Faced with this collective public yawn, many environmental activists have chosen to bang the drums and spread the message that the earth really does face an apocalypse. Alas, there’s not much evidence this strategy works over time. For awhile, it may spark enough of a sense of crisis to propel some action. But then the concern wears off and the action winds down.

This, in essence, has been the trajectory of the first phase of the modern sustainability push. In 2005, amid mounting scientific warnings about the dangers of global warming, the European Union slapped a price on carbon-dioxide emissions; the rules forced businesses constituting a large swathe of the E.U.’s industrial economy to curb their emissions or to buy permits to pollute. In 2007, the year after the release of Al Gore’s cinematic cri de coeur about climate change, An Inconvenient Truth, GE bought its stake in the Colorado solar-panel maker PrimeStar. At the time, GE was just one of dozens of companies making similar renewable-energy investments. The rationale: A combination of government incentives, consumer interest and technological innovation would boost the market for solar power, making it a profitable piece of the energy business.

What did that spasm of green spending produce? Environmentally speaking, not a lot. The price of a European permit allowing the bearer to emit a ton of carbon dioxide has plummeted, from about 30 euros in 2005 to about 5 euros today. That’s a fair sign the market isn’t inducing much change. Even if Europe’s carbon market had thrived, it wouldn’t have done much for the atmosphere, because the developing world — a place not covered by Europe’s carbon policies — is expected to produce virtually all the growth in global greenhouse-gas output in coming years. As for renewable-energy investments by companies such as GE, they’ve helped slash the price of solar panels and wind turbines, no small achievement. Yet renewable energy remains a small slice of the global energy pie, and greenhouse-gas emissions continue to rise, largely because the developing world is burning more coal and oil than ever.

But just because the first round of modern environmental spending has been inefficient doesn’t mean the next round must be too. Today, institutions with unsentimental investors are ramping up strategies that could accelerate a shift toward an economy that uses natural resources more efficiently — a shift that will stick to the extent that it proves lucrative. Big electric utilities are buying into the renewable-energy business, often more aggressively than governmental clean-energy mandates require them to do. To be sure, they’re angling to look green, they’re still making most of their power profit from fossil fuel, and often they’re lobbying against tougher renewable-energy policies even as they make those investments. What’s changing, though, is that they’ve decided that renewable energy has grown too big to ignore. Utilities that set investment strategy for decades, not just for months or years, are concluding that the cost of renewable energy has declined to the point that, in some places, it’s competitive with conventional power.