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Aim: Colombia has committed to ambitious forest restoration targets which include a 1 million ha Bonn Challenge commitment and 6.47–8.31 million ha (rehabilitation and restoration, respectively) under the National Restoration Plan. Determining where and how to implement programs to achieve these targets remains a significant challenge. Location: Colombia. Methods: We adopt a multi‐objective optimisation framework for restoration planning and apply it to Colombia. We explore cost‐effective solutions that leverage the potential for assisted natural regeneration benefits while accounting for opportunity and establishment costs of restoration and maximising biodiversity conservation and climate change mitigation benefits. We explore four politically relevant restoration area‐based targets (1, 6, 6.47 and 8.31 million ha) and identify minimum cost, and suites of maximum benefit and cost‐effective solutions. Results: We identify solutions that simultaneously perform well across biodiversity and carbon objectives, despite trade‐offs between these objectives. We find that cost‐effective solutions can achieve on average 91.1%, 90.8%, 90.5% and 90.1% of maximum carbon benefit and 100% of the maximum biodiversity benefit while significantly reducing costs. On average, the cost‐effective solutions reduce the cost by 87.5%, 56.8%, 59.6% and 46.2% compared to the maximum benefit solutions considering one, six, 6.47 and 8.31 million ha restoration targets, respectively. Main Conclusions: Colombia has committed to bold restoration and conservation targets, such as those under the new 2030 Convention on Biological Diversity Global Biodiversity Framework. Strategic forest restoration planning will play an important role in achieving Colombia's biodiversity conservation and climate mitigation goals. We provide quantitative evidence to inform planning for environmentally and economically sensible restoration policy and practice in the country. Our framework and results can help guide Colombia towards meeting its ambitious forest restoration targets cost‐effectively. [ABSTRACT FROM AUTHOR]

Wetland plants form blue carbon ecosystems, which are key for climate change mitigation yet threatened by multiple local and global stresses. The capacity of blue carbon ecosystems to store large amounts of carbon relies on ecological processes, many of them regulated by plant traits that are shaped by the stress that plants encounter.This manuscript provides a perspective to investigate the effects of stress on carbon storage and sequestration capacity of blue carbon ecosystems based on the plant traits.A first step was to identify the biochemical, physiological, morphological and growth and development traits involved in the processes controlling carbon storage and sequestration in blue carbon ecosystems.Second, the existing knowledge on the stress effects on blue carbon processes and ecosystems was evaluated.Finally, the application of the trait‐based approach to understand and predict carbon dynamics in blue carbon ecosystems under different stresses' feedback was discussed.The conclusions provide key recommendations for a trait‐based approach in which the trinomial local and global stresses, plant traits and blue carbon are embraced together to identify the feedbacks between them, along with specific attention to the plant traits across the seascape, the stress interactions and the need of plant trait standardization. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Given the increasing attention to climate change and rising CO2 (CCRC) in the global carbon cycle, we remain unclear about how China's unprecedented land use/cover change (LUCC) in the carbon budget has been affected by CCRC in recent decades. Here, we combined remotely sensed land use/cover (LUC) datasets and the Biome‐BGCMuSo model to address this issue by setting different scenarios. We found that LUCC led the carbon sink to increase by approximately 104.24 ± 46.52 Tg C without considering CCRC during 1990–2020. Carbon sinks contributed by afforestation (374.97 ± 36.50 Tg C) and grassland planting (15.75 ± 9.11 Tg C) offset other LUC trajectories caused carbon loss (286.47 ± 32.18 Tg C, 87.33% owing to agricultural reclamation). LUCC contributed carbon sinks were amplified by ∼20% under CCRC at the national scale. This rate increased to 106.03% in northeast China but decreased to −26.68% in southern China. CCRC led carbon sink contributed by afforestation amplified by 85.11% in northeastern China but was only 26.35% in southern China. CCRC amplified carbon emissions due to agricultural reclamation by 103.20% in northeastern China and by 25.09% in southern China. Our results demonstrated that ecological restoration projects are efficient in enhancing carbon sinks and mitigating emissions. Divergent amplifying/reducing effect of CCRC across different geographic regions implied the sensitivity of different LUC trajectories to CCRC varied with different climate backgrounds. Land management strategies should be implemented with spatial heterogeneity to amplify afforestation and grassland planting contributed carbon sinks and decrease other LUC trajectories caused carbon loss under the global change environment. Plain Language Summary: It is undoubted that climate change and rising CO2 (CCRC) would alter the effect of land use/cover change (LUCC) on the carbon budget. However, to what extent CCRC will influence the effect of LUCC on the carbon budget remains unclear. In this work, we evaluated the impact of CCRC on the carbon budget change caused by LUCC. We found that CCRC would amplify or dampen the impact of LUCC on the carbon budget. Meanwhile, this amplifying or dampening rate was divergent in different geographic regions. Our work provides new insights for making climate change mitigation targeted land decisions to increase carbon sinks with ecological restoration and construction and reduce emissions through protection. Key Points: Afforestation and grassland planting offset other land use/cover change (LUCC) caused carbon loss and continue to increase carbon sinkClimate change and rising CO2 (CCRC) amplified China's LUCC contributed carbon sinks by approximately 20%CCRC amplified carbon sink induced by LUCC in northeastern China, reduced it in southern China [ABSTRACT FROM AUTHOR]

