The power of meetings will be on full display in Pittsburgh this September when leaders from the world’s 20 largest countries convene for the G20 Summit, seeking solutions to stimulate the global economy. The G20 usually meets annually, but shortly after the G20 met in London last April, President Barack Obama offered to host a second summit this year, given the state of the global economy.

When the Pittsburgh G20 convenes September 24-25 at the David L. Lawrence Convention Center, it will have had less than four months to plan. A daunting task for a meeting that will be attended by some 1,600 delegates, including heads of state; 3,000 members of the media; and 4,000 security personnel.

The White House, along with the U.S. State Department, took the lead in organizing the meeting. (The host country typically plans the event.) In May, the State Department put out a request for proposal seeking host cities, and Pittsburgh was picked.

Why Pittsburgh? “They thought it delivered a couple of messages that the president wanted to connect,” says Joe McGrath, president and chief executive officer at Visit Pittsburgh. One is that Pittsburgh represents the idea of reinventing oneself and prospering after a staggering economic blow. Pittsburgh lived that experience in the 1980s after the steel mills closed and it successfully rebuilt its economy around the technology sector. The second message is a commitment to the environment. Pittsburgh has been at the forefront of the green movement, with the country’s first Leadership in Energy and Environmental Design–certified convention center.

Next, the State Department hired general service contractor Hargrove Inc., Lanham, Md., to plan the event. (Halethorpe, Md.–based Showcall will handle the audiovisual and technical requirements.) Hargrove is no stranger to high-profile events, having handled a previous G20 and G8 meeting, Pope Benedict XVI’s Mass in Washington, and several presidential inaugurations, including the Obama inauguration, where it planned 53 events in 35 venues over a three-day period.

The G20 Summit in Pittsburgh won’t be as logistically complex as the inauguration, but it will be challenging to pull together an event of this scale in such a short period of time, says Hargrove CEO Tim McGill.

Most of the activity will be confined to the convention center, says McGill. The main plenary session will seat 40 or 50 leaders at a large table. Meeting rooms will be set up for each of the participating countries, and beyond that, there will be lounges, food and beverage, and perhaps the largest pressroom McGill has ever seen. The Secret Service, the FBI, and the National Security Council will provide security. However, heads of state from the G20 countries will also travel with their own security entourages. Overall, close to 4,000 security personnel are expected in Pittsburgh.

Additionally, Hargrove will use environmentally friendly materials and work with the convention center staff to recycle a large percentage of waste. “This administration has made it very clear, from the inauguration onward, how important it is that the green initiative is in the front and foremost of everything we do,” says McGill.

The CVB has been busy hosting site visits by White House staffers and State Department officials, as well as overseas delegations. “Each of the countries has its own delegation coming to look at hotel rooms and other facilities,” says McGrath. That’s because each G20 nation is responsible for booking its own room blocks, which they are doing through the CVB and its partner, Passkey. “Our responsibility as a bureau is housing, assistance with venues, and providing information about the city,” he says.

The summit is expected to have an economic impact of at least $8 million to $10 million. The city expects to enlist the help of about 1,700 volunteers during G20 week.