Illinois is one of six states that together account for about a fifth of the nation's carbon emissions output. So it has been gratifying to see a clean-energy monitoring group praise the state's leadership in advancing the drive toward cleaner energy that is critical in the fight against human-caused climate change.

In a State Climate Scorecard issued June 30, the nonprofit Rocky Mountain Institute, also known as RMI, placed Illinois alongside California, Colorado, New Jersey, New York and Washington as states both with the most potential impact on carbon reduction and the most progress toward climate-policy bench marks.

"We think Illinois is really critical to what's happening to the whole country," study co-author Jacob Corvidae told our Jenny Whidden for a report Sunday on the study, "and we'd like that leadership to continue."

That objective, though, is by no means assured, despite the state's early progress -- credited primarily to the Clean Energy Jobs Act that became law last September. For while the state scores well on RMI's rankings for clean energy production, it stumbles for the moment when it comes to policies involving industry, buildings and transportation, and its achievements toward electricity production trace primarily to the use of nuclear power, a strong source of clean energy whose benefits are challenged by an aging nuclear infrastructure and a nuclear ban dependent on the development of so-far-nonexistent federal policy on nuclear waste disposal.

Whether Illinois should lift its ban on new nuclear power is the subject of legislation introduced in the state Senate and its merits are a topic for another time. But ban or no ban, the state's existing nuclear infrastructure, which produces more than half our electricity, is aging and in the best of cases, would be hardput to be replaced or supplemented soon enough to have a material impact on our goals of reaching 100% clean energy by 2050. Instead, we'll need more work to hasten development of renewable energy sources.

Fortunately, legislative and policy leaders in the state recognize the need for more robust policy on renewables. The CEJA legislation specifically demands a doubling of the state's investment in renewable resources and promotes efforts toward increasing the number of clean-emissions electric vehicles on our roads.

RMI's report puts it this way: "Despite a variety of climate policies already in place, Illinois still has substantial work to do. Effectively decarbonizing the state's electric grid will require substantial build-out of renewables and grid modernization while retiring fossil power plants early."

That's no small objective. The RMI report suggests we've made a good start, though we still have far to go. Fortunately, we have a policy vision that promises success -- as long as we can stick to it.