Regulation to control carbon emissions challenges firms to develop optimal carbon management policies. We set out a unified approach to study the trade-offs carbon pricing poses for firms and how they should therefore best respond. Our model shows that while carbon pricing curtails firms’ carbon emissions, polluting firms tilt their green investment mix towards more immediate yet short-lived options – such as solely reducing emissions (abatement) instead of investing in green innovation – as it becomes costlier to comply. Under emissions trading systems, larger balances of carbon credits dampen firms’ efforts to reduce their carbon emissions. Our analysis reveals that carbon regulation does not necessarily reduce shareholder value if firms are sufficiently committed to reducing their carbon footprint.