The planet is getting hotter, and sooner or later world governments are going to be forced to take action. Regulation may not be happening fast enough to stop the irreversible damage predicted from a two-degree (Celsius) rise in global temperature, but action will happen eventually and some investors are beginning to show concern. Just last week, Bloomberg LP released a “Carbon Risk Valuation Tool “intended to help its high-end portfolio managers assess the risk ofso called ‘stranded assets’ . The tool estimates that BP stands to lose 43 percent of its stock value if governments ever get serious about regulating emissions. To understand “stranding” better, I talked earlier this month with John Fullerton, a former oil and gas investor for JP Morgan:

“The reality is that climate change and finance are still viewed as separate worlds…. Mainstream investors still dismiss it as “not our issue,”” said Fullerton, President and Founder of The Capital Institute.

Continued investment in fossil fuels is creating what is called a “carbon bubble,” he explained. A bigger, more malignant financial dilemma than its predecessor, the housing bubble; in order for the world to reduce emissions, climate scientists estimate that two-thirds of today’s fossil fuel reserves need to stay in the ground. The UN Climate Chief Christiana Figueres told energy executives as much, when she addressed a coal industry conference last month. “It’s time to honestly assess the financial risks of business as usual,” said Figueres.

But “stranding” enough fossil fuel to head off climate catastrophe will be costly for the countries with publicly held reserves, for the energy companies and the people whose pension funds are currently invested in them. Energy companies, Fullerton estimates, would need to take a $20 trillion write-off, way more than the estimated $2 trillion lost in the subprime mortgage meltdown.

How likely are companies to take action themselves? “Not likely” says Fullerton. A better bet is that investors, out of self-interest, will wise up. If not self-interest, then public pressure. A campaigns has been growing across college campuses demanding that universities divest from fossil fuels, as they once campaigned for divestment from apartheid South Africa.

So far the results have not been encouraging. Says Fullerton of Brown and Harvard’s decision not to divest:

“The president of [Brown] issued a long and thoughtful statement on their decision on why they should not divest, and to be honest, I fully sympathize with all of the economic arguments…but I do think if we look back at that letter, maybe even only five years from now, and substitute the word fossil fuel perhaps with the word slavery we will be aghast at how we thought about this issue. Our leading public institutions are letting us down”

The pressure on college boards is rising—in the US and abroad thanks to campaigns like 350.0rg’s “Fossil Free.” For more on this, check out my interview with Fullerton in full, or this commentary, Climate Catastrophe or Crash?

Lee Fang reports on the fracking industry’s response to environmentalist Josh Fox’s ‘Gasland’ films.