A new interactive website will allow citizens of 20 Minnesota cities to track how their communities are reducing greenhouse gas emissions — and how they are not.

The Regional Indicators Initiative (RII) site, a vivid and easy-to-use key to a huge storehouse of local energy data, is an outgrowth of several climate change mitigation initiatives by the state Legislature, the Minnesota Pollution Control Agency’s Green Step Cities program and the Regional Council of Mayors.

It enables citizens to assess emissions from residential and commercial energy use, transportation and other activities within each of the 20 cities’ borders from 2008 through 2011. Data from 2012 data will be posted later this year.

Users can sort through the data by adjusting for each city’s population, by the number of households and other factors, including distinctions for residential and commercial and industrial use. The site also has data on waste and water use, as well as on energy bills.

Rick Carter, an architect with the Minneapolis firm LHB Inc. who has been involved in sustainability efforts and led development of the site, said that state and local governments have been happy in recent years to sign on to greenhouse gas reduction pledges, but have often had no effective way to measure their progress. The site is a partial remedy for that.

One way in which it might be useful is in tracking emissions trends in communities along the proposed Southwest Corridor light rail route, said Caren Dewar, executive director of the Urban Land Institute, which helped fund the study. All communities that would be served by the rail line — Minneapolis, St. Louis Park, Hopkins, Minnetonka and Eden Prairie — have participated in the RII, and tracking their emissions before and after light rail could demonstrate whether the trains will reduce community greenhouse gas emissions, she said.

A few clicks on the site reveal that among the 20 cities analyzed:

• Duluth had the highest greenhouse gas emissions per capita from 2008 through 2011;

• Lake Elmo had the highest residential energy use per household in that period;

• Minneapolis had the third-lowest energy costs per household of the 20 cities — less than half those of Lake Elmo households.

Carter had several cautions for site users. Air travel and energy used in remote food production are not in the data, as they are in some energy-use calculations. And manipulating the data can produce some misleading results.

For instance, Falcon Heights — a city with short commutes, smallish lots and solar panels on city hall — turns up as one of the most profligate energy users and greenhouse gas emitters. That’s because its data includes the University of Minnesota’s St. Paul campus as well as all the corn roasters, deep-fat fryers and thrill rides at the State Fairgrounds. But when the data are adjusted to per-household residential electricity use, for example, Falcon Heights scored the lowest of all cities in each year studied.

Falcon Heights Mayor Peter Lindstrom said the city got involved in the assessment when it was only a three-city pilot project because officials wanted to know whether their efforts toward sustainability and greenhouse gas reductions were making a difference.

“The worst thing you can do for climate change is say you’re a green city and do things that absolutely make no difference whatsoever,” he said.

The RII, he added, provides Falcon Heights with a baseline for its own emissions, and a look at how other cities are doing.

“I think there’s room for improvement. At the same time, I just want to make sure we’re heading in the right direction,” he said.

The most significant trend to emerge in the data, in Carter’s view, is a universal upward turn in energy emissions in 2011, after a downward trend from 2008-10. Carter said he expects the line to continue upward when 2012 data arrive. He said the uptick indicates that the growing economy’s emissions have simply overwhelmed advancements in energy efficiencies and conservation.

The site is the result of a three-year, $225,000 effort paid for by the Minnesota Department of Commerce, the Minnesota Pollution Control Agency, the Urban Land Institute and the cities themselves. It may be expanded to involve 40 cities.

The website is at www.startribune.com/a2342.