How does one witness to businesspeople about climate change? Climate change is a problem for the collective and the long term, whereas business often requires a ruthless focus on the individual and the quarter. Climate change is an ethical catastrophe whose solution almost certainly requires a profoundly moral response, but talk of morality in the boardroom is often regarded with profound suspicion. Reconciling these tensions has forced me to navigate between worlds in an ongoing attempt to persuade businesspeople that solving climate change is both an economic and a moral necessity, and that the purpose of business is not only to make money but also to support the institutions that will enable us to build a sustainable world. This has not always been easy.