This chapter draws on the quantitative analysis in Chapter 2 and further empirical evidence to identify barriers to and opportunities for scaling up the mobilisation of private finance for climate action in developing countries. It explores (i) policy, regulatory and wider constraints in recipient countries and their impact on investor perceptions; (ii) hurdles to private investment and possible solutions in two key areas: clean energy, and agriculture and forestry; and (iii) constraints within the multilateral development architecture that limit private capital mobilisation. Scaling up the mobilisation of private finance requires system-wide action: concerted efforts to improve the conditions for private investment in developing countries; more effective use of public climate finance to crowd-in investment; and strengthening of the international climate finance architecture, notably multilateral development banks, to more effectively partner with the private sector.