As the erosion of natural capital gathers pace, those businesses that are most fleet of foot in responding will thrive. Those that do nothing may suffer unsustainable profits, cash flow problems, risks to their supply chain, and damage to brands and reputations. In this paper we examine the business issues associated with natural capital erosion, arguing that action is needed to account for the growing risks this poses to business sustainability. Natural capital depletion is the elephant in every boardroom – invisible in the vast majority of corporate decisions, accounts and economic models. To thrive in the 21st Century, business models, corporate accounting and economic modelling must all adapt. A concerted effort is underway to create methodologies and frameworks to value and account for natural capital in business. But there is much to do. Our paper argues that accountants and finance professionals have a vital role to play in helping companies navigate the challenges and opportunities which natural capital depletion will bring. Accountants have the skills, experience and oversight to draw out the connections between natural capital, commercial opportunity, business risk and, ultimately, financial performance. We suggest practical short-term steps that can be taken to start the process and catalyse a dialogue at Board level. (PDF 2MB)