Last September, at the Clinton Global Initiative conference in New York City, I listened to a well-known Silicon Valley venture capitalist tout the green revolution. Ethanol plants, solar panels, wind turbines — the floodgates are open, he told the crowd, the money is flowing. The well-intentioned investors, hedge-fund managers, and assorted billionaires at the conference certainly were enthusiastic. What beats doing good and getting rich at the same time?

When I start feeling giddy about a venture capitalist-led revolution, however, I recall my recent visit to the Atlanta History Center. While working on a book about the coal industry, I researched an early twentieth-century businessman named Henry Atkinson, best remembered today as the founder of the Southern Company, one of the largest electric power companies — and biggest polluters — in America. Atkinson was a Yankee from a prominent Boston family; his uncle, Edward Atkinson, was an outspoken abolitionist who helped finance and arm John Brown for his disastrous raid on a military arsenal at Harpers Ferry in 1859.

Curious, I spent the day reading about Uncle Edward, a northern textile manufacturer, inventor, and respected political economist. Southern plantation owners had long made the case that the cotton industry was dependent on the captive labor of slavery — without it, the southern cotton empire would collapse. But in essays such as “Cheap Cotton by Free Labor,” Atkinson argued that rather than providing an incentive for hard work and efficiency, slavery did exactly the opposite. Atkinson believed that a “free labor” market, in which workers were paid modest wages, had many economic advantages, including motivating them to work longer and harder and freeing plantation owners from the need to supervise and care for slaves. In short, rather than lecture southerners on slavery’s moral outrages, Atkinson appealed to their greed, arguing that by abolishing slavery they could make more money. The context was different, but the logic was the same as what I heard at Clinton’s conference: a better, more efficient economic system is the best cure for social (or environmental) problems.

In the months since I encountered Atkinson’s essays, I’ve noticed other parallels between the arguments to abolish slavery and those to stop global warming. In both cases, we are often told that we are dependent on the very thing — cotton, fossil fuels — that is destroying us. In both cases, wealthy, powerful members of the status quo counter that if we do make changes life as we know it will collapse. Revolutionaries, meanwhile, herald a new world just over the horizon.

Global warming is an entirely different and far broader threat than slavery ever was, but the comparison is valuable for the lessons it reveals about how societies transform themselves. Ultimately, it wasn’t arguments for enlightened capitalism that ended slavery. It was moral clarity, backed by guns. President Lincoln understood the logic of plantation owners who argued that ending slavery would be destructive, impractical, and costly. But Lincoln knew that none of that mattered. Slavery was wrong, and it had to end. The price — in economic and human terms — was secondary.

The trouble with such moral clarity, of course, is that you can’t profit off it. Ethical capitalism is all well and good, but our current faith in it may someday look as naïve as Atkinson’s faith in free labor. Like slavery, global warming is a problem that is too big, too complex, and too deeply rooted to be solved by the lure of cold, hard cash alone.