General Mills’ detailed new plan to combat climate change raises a challenging question for the alarming number of presidential candidates and political leaders who downplay or deny this global threat.

One of the oft-cited justifications for inaction on the issue is that remedies to prevent the Earth’s temperature from rising to dangerous levels are thought to be bad for business and the economy. But if that’s truly the case, why has the leadership team at this Minnesota-based company, one of the world’s largest food firms, decided that taking dramatic action is crucial for future success?

In fact, General Mills has long been a leader on climate change. Recently, it was one of the nation’s most influential firms to publicly support the U.S. Environmental Protection Agency’s Clean Power Plan, which will limit power plants’ carbon-dioxide emissions. Carbon dioxide, a so-called “greenhouse gas,” is a climate-change accelerant.

This summer, Wal-Mart, Unilever and other firms reliant on agricultural products generated positive national press when they agreed — after a presidential push to do so — to encourage their suppliers to reduce carbon. But General Mills this week distinguished itself by rolling out an ambitious road map to make it happen.

On Monday, the venerable maker of cereal, yogurt and other household essentials announced its aim to reduce greenhouse-gas emissions by 28 percent by 2025. The firm also will invest more than $10 million a year over the next decade in clean energy and energy efficiency.

The changes, of course, will involve far more than the company’s head office in Golden Valley. In an interview, John Church, an executive vice president, said General Mills will focus on its long supply chain. It will push suppliers to use best practices for sustainable production of the ingredients needed for General Mills’ products — and then reward suppliers for doing so, such as through longer-term contracts, for example.

The company will also help consumers reduce their carbon footprint by improving packaging for more than 3,000 products and introducing more organic products.

“When a major food supplier like General Mills says climate change is real, it’s time to listen. When they say it’s in their business interest to reduce emissions, we can be sure they’ve run the numbers,’’ said Bob Inglis, a former Republican congressman who now leads the RepublicEn.org initiative at George Mason University. “[CEO] Ken Powell and his company are displaying the kind of problem-solving leadership that makes America great and that can repair our political process.”

General Mills is pragmatically hoping that its involvement will lead to a more informed debate and spur other companies to realize that protecting the health of current and future customers makes solid business sense. It’s not only a welcome example of good corporate citizenship, but could also be a game-changer in the battle against climate change.