Supervisors around the world wish to ensure that the financial system is resilient to climate change. To that end, current best practice is to formulate detailed long-run climate scenarios and then ask whether financial institutions, especially banks, can withstand the losses associated with them. These scenarios typically map the path of surface temperature, sea level, and the resulting economic damage over the next 30 or 40 or 50 years.

However, financial-system stress arises from sudden, widespread changes in the value and perceived quality of leveraged intermediaries’ assets, while climate change is likely to remain gradual over decades. As a result, skeptics reasonably doubt that climate change poses systemic financial risk sufficient to merit the use of scarce supervisory resources and a costly testing apparatus. To quote John Cochrane: “[B]anks did not fail in 2008 because they bet on radios not TV in the 1920s. Banks failed over mortgage investments they made in 2006.”

Fortunately, we now have low-cost, high frequency, forward-looking tools for monitoring climate-related sources of financial instability. In this post, we use one such tool to identify episodes in which the potential influence of climate change on systemic resilience may be worthy of attention. We also look at how an aggregate measure of financial system vulnerability evolves over time….