Subtidal seabed sediments are one of the planet's biggest organic carbon stores, but have been poorly considered in nature‐based climate change mitigation. Protection of the seabed is predominantly through establishment of marine protected area (MPA) networks, but their emphasis on biodiversity may limit their carbon value. The United Kingdom has one of the most extensive networks of MPAs in the world, yet damaging human activities are excluded from only a small portion. We calculate that full protection of the MPA network would offer limited carbon benefit, due to below average organic carbon stocks and disturbance from mobile fishing gears when compared to the entire U.K. seabed. We find that inshore exclusion zones (where mobile gears are restricted from nearshore areas to benefit biodiversity and low‐impact fishers) could offer greater carbon benefits compared to MPAs. However, neither of these biodiversity‐focused protection strategies are as effective for seabed carbon as targeted protection. [ABSTRACT FROM AUTHOR]

Reducing emissions from deforestation and forest degradation (REDD+) projects aim to contribute to climate change mitigation by protecting and enhancing carbon stocks in tropical forests, but there have been no systematic global evaluations of their impact. We used a new data set for tropical humid forests and a standardized evaluation approach (based on pixel matching) to quantify the performance of a representative sample of 40 voluntary REDD+ projects in 9 countries certified under the Verified Carbon Standard (VCS). In the first 5 years of implementation, deforestation within project areas was reduced by 47% (95% confidence interval [CI]: 24–68) compared with matched counterfactual pixels, and degradation rates were 58% lower (95% CI: 49–63). Reductions were small in absolute terms but greater in sites located in high‐deforestation settings and did not appear to be substantially undermined by leakage activities in forested areas within 10 km of project boundaries. At the 26th Conference of the Parties of the United Nations Framework Convention on Climate Change, the international community renewed its commitment to tackling tropical deforestation as a nature‐based solution to climate change. Our results indicate that incentivizing forest conservation through voluntary site‐based projects can slow tropical deforestation and highlight the particular importance of prioritizing financing for areas at greater risk of deforestation. [ABSTRACT FROM AUTHOR]

The magnitude and variability of mangrove carbon storage are uncertain and still being discussed. In a recent article, Breithaupt and Steinmuller (2022, https://doi.org/10.1029/2022GL100177) completed a literature review and compared mangrove organic carbon burial rates between different coastal environmental settings (CES) that integrate sedimentary supply (terrigenous vs. carbonate) and hydrogeomorphic settings (delta, estuary, lagoon, open coast). They found greater burial rates in terrigenous delta and estuaries while lower rates were reported in lagoons and carbonate settings. Surprisingly, these CES relationships do not strictly match previous mangrove soil carbon stock estimates but were consistent with biomass stocks. The CES approach used by Breithaupt and Steinmuller should be used for other mangrove carbon stocks and fluxes estimates to refine our understanding of mangrove carbon cycling and storage. Plain Language Summary: Mangrove forests are intertidal ecosystems efficient at trapping carbon in their sediments. While this ecological process is well recognized, the quantity of carbon being deposited is still uncertain. Considering the growing number of studies that have collected samples to estimate carbon burial rates, Breithaupt and Steinmuller (2022, https://doi.org/10.1029/2022GL100177) recently published a meta‐analysis to compile and compare carbon burial between mangrove types. Their study reported great variability between mangrove types based on their sediment supply and geomorphological configuration. Their results are interesting because they go against previous estimates of mangrove carbon stocks distribution. Also, the approach used has the potential to be applied to other components of the mangrove carbon budget. Doing so would improve our fundamental understanding of carbon cycling in mangrove ecosystems. It would also help refine carbon storage estimates for future conservation projects interested in generating carbon credits. Key Points: Carbon burial rates between mangrove sedimentary and geomorphic types were analyzed in Breithaupt and Steinmuller (2022, https://doi.org/10.1029/2022GL100177)Greater carbon burial rates were reported in terrigenous deltas and estuaries rather than in lagoons and carbonate settingsComparing carbon burial rates with other stocks and fluxes between mangrove types can help refine the global mangrove carbon budget [ABSTRACT FROM AUTHOR]

