3.0 Challenges, Risks and Critiques of PES As mentioned earlier, despite the promise and potential of PES, and the availability of successful implementations across multiple ecosystems, its adoption has been slow and insubstantial. With regard to the operational risks and project uncertainties – these are well understood across domains and there is significant expertise to solve them effectively – those cannot be the reasons to not adopt a PES-based programme. This chapter outlines the key challenges, risks, and critiques that prevent mainstreaming and a more widespread uptake of PES. reaching the impoverished and vulnerable.The World Wildlife Fund, along with partners, has set up the Targeting Natural Resource Corruption consortium that outlines corruption risks and anti-corruption responses in sustainable livelihood interventions, including mapping out a PES results chain(known as Miradi Share) to integrate anti-corruption responses in a PES chain (Whitt, 2022). Transparent monitoring and measurement of impact helps ensure that there isn't 'impact-washing' with PES implementation. 3.1 Challenges Three broad challenges exist, the first being capital. Not only is there insufficient access to upfront and working capital, but long-time horizons are also not conducive to capital markets' flow. When it comes to stakeholders, governments and philanthropy continue to play the major role and there is limited involvement of impact investors – this leads to less innovation on-the-ground. Finally, for any financial scheme, returns are key. When it comes to PES, the risk-return profiles are not well understood by the investment community, at the same time, measurement practices and approaches are non­standard and often rudimentary. 3.2 Risks For PES to succeed, the enforcement of property rights and the risk of changes in land management rules and regulations have a significant impact on ecosystem service delivery and design of the PES intervention. Secondly, leakages can occur when the provision of ecosystem services in one location increases pressure for conversion in another, even if it is inappropriate for the PES intervention. For example, there is already a worrying trend towards monoculture plantations during afforestation/reforestation, since this is known to adversely impact biodiversity and the long-term sustainability of the forest. Finally, like any scheme, the risks of corruption and abuse are ever present- especially when it comes to the benefits Biophysical risks are typically viewed as an intrinsic component of any PES programme. However, it's important to recognise that, in specific cases, natural disasters, pests, and diseases can disrupt landowners' capacity to deliver ecosystem services, potentially resulting in service interruptions and payment disputes. The adversities, depending on the specific design and context of a PES programme will always remain, and yet, they can often be mitigated through careful programme design and sustained stakeholder engagement. 3.3 Critiques The main critique is philosophical: is it appropriate to value natural systems, and if we do, can we ascribe a real monetary value to them. Sir John Lawton says it effectively:“Arguing that the natural world is priceless is deeply mistaken. Recognising the economic value of the natural world for society provides a framework for the voluntary, public and private sectors to work together” (Lawton, and others, 2010). The cultural and ethical concerns surrounding the commercialisation of nature and the monetisation of ecosystem services still divert the necessary focus needed to drive momentum in PES implementation. The other critique is behavioural: the unintended effects on human behaviour, such as the use of PES for ecosystems that the owner was anyway planning to protect and preserve; or leakage, wherein one area is preserved at the expense of another. 13 Payments for Ecosystem Services