Tropical deforestation is estimated to cause about one-quarter of anthropogenic carbon emissions, loss of biodiversity, and other environmental services. United Nations Framework Convention for Climate Change talks are now considering mechanisms for avoiding deforestation (AD), but the economic potential of AD has yet to be addressed. We use three economic models of global land use and management to analyze the potential contribution of AD activities to reduced greenhouse gas emissions. AD activities are found to be a competitive, low-cost abatement option. A program providing a 10% reduction in deforestation from 2005 to 2030 could provide 0.3–0.6 Gt (1 Gt = 1 × 10⁵g) CO₂·yr⁻¹in emission reductions and would require $0.4 billion to $1.7 billion·yr⁻¹for 30 years. A 50% reduction in deforestation from 2005 to 2030 could provide 1.5–2.7 Gt CO₂·yr⁻¹in emission reductions and would require $17.2 billion to $28.0 billion·yr⁻¹. Finally, some caveats to the analysis that could increase costs of AD programs are described.

Land‐based climate mitigation measures have gained significant attention and importance in public and private sector climate policies. Building on previous studies, we refine and update the mitigation potentials for 20 land‐based measures in >200 countries and five regions, comparing “bottom‐up” sectoral estimates with integrated assessment models (IAMs). We also assess implementation feasibility at the country level. Cost‐effective (available up to $100/tCO₂eq) land‐based mitigation is 8–13.8 GtCO₂eq yr⁻¹between 2020 and 2050, with the bottom end of this range representing the IAM median and the upper end representing the sectoral estimate. The cost‐effective sectoral estimate is about 40% of available technical potential and is in line with achieving a 1.5°C pathway in 2050. Compared to technical potentials, cost‐effective estimates represent a more realistic and actionable target for policy. The cost‐effective potential is approximately 50% from forests and other ecosystems, 35% from agriculture, and 15% from demand‐side measures. The potential varies sixfold across the five regions assessed (0.75–4.8 GtCO2eq yr⁻¹) and the top 15 countries account for about 60% of the global potential. Protection of forests and other ecosystems and demand‐side measures present particularly high mitigation efficiency, high provision of co‐benefits, and relatively lower costs. The feasibility assessment suggests that governance, economic investment, and socio‐cultural conditions influence the likelihood that land‐based mitigation potentials are realized. A substantial portion of potential (80%) is in developing countries and LDCs, where feasibility barriers are of greatest concern. Assisting countries to overcome barriers may result in significant quantities of near‐term, low‐cost mitigation while locally achieving important climate adaptation and development benefits. Opportunities among countries vary widely depending on types of land‐based measures available, their potential co‐benefits and risks, and their feasibility. Enhanced investments and country‐specific plans that accommodate this complexity are urgently needed to realize the large global potential from improved land stewardship.

Woody bioenergy demand and carbon sequestration payments increase forest area and produce net carbon benefits.

Carbon terrestrial sinks are seen as a low-cost alternative to fuel switching and reduced fossil fuel use for lowering atmospheric CO2. In this study, we review issues related to the use of terrestrial forestry activities to create CO2 offset credits. To gain a deeper understanding of the confusing empirical studies of forest projects to create carbon credits under Kyoto, we employ meta-regression analysis to analyze conditions under which forest activities generate CO2-emission reduction offsets at competitive "prices." In particular, we examine 68 studies of the costs of creating carbon offsets using forestry. Baseline estimates of costs of sequestering carbon are some US$3–$280 per tCO2, indicating that the costs of creating CO2-emission offset credits through forestry activities vary wildly. Intensive plantations in the tropics could potentially yield positive benefits to society, but in Europe similar projects could cost as much as $195/tCO2. Indeed, Europe is the highest cost region, with costs in the range of $50–$280 per tCO2. This might explain why Europe has generally opposed biological sinks as a substitute for emissions reductions, while countries rush to finance forestry sector clean development mechanism projects. In Canada and the U.S., carbon sequestration costs range from a low of about $2 to nearly $80 per tCO2. One conclusion is obvious: some forestry projects to sequester carbon are worthwhile undertaking, but certainly not all.