Probability-based accounting for carbon in forests to consider wildfire and other stochastic events: synchronizing science, policy, and carbon offsets

Abstract

Forest carbon offset protocols reward measurable carbon stocks to adhere to accepted greenhouse gas (GHG) accounting principles. This focus on measurable stocks threatens permanence and shifts project-level risks from natural disturbances to an offset registry's buffer pool. This creates bias towards current GHG benefits, where greater but potentially high-risk stocks are incentivized vs. medium-term to long-term benefits of reduced but more stable stocks. We propose a probability-based accounting framework that allows for more complete risk accounting for forest carbon while still adhering to International Organization for Standardization (ISO) GHG accounting principles. We identify structural obstacles to endorsement of probability-based accounting in current carbon offset protocols and demonstrate through a case study how to overcome these obstacles without violating ISO GHG principles. The case study is the use of forest restoration treatments in fire-adapted forests that stabilize forest carbon and potentially avoid future wildfire emissions. Under current carbon offset protocols, these treatments are excluded since carbon stocks are lowered initially. This limitation is not per se required by ISO's GHG accounting principles. We outline how real, permanent, and verifiable GHG benefits can be accounted for through a probability-based framework that lowers stressors on a registry's buffer pool.

Mitigating risk of credit non-delivery in nature-based climate solutions by optimally anticipating carbon release

“…Our approach dynamically adjusts the optimal release schedule based on observed carbon drawdown distributions updated with new observed data, allowing for credit permanence to be evaluated from an early stage, and for additional credits to be generated whenever the project performs better than predicted. This creates incentives for project developers and local communities to maintain long-term project custodianship, which has been identified as one of the key components needed for projects to be successful and effective [29][30][31]. It may also provide a form of inter-generational equity, as future custodians of a project can receive credits from safeguarding the drawdown achieved in the past, as opposed to simply being expected to look after it without any reward.…”

Insuring against variability in the performance of Nature-Based Climate Solutions

“…Our approach dynamically adjusts the optimal release schedule based on observed carbon drawdown distributions updated with new observed data, allowing for credit permanence to be evaluated from an early stage, and for additional credits to be generated whenever the project performs better than predicted. This creates incentives for project developers and local communities to maintain long-term project custodianship, which has been identified as one of the key components needed for projects to be successful and effective [29][30][31]. It may also provide a form of inter-generational equity, as future custodians of a project receive credits from safeguarding the drawdown achieved in the past, as opposed to simply being expected to look after it without any reward.…”