The development and refinement of methods for estimating organic carbon accumulation in biomass and soils during mangrove restoration and rehabilitation can encourage uptake of restoration projects for their ecosystem services, including those of climate change mitigation, or blue carbon. To support the development of a blue carbon method for Australia under the Emission Reduction Fund scheme we investigated; (1) whether carbon accumulation data from natural mangroves could be used to estimate carbon accumulation during restoration; (2) modeling mangrove biomass accumulation; and (3) how modeled carbon accumulation could be achieved over heterogeneous sites. First, we assessed carbon accumulation in soil and biomass pools from the global literature, finding that estimating carbon accumulation using data from natural mangroves provided similar estimates as those for restored or rehabilitated mangroves. We assessed mangrove biomass accumulation from global chronosequence studies, which we used to develop regional models for estimating biomass accumulation with restoration in Australia using values from local natural mangroves. Estimating biomass carbon accumulation using site‐based means of stand biomass provided similar estimates as values estimated through use of regional means values stratified by elevation; and reduced overestimates of biomass carbon accumulation that were based on regional mean values. Modeling soil carbon accumulation over environmentally heterogeneous project sites can apply a similar approach, stratifying over variation in site elevation. Our analysis provides a strategy for modeling blue carbon pools for an Australian blue carbon method that accommodates regional differences and is based on data from natural mangroves. [ABSTRACT FROM AUTHOR]

Improving the global monitoring of above‐ground biomass (AGB) is crucial for forest management to be effective in climate mitigation. In the last decade, methods have been developed for estimating AGB from terrestrial laser scanning (TLS) data. TLS‐derived AGB estimates can address current uncertainties in allometric and Earth observation (EO) methods that quantify AGB.We assembled a global dataset of TLS scanned and consecutively destructively measured trees from a variety of forest conditions and reconstruction pipelines. The dataset comprised 391 trees from 111 species with stem diameter ranging 8.5 to 180.3 cm and AGB ranging 13.5–43,950 kg.TLS‐derived AGB closely agreed with destructive values (bias <1%, concordance correlation coefficient of 98%). However, we identified below‐average performances for smaller trees (<1,000 kg) and conifers. In every individual study, TLS estimates of AGB were less biased and more accurate than those from allometric scaling models (ASMs), especially for larger trees (>1,000 kg).More effort should go to further understanding and constraining several TLS error sources. We currently lack an objective method of evaluating point cloud quality for tree volume reconstruction, hindering the development of reconstruction algorithms and presenting a bottleneck for tracking down the error sources identified in our synthesis. Since quantifying AGB with TLS requires only a fraction of the efforts as compared to destructive harvesting, TLS‐calibrated ASMs can become a powerful tool in AGB upscaling. TLS will be critical for calibrating/validating scheduled and launched remote sensing initiatives aiming at global AGB mapping. [ABSTRACT FROM AUTHOR]

Forest biomass is an important component of terrestrial carbon pools. However, how climate, biodiversity, and structural attributes co‐determine spatiotemporal variation in forest biomass remains not well known. We aimed to shed light on these drivers of forest biomass by measuring diversity and structural attributes of tree species in 400‐m2 plots located every 100 m along a 4200‐m elevational gradient in the eastern Himalayas. We applied structural equation models to test how climate, species richness, structural attributes, and their interactions influence forest biomass. Importantly, species richness was a stronger driver of biomass than environmental and structural attributes such as annual air temperature or stem density. Integrating the availability of energy and the demand for water, potential evapotranspiration was more strongly correlated with biomass than water availability, likely due to the strong influence of the Indian summer monsoon. Thus, interactions between climate and tree community composition ultimately control how much carbon is stored in woody biomass across bioclimatic gradients. This fundamental understanding will support predictive efforts of the forest carbon sink in this hydroclimatically important region and help preserving regional forests as a potent natural solution for climate change mitigation. [ABSTRACT FROM AUTHOR]

