David Peichel monitors his energy usage at his three-bedroom Minneapolis home with something called a kilowatt meter, which looks like a fancy outlet connector plug.
"You just unplug the toaster, plug the kilowatt meter into the wall, plug the toaster back into the kilowatt meter," says Peichel. "It tells you what the voltage is."
He started monitoring his energy usage about a year ago when he became worried about the rate at which climate is changing.
Peichel began by tracking his emissions since 2004, using old utility statements and online tools to calculate his transportation emissions. Then he turned to the kilowatt meter to monitor every one of his appliances.
"It's that dehumidifier that (was) killing us," Peichel says. He got rid of his dehumidifier and made other changes. His emissions have gone down by about 8 percent, and his utility bill is half as much as it used to be.
His goal -- zero emissions.
This is a mini-version of what 32 mayors in Minnesota have pledged to do. Cities include small ones like Milan with a population of 310, and big ones like Minneapolis and St. Paul.
Minneapolis was among the first 10 cities in the nation to sign the agreement. The cities committed to reduce greenhouse gas emissions below 1990 levels by 7 percent.
Their deadline is just four years away, and research shows emissions in Minnesota keep going up.
One of the first steps they're taking is just what David Peichel did -- creating an emissions inventory from sectors like energy, waste, and transportation.
"My frustration is that people spend so much time analyzing carbon emissions that they don't take action."
"I look at the greenhouse gas inventory this way -- when you're setting out to go somewhere, it generally makes it easier to get there if you know where you are starting from," says John Bailey, an energy analyst with the Minneapolis-based nonprofit Institute for Local Self-Reliance.
Bailey says the inventory by cities is critical.
"When it [the inventory] is done and if it's done correctly, the policy options, and the investment that cities can make, will just jump off the page," says Bailey.
But so far, getting the information has been challenging. Almost all of the cities are still in the planning stages of generating the inventory. St. Paul is the only Minnesota city with a current inventory.
Gayle Prest, the sustainability coordinator with the city of Minneapolis, says the city hasn't had an inventory since 1993. Part of the problem is that the software available has been difficult to work with.
"We are going to be re-doing it in 2008 -- our whole greenhouse gas emissions inventory," says Prest. "Technology has improved a lot, so it's getting easier to compare apples to apples among cities."
Cities also have to get their numbers from multiple sources, including utility companies like Xcel Energy and CenterPoint.
The city of Duluth had to go through at least 30 sources when it gathered its numbers back in 2001. Some cities say their inventories have been slowed because it's been difficult getting that information from utilities.
The data systems at Xcel aren't built to share information the way cities are requesting it, according to Karen Utt, a senior environmental analyst with Xcel.
"To make a goal that large and not have any idea of how hard it would be, and then have the expectation that someone is going to do it for them -- it just amazes me," Utt says.
Xcel was forced to adapt its data systems in Boulder, Colo. because the city passed a carbon tax. Now Boulder can easily download emissions information from Xcel on a monthly basis. Utt says Xcel is working to translate those capabilities throughout the whole company.
But critics say cities are making it too complicated for themselves.
"My frustration is that people spend so much time analyzing carbon emissions that they don't take action," says Sheldon Strom, executive director of the nonprofit Center for Energy and the Environment.
Cities should just focus on government operations, he says.
"When you look at the emissions from the residential sector or the business sector at the city level, you end up with approximations that are not that accurate anyhow," says Strom.
It's easy to calculate carbon savings after making some real changes, Strom says. He says cities could meet their targets if they focused on energy efficiency. He says it'll take millions of individuals making small changes, like Peichel, to make a real dent in reducing carbon emissions.
Over the next five years, cities, including those with little resources, will be able to rely on grant money from the 2007 Energy Bill. Congress blocked out $10 billion to help states and local governments "green" their cities.
This money could go towards things like hiring someone to figure out their carbon footprint or retrofitting old buildings.