Land purchases, offsets, and conservation payments are three examples of policy instruments used to achieve conservation goals and mitigate climate change. Credit: USDA
Scientists and managers often focus on two main strategies to conserve species under climate change: the creation of movement pathways to support range shifts, and the creation of climate refugia. While one (or both) of these strategies may be promising for a region, they also must be economically feasible to implement. How do these two strategies compare in terms of both ecological effectiveness and cost effectiveness?
Few studies have attempted to conduct an economic analysis of biodiversity conservation in the context of climate change. To fill in this gap, a comprehensive study evaluates different policy instruments used to mitigate climate change. The focus is on three commonly used instruments: 1) land purchases by conservation agencies; 2) offsets, where landowners voluntarily implement conservation measures to compensate for development projects elsewhere; and 3) conservation payments for implementing specific conservation measures or achieving conservation goals. These methods are evaluated according to a detailed set of criteria that focus on both ecological effectiveness and cost effectiveness.
This economic evaluation reveals a common answer to the question of which policy instrument is most effective: it depends. A policy instrument may be well suited for one strategy but not the other, and it depends on values determined beforehand.
The trade-offs between economic goals and conservation goals highlight the importance of establishing priorities before making plans. Credit: USDA NRCS
Several trade-offs exists between cost and conservation. There is often a trade-off between spatial flexibility and habitat persistence that influences which policy instrument might be best. For example, habitat persistence is important for conserving climate refugia, but spatial flexibility is important for supporting range shifts. Habitat persistence is difficult to achieve with short-term instruments such as conservation payments, but long-term instruments such as land purchases and offsets generally have less spatial flexibility.
There is also a trade-off between the benefit-cost ratio and the bargaining power of landowners. With conservation payments, landowners have low bargaining power because payments are fixed, but sites often have low conservation value. In contrast, with offsets or land purchases the conservation value of a site may be high, but landowners have high bargaining power to ask for greater compensation because their site is essential to conservation goals.
In sum, the most effective policy instrument is one that best aligns with explicitly stated goals and balances out competing needs. More research into the benefits and drawbacks to different climate change policy instruments could help address both ecological and economic factors. Integrating economic costs into conservation decisions provides for more realistic planning and a better chance of success towards reaching conservation goals.
Resources
Gerling, C. and Wätzold, F. 2021. An economic evaluation framework for land‐use‐based conservation policy instruments in a changing climate. Conservation Biology 35(3): 824-833.
Guidance for modeling and mapping climate-wise landscape connectivity (July 2018)