On a warming planet, a key challenge natural resource managers face is protecting wildlife while mitigating climate change—as through forest carbon storage—to the greatest extent possible. But in some ecosystems, habitat restoration for imperiled species may be incompatible with maximizing carbon storage. For example, promoting early successional forest conditions does not maximize stand‐level carbon storage, whereas uniformly promoting high stocking or mature forest conditions in the name of carbon storage excludes species that require open or young stands. Here, we briefly review the literature regarding carbon and wildlife trade‐offs and then explore four case studies from the Northern Forest region of the United States. In each case, human activities have largely dampened the influence of natural disturbances; restoring or emulating these disturbances is typically required for habitat restoration even when doing so equates to less carbon storage at the stand level. We propose that applying a climate adaptation lens can help managers and planners navigate these trade‐offs and steer away from maladaptive practices that may ultimately reduce adaptive capacity. Instead, critically evaluating the consequences of stand‐level management actions on both carbon and wildlife can then facilitate landscape‐scale climate adaptation planning that supports a diversity of habitats alongside opportunities to invest in maximizing forest carbon. [ABSTRACT FROM AUTHOR]

Disturbance of marine sediments results in the remineralization of sedimentary organic matter (OM) and impacts upon natural burial processes. Management interventions which restrict or remove activities that cause seabed disturbance may offer effective strategies to protect the most vulnerable of these shelf sea OM stores, offering new opportunities to deliver climate mitigation actions. While the largest quantities of OM are often stored in the expansive offshore regions of continental shelves and might therefore suggest appropriate zones for management interventions to protect vulnerable OM stores, our results highlight that these offshore regions generally contain OM of low reactivity. Conversely, inshore and coastal sediments store significant quantities of highly reactive OM that is at greater risk of remineralization when disturbed. The marked spatial disparities between OM reactivity across shelf sea sedimentary environments highlights the need to focus emergent policy and future management interventions toward the protection of inshore and coastal sediments. Plain Language Summary: If disturbed, the organic carbon within seafloor sediments can potentially be converted to carbon dioxide and a portion lost to the atmosphere, where it potentially contributes to climate change. Our results highlight that the reactivity (biodegradability) of sedimentary carbon across shelf seas is highly variable with low reactivity organic matter found in the offshore region, while organic matter within inshore and coastal sediments can be highly reactive and potentially vulnerable to break‐down when disturbed. These differences in organic matter reactivity highlight the need to focus emergent management interventions that can deliver protection toward the most vulnerable organic matter stores in inshore and coastal sediments. Key Points: Within most shelf sediments organic matter (OM) is generally of low reactivity (i.e., low labile OM content) and resistant to remineralizationMuddy nearshore sediments hold large quantities of high reactivity OM which is at risk of remineralization when disturbedPolicy interventions that seek to protect reactive OM should prioritize near‐shore sediment OM over the resilient OM in many shelf seas [ABSTRACT FROM AUTHOR]

The latest IPCC report foreshadows a far gloomier picture of climate change consequences than previously held by demonstrating how avoiding environmental damage requires transforming the world economy at a speed and scale that has "no documented historic precedent." One of the options to address climate change is adoption of mitigation strategies to reduce carbon emissions on national, sectoral, and corporate levels. This research analyzes mitigation responses by organizations facing institutional and stakeholder pressures while dealing with the risk and opportunities presented by climate change. Our research indicates that different types of institutional pressures—coercive, normative, and mimetic—lead to different and, in certain situations, more active responses from companies. We find that coercive pressures are about equal or more effective than normative or mimetic pressures for adoption of mitigation strategies. [ABSTRACT FROM AUTHOR]

