of transportation infrastructure, though, can release carbon and reduce sequestration. Thus, offsetting here should include climate stabilization, i.e., compensating for the emissions and loss of sequestration. To date, there is one example of offsets required for loss of GHG sinks or increases in emissions due to infrastructure, a greenhouse gas regulatory regime in the State of California under state environmental protection (CEQA), where one must assess, minimize and offset shifts in carbon sinks and emissions.

However, it is not enough to do activities and claim offsets if activities did not actually lower emissions. – Studies of carbon offsets such as from projects in the Kyoto Protocol’s Clean Development Mechanism the world’s largest carbon offsetting program, with many energy and industrial types of offsets – show a lack of impact (Haya 2010). Clearly, some methods for calculating carbon impacts and carbon offsets are imperfect (Harangozo and Szigeti 2017; Johnson, Edwards, and Masera 2010). It is still the case, though, that well‐designed and stringently enforced programs could lower emissions and even have co‐benefits (e.g., some forest‐carbon efforts in the U.S. for the California market (Anderson, Field, and Mach 2017)).

# E. Spillovers and Net Impacts

– As emphasized, it is a challenge to achieve impacts via interventions of any type and purpose – avoiding, reducing, or offsetting given that simply announcing a program does not change behaviors. Simply creating a protected area does not guarantee there will be no illegal invasion and deforestation; plus, even if the trees remain standing, it does not guarantee any impact if there were not any threats. Simply creating an incentives program does not guarantee that anybody will sign up or will change any behaviors. If one is paid to keep trees standing, one might simply volunteer agriculturally useless land.

However, sometimes interventions will in fact change behaviors on those lands within their boundaries. Unfortunately, even that does not guarantee a net impact, since interventions might generate spillovers. If a protected area does in fact lower clearing relative to what would have occurred without protection, which many have done on average across the world, unfortunately it could still easily be the case that the individuals who would have cleared inside the protected area just displace their deforestation elsewhere. Within payments programs, even if one parcel that would have been cleared is not, due to payments, there is often nothing preventing a landowner from just shifting the clearing to another such parcel. Should such spillovers – in those cases “leakage” – occur, they can cancel out any positive impacts.

Conceptual models of how market demands for land clearing play out across any landscape certainly suggest that PAs could induce spillover deforestation into nearby locations (Armsworth et al. 2006). Empirical estimates of forest spillovers from PAs find heterogeneities (A. Pfaff and Robalino 2017; J. Robalino, Pfaff, and Villalobos 2015). That is in part because when lacking impact, PAs will not spill over, e.g., if threats are not taken on then they cannot be blocked, for impact, but also will not be displaced.

Spillovers tend to be higher deforestation elsewhere if interventions are nearer to roads (J. Robalino, – Pfaff, and Villalobos 2017) which is obviously relevant when considering integrated policies that place − protected areas near BRI projects and if prices for commodities whose production is displaced are high (Baylis, Fullerton, and Shah 2016). Spillovers may be less negative near PA entrances, where ecotourism tends to concentrate and to raise the value of intact forest parcels (J. Robalino, Pfaff, and Villalobos 2017), as well as when any displaced commodities’ prices are low (Baylis, Fullerton, and Shah 2016).

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