming years, the bidding process for the smaller and larger Expos will start to heat up. And sooner than you think, there will be another winner.

The author is an American who has attended seven World Expos. He is the founder of ExpoMuseum.com and co-host of The World's Fair Podcast.