SUMMARY: Root architecture can be targeted in breeding programs to develop crops with better capture of water and nutrients. In rich nations, such crops would reduce production costs and environmental pollution and, in developing nations, they would improve food security and economic development. Crops with deeper roots would have better climate resilience while also sequestering atmospheric CO2. Deeper rooting, which improves water and N capture, is facilitated by steeper root growth angles, fewer axial roots, reduced lateral branching, and anatomical phenotypes that reduce the metabolic cost of root tissue. Mechanical impedance, hypoxia, and Al toxicity are constraints to subsoil exploration. To improve topsoil foraging for P, K, and other shallow resources, shallower root growth angles, more axial roots, and greater lateral branching are beneficial, as are metabolically cheap roots. In high‐input systems, parsimonious root phenotypes that focus on water capture may be advantageous. The growing prevalence of Conservation Agriculture is shifting the mechanical impedance characteristics of cultivated soils in ways that may favor plastic root phenotypes capable of exploiting low resistance pathways to the subsoil. Root ideotypes for many low‐input systems would not be optimized for any one function, but would be resilient against an array of biotic and abiotic challenges. Root hairs, reduced metabolic cost, and developmental regulation of plasticity may be useful in all environments. The fitness landscape of integrated root phenotypes is large and complex, and hence will benefit from in silico tools. Understanding and harnessing root architecture for crop improvement is a transdisciplinary opportunity to address global challenges. Significance Statement: Root architecture can be harnessed to develop crops with improved climate resilience and reduced input requirements, thereby improving global food security, agricultural sustainability, and climate change mitigation. Understanding and harnessing root architecture for crop improvement is a transdisciplinary opportunity to address global challenges. [ABSTRACT FROM AUTHOR]

Bioenergy has been identified as a key component of climate change mitigation. Therefore, quantifying the net carbon balance of bioenergy feedstocks is crucial for accurate projections of climate mitigation benefits. Switchgrass (Panicum virgatum) has many characteristics of an ideal bioenergy crop with high yields, low maintenance, and deep roots with potential for belowground carbon sequestration. However, the assessments of net annual carbon exchange between switchgrass fields and the atmosphere are rare. Here we present observations of net carbon fluxes in a minimally managed switchgrass field in Virginia (Ameriflux site US‐SB2) over 5 years (3–7 years since establishment). Average annual net ecosystem exchange (NEE) of carbon was near zero (60 g C m−2 year−1) but the net ecosystem carbon balance that includes harvested carbon (HC) was a net source of carbon to the atmosphere (313 g C m−2 year−1). The field alternated between a large and small source of carbon annually, with the interannual variability most strongly correlated with the day of the last frost and the interaction of temperature and precipitation. Overall, the consistent source of carbon to the atmosphere at US‐SB2 differs substantially from other eddy covariance studies that report switchgrass fields to be either neutral or a sink of carbon when accounting for both NEE and HC. This study illustrates that predictions of net carbon climate benefits from bioenergy crops cannot assume that the ecosystem will be a net sink of carbon from the atmosphere. Background climate, management, and land‐use history may determine whether widespread deployment of switchgrass as a bioenergy feedstock results in realized climate change mitigation. [ABSTRACT FROM AUTHOR]

Concern about climate change has increased the pressure on firms to be accountable for social impact and to report on environmental, social and governance (ESG) performance. Focusing on the view that sustainability‐oriented firms are likely to consider wider stakeholder interests and pursue high financial reporting integrity, this paper examines the association between carbon assurance and earnings management. Using a sample of firms listed on the New York Stock Exchange, we find voluntary adoption of carbon assurance (level), carbon disclosure and gender diverse boards are negatively associated with earnings management. Additional tests using different components of carbon assurance (percent and verification) confirm our main results. Our results suggest that firms that voluntarily invest in carbon assurance, carbon disclosure and gender diverse boards are less likely to engage in earnings management and thus have higher reporting integrity. This aligns with the view that firms' ethical concerns translate into higher quality reporting. [ABSTRACT FROM AUTHOR]

