How many people does it take to change a compact fluorescent lightbulb?

Two. And their names are Brendan Daley and Joseph Shacter.

Or 2.8 million, if Daley and Shacter have their way.

Daley is deputy commissioner of Chicago's Department of Environment and Shacter is senior policy advocate for the Environmental Law Policy Center.

Together they are trying to get Chicagoans to try the spiral-shaped energy-efficient bulbs.

They made their pitch for change -- handing out free bulbs earlier this month at an environmental event.

The free stash aside, Daley and Shacter spoke about the effects they believe global warming is having on the Midwest and the moves Chicago has made to curb them. The temperature has increased by at least one degree worldwide over the last century, Shacter said.

According to the Environmental Law Policy Center, Illinois, Indiana, Michigan, Minnesota, Ohio and Wisconsin are responsible for 20 percent of the carbon dioxide pollution in the U.S. and 5 percent of this pollution in the world.

These statistics are largely due to the Midwest being home to many coal mines, he said, adding that coal and automobile emissions combined make up about 44 percent of Illinois' total emissions.

"You do coal and then you add in that we're the hub of our nation's transportation network," he said.

The consequences of global warming, Shacter said, are serious.

Land area has started disappearing across the world in places like Indonesia and Alaska, he added, and coastal cities could face periodic flooding.

But this global issue presents the Midwest with a challenge, he said.

"In all of this, we believe very strongly that in our region, our city, that this whole phenomenon really presents us with an opportunity," he said. "Let's start talking about that."

The city of Chicago has already taken significant steps toward a greener future.

Since taking office in 1989, Mayor Richard M. Daley has planted nearly half a million trees in the city, Brendan Daley said.

"It's a very simple change we made in policy as a city," he added. "But it has a great impact on not only the global-warming side of things but the air-quality side of things."

A rooftop garden on City Hall and the creation of the Center for Green Technology are two more of the city's green accomplishments.

Close to 3 million square feet of green rooftop has been constructed in the Windy City after the rooftop at City Hall was built, Daley said.

Chicago also implemented an expedited permit process for those who choose to construct green buildings and distributed solar thermal grants to encourage the use of this alternative energy source.

The Second City touts one of the most extensive bike path systems in the country and is switching over to LED traffic signals.

Other plans are on the horizon for Chicago.

The city pledges to give away half a million compact fluorescent lightbulbs to residents this year, as well as providing people with the tools necessary to weatherize their homes, Daley said.

"We as a city are doing a lot around sustainability and green," he added.

According to a poll last year, about 85 percent of Americans believe global warming is occurring.

"What is refreshing now is that instead of debating over whether global warming is occurring or not, we're talking about what to do about it," Shacter said. "That is a healthy debate."

To the increasingly smaller group of Americans who don't believe in global warming, Shacter said they need to look at the science.

"There's no point in debating it anymore," he said. "Debate's over. It's over. The facts are what they are and the fact that a group of thousands of thousands of scientists from around the world have come to a conclusion that it's now 90 percent likelihood that it's human activity, it's done. It's done. Let's talk about what to do about it."

Daley agreed.

"I think oftentimes people think about global warming as something that's over there, ya know," he said. "It's over in Indonesia or in Asia or Africa or whatever and it's not. It's happening here."