Tackling climate change — and thus keeping the world inhabitable — is an achievable goal, but it will become prohibitively expensive if we wait to act. This is the key message from a leaked United Nations study that The New York Times reported on last week. Journalist Justin Gillis wrote about the risk of “severe economic disruption” and “wildly expensive” solutions — ones that may not even exist — if we don’t leverage existing technologies to shift the global economy away from carbon over the next 15 years.

Talk of potential risk to humanity is not new. And we’ve seen more recently the actual devastation of record weather events like Hurricane Sandy and Typhoon Haiyan. But neither the scientific warnings nor the extreme storms have prompted enough action. However, now the risk we’re talking about is financial, which, along with the enormous economic upside of taking action, may finally get the investment community moving.

The day before the stark story in the Times appeared, I attended a related conference, the Investor Summit on Climate Risk, held at the UN and run by the NGO Ceres. Hundreds of financial executives gathered, including some heavy-hitters, from state comptrollers to executives from large pension funds to former U.S. treasury secretary Robert Rubin, who declared, “climate change is an existential risk.”

The conference was focused on the release of Ceres’ new report, “Investing in the Clean Trillion.” Created in conjunction with Carbon Tracker, the study lays out a plan for mobilizing much more capital toward building the clean economy. The trillion-dollar number is not random: The International Energy Agency (IEA) has estimated that the world needs to pour $36 trillion of investment into the clean economy between now and 2050 in order to keep the planet below the critical warming threshold of 3.6 degrees Fahrenheit (2oC). That’s $1 trillion per year.

A key target for Ceres’ work, and the main audience at the conference, is the group of institutional investors who manage tens of trillions of dollars in assets for long-term performance. The core argument to compel institutional investors to change how they influence companies and where they invest their money is simple: as the world pivots away from carbon-based energy to avoid devastating climate change, fossil fuel assets, like coal plants or off-shore oil rigs, will be “stranded” — a wonky term for “worthless.” The value of the companies owning and managing those assets, the logic goes, will plummet. As Nick Robins from the bank HSBC described to the audience, in a scenario of global peak fossil fuel use by 2020 “implies a 44% reduction in discounted cash flow value of fossil fuel companies” — or in simpler terms, a decline in share price of 40 to 60 percent.

In another Ceres meeting last fall on this topic of stranded assets, Craig Mackenzie from the Scottish Widows Investment Partnership ($200 billion in assets) spoke about the “wake-up call” investors had gotten from recent shifts in the U.S. coal market. The 20% drop in coal demand was driven mainly by the incredible increase in natural gas production due to fracking technology, not from any concern over greenhouse gases. But the rapid shift demonstrated to Mackenzie and his firm the dangers of overexposure to a class of assets. So, he says, the fund “reduced exposure to pure play coal companies to nearly zero.”

It’s easy to point out a big flaw with the stranded assets discussion: uncertainty. I spoke with executives at a few big banks who said the big question for them is when will the assets be stranded. Nobody wants to leave profitable investments too early that gets you fired. But trying to time a bubble bursting is a dangerous game. How many investors got the timing right on the implosion of mortgage-backed security assets in 2008? Nearly none, and that systemic failure of vision contributed mightily to a global financial collapse.

Given what’s at stake now — not just financial system stability, but planetary, human-supporting system stability – it’s more than prudent to avoid the game of timing the market perfectly. The investment community should be much more proactive about using its weight to a) pressure fossil fuel companies to quickly migrate their own portfolios to new forms of energy; and b) dedicate significant funds to investing directly in new technologies.

With the chilling, “it’s going to be very costly” message of Gillis’ article, and the warnings of trillions of stranded assets in the Ceres report, it’s easy to miss the very big silver lining running underneath all the dire warnings: we have the technologies today to make the shift and do it profitably.

The Clean Trillion report cites the uplifting flip side of the IEA’s calculations — the $36 trillion of investment we need will yield $100 trillion in fuel savings between now and 2050. That’s a lot of money to leave on the table, and a very good investment.