To increase the annual uptake of CO2 as well as the long‐term storage of carbon (C) in forests, the Norwegian government consider large‐scale replacements of native, deciduous forests with faster‐growing species like Norway spruce. To assess the effects of tree species change on ecosystem C and nitrogen (N) stocks and soil chemistry, we used a paired plot approach including stands of native downy birch and planted 45‐ to 60‐yr‐old Norway spruce. The birch stands were used as reference for the assessment of differences following the tree species change. We found significantly higher C and N stocks in living tree biomass in the spruce stands, whereas no significant differences were found for dead wood. The cover of understory species groups, and the C and N stocks of the aboveground understory vegetation were significantly higher in the birch stands. The tree species change did not affect the soil organic carbon (SOC) stock down to 1 m soil depth; however, the significantly higher stock in the forest floor of the spruce stands suggested a re‐distribution of SOC within the profile. There was a significant positive correlation between the SOC stock down to 30 cm soil depth and the total ecosystem C stock for the birch stands, and a negative correlation for the spruce stands. Significant effects of tree species change were found for C and N concentrations, C/N, exchangeable acidity, base saturation, and exchangeable Ca, K, Mg, Na, S, and Fe in the organic horizon or the upper mineral soil layer. The total ecosystem C stock ranged between 197 and 277 Mg/ha for the birch stands, and 297 and 387 Mg/ha for the spruce stands. The ecosystem C accumulation varied between 32 and 142 Mg/ha over the past 45–60 yr, whereas the net ecosystem C capture was considerably lower and potentially negative. Our results suggest that the potential to meet the governments' targets to increase C sequestration depend on the C debt incurred from the removed birch stands, the rotation length, and potentially also the susceptibility of the different stand types to future risk factors related to climate change. [ABSTRACT FROM AUTHOR]

As part of an integrated energy and climate system, biomass production for bioenergy based on the tropical perennial C4 grass energycane can both offset fossil fuels and store soil carbon (C). We measured energycane yields, root biomass, soil C pools, and soil C stocks in a 4 year field trial and modeled C flow from plants to soils in the surface layer of no‐till energycane planted after more than a century of intensive sugarcane agriculture. Aboveground yields ranged from 16.7 to 19.0 Mg C/ha over the 4 year trial. Although total C stocks did not significantly differ in the surface layer (approx. 0–20 cm) during the study, C in free and occluded light fractions decreased, whereas C in the mineral‐rich dense fraction increased over 4 years. Belowground system inputs, estimated from measurements and informed by convergence in the final soil fraction model, were set to 2.5 Mg C ha−1 year−1. With this input value, we estimated that surface soils retained photosynthetically fixed C predominantly within the mineral‐associated organic matter pool for a mean and median transit time of 177 and 110 years, respectively. Although we did not model C flow to deep soil layers (approx. 0–100 cm), observed C accumulation (11.4 Mg C ha−1 year−1) and root growth down to 120 cm suggest that soil processes and resulting C sequestration at the surface are likely to persist deeper into the soil profile. Energycane, as a strong candidate for climate change mitigation and land degradation remediation, showed high biomass yields and allocation of resources to roots, with sequestered soil C expected to persist for over a century. [ABSTRACT FROM AUTHOR]

Uncertainty remains about whether current rates of forest carbon uptake will be maintained with on-going climate change and increasing rates of disturbance. The potential exists for climate and disturbance to exceed the physiological tolerances of certain tree species and push forest ecosystems to a point where they become C sources. Thus, a diversity of tree species with a range of physiological tolerances could provide adaptive capacity and potentially sustain a C sink despite adverse abiotic influences. The fire-prone pine forests of the southeastern USA have been impacted by a combination of land use and fire exclusion, which has altered the demographics and composition of these historically diverse forests. We sought to quantify how prescribed fire and planting of climate-resilient tree species would alter forest carbon dynamics under projected climate change at Fort Benning, Georgia. This landscape is comprised of a diversity of forest types with a range of land-use histories and is heavily managed to meet military training objectives and federally listed species habitat requirements. We used a simulation approach to determine species-specific growth responses to projected climate and develop two management scenarios: no-management and prescribed fire coupled with planting. We ran landscape simulations of these two management scenarios under climate projections from ten global climate models to quantify how active management would alter forest carbon dynamics as a function of changing climate and wildfire. We found that the prescribed fire and plant scenario increased total ecosystem carbon (TEC) over our no-management scenario by over 20 Mg C/m² by late century. Despite the differences in TEC, differences in net ecosystem exchange were not realized over the entire simulation. The primary drivers of TEC differences were sustained carbon uptake and lower carbon loss to wildfire in the prescribed fire and plant scenario. Our results demonstrate that under projected climate, managing to reduce the impacts of fire and planting climate-adapted species can increase the mitigation potential of these forests. [ABSTRACT FROM AUTHOR]

Recent studies have introduced the metric GWP bio, an indicator of the potential global warming impact of CO2 emissions from biofuels. When a time horizon of 100 years was applied, the studies found the GWP bio of bioenergy from slow-growing forests to be significantly lower than the traditionally calculated GWP of CO2 from fossil fuels. This result means that bioenergy is an attractive energy source from a climate mitigation perspective. The present paper provides an improved method for quantifying GWP bio. The method is based on a model of a forest stand that includes basic dynamics and interactions of the forest's multiple carbon pools, including harvest residues, other dead organic matter, and soil carbon. Moreover, the baseline scenario (with no harvest) takes into account that a mature stand will usually continue to capture carbon if not harvested. With these methodological adjustments, the resulting GWP bio estimates are found to be two to three times as high as the estimates of GWP bio found in other studies, and also significantly higher than the GWP of fossil CO2, when a 100-year time horizon is applied. Hence, the climate impact per unit of CO2 emitted seems to be even higher for the combustion of slow-growing biomass than for the combustion of fossil carbon in a 100-year time frame. [ABSTRACT FROM AUTHOR]

The absence of boreal forests from global policy agendas on sustainable development and climate change mitigation represents a massive missed opportunity for environmental protection. The boreal zone contains some of the world's largest pools of terrestrial carbon that, if not safeguarded from a conversion to a net source of greenhouse gases, could seriously exacerbate global climate change. At the same time, boreal countries have a strong tradition of forest management-expertise that could be effectively leveraged toward global and national carbon mitigation targets and sustainable development. Current obstacles against such contributions include weak incentives for carbon sequestration and a reluctance to embrace change by forest managers and policy makers. We discuss possible solutions to overcome these obstacles, including the improvement of ineffective incentives, the development of alternative forest management strategies, and the need to maintain ecosystem resilience through the pursuit of policy and management options. [ABSTRACT FROM AUTHOR]

British Columbia ( BC) forests are estimated to have become a net carbon source in recent years due to tree death and decay caused primarily by mountain pine beetle ( MPB) and related post-harvest slash burning practices. BC forest biomass has also become a major source of wood pellets, exported primarily for bioenergy to Europe, although the sustainability and net carbon emissions of forest bioenergy in general are the subject of current debate. We simulated the temporal carbon balance of BC wood pellets against different reference scenarios for forests affected by MPB in the interior BC timber harvesting area using the Carbon Budget Model of the Canadian Forest Sector ( CBM- CFS3). We evaluated the carbon dynamics for different insect-mortality levels, at the stand- and landscape level, taking into account carbon storage in the ecosystem, wood products and fossil fuel displacement. Our results indicate that current harvesting practices, in which slash is burnt and only sawdust used for pellet production, require between 20-25 years for beetle-impacted pine and 37-39 years for spruce-dominated systems to reach pre-harvest carbon levels (i.e. break-even) at the stand-level. Using pellets made from logging slash to replace coal creates immediate net carbon benefits to the atmosphere of 17-21 tonnes C ha−1, shortening these break-even times by 9-20 years and resulting in an instant carbon break-even level on stands most severely impacted by the beetle. Harvesting pine dominated sites for timber while using slash for bioenergy was also found to be more carbon beneficial than a protection reference scenario on both stand- and landscape level. However, harvesting stands exclusively for bioenergy resulted in a net carbon source unless the system contained a high proportion of dead trees (>85%). Systems with higher proportions of living trees provide a greater climate change mitigation if used for long lived wood products. [ABSTRACT FROM AUTHOR]

Despite the passing of the carbon price legislation, implementation of climate policy must confront a number of challenges. These include the uncertain nature of benefits from the policy, uncertainty surrounding the cost of abatement within Australia, uncertainties about international action and challenges in the interaction between policy instruments (for example, between the carbon price and large subsidies to renewable energy). Each of these issues implies a substantial empirical challenge for the Australian Government and the independent agencies charged with implementation. Effort should be focused on increasing the knowledge base, rather than relying on simplified scenarios from a narrow range of economic models. [ABSTRACT FROM AUTHOR]

The implications of Australia's unilateral carbon-pricing plan for its energy-intensive, trade-exposed industries are analysed. While a priori arguments for protecting such industries make good theoretical sense, empirically significant levels of support for such protection centre on the non-ferrous metal industry alone. [ABSTRACT FROM AUTHOR]