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Tropical secondary forests sequester carbon up to 20 times faster than old-growth forests. This rate does not capture spatial regrowth patterns due to environmental and disturbance drivers. Here we quantify the influence of such drivers on the rate and spatial patterns of regrowth in the Brazilian Amazon using satellite data. Carbon sequestration rates of young secondary forests (<20 years) in the west are ~60% higher (3.0 ± 1.0 Mg C ha -1  yr -1 ) compared to those in the east (1.3 ± 0.3 Mg C ha -1  yr -1 ). Disturbances reduce regrowth rates by 8-55%. The 2017 secondary forest carbon stock, of 294 Tg C, could be 8% higher by avoiding fires and repeated deforestation. Maintaining the 2017 secondary forest area has the potential to accumulate ~19.0 Tg C yr -1 until 2030, contributing ~5.5% to Brazil's 2030 net emissions reduction target. Implementing legal mechanisms to protect and expand secondary forests whilst supporting old-growth conservation is, therefore, key to realising their potential as a nature-based climate solution.

The globally important carbon sink of intact, old-growth tropical humid forests is declining because of climate change, deforestation and degradation from fire and logging 1-3 . Recovering tropical secondary and degraded forests now cover about 10% of the tropical forest area 4 , but how much carbon they accumulate remains uncertain. Here we quantify the aboveground carbon (AGC) sink of recovering forests across three main continuous tropical humid regions: the Amazon, Borneo and Central Africa 5,6 . On the basis of satellite data products 4,7 , our analysis encompasses the heterogeneous spatial and temporal patterns of growth in degraded and secondary forests, influenced by key environmental and anthropogenic drivers. In the first 20 years of recovery, regrowth rates in Borneo were up to 45% and 58% higher than in Central Africa and the Amazon, respectively. This is due to variables such as temperature, water deficit and disturbance regimes. We find that regrowing degraded and secondary forests accumulated 107 Tg C year -1 (90-130 Tg C year -1 ) between 1984 and 2018, counterbalancing 26% (21-34%) of carbon emissions from humid tropical forest loss during the same period. Protecting old-growth forests is therefore a priority. Furthermore, we estimate that conserving recovering degraded and secondary forests can have a feasible future carbon sink potential of 53 Tg C year -1 (44-62 Tg C year -1 ) across the main tropical regions studied., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Structurally intact tropical forests sequestered about half of the global terrestrial carbon uptake over the 1990s and early 2000s, removing about 15 per cent of anthropogenic carbon dioxide emissions 1-3 . Climate-driven vegetation models typically predict that this tropical forest 'carbon sink' will continue for decades 4,5 . Here we assess trends in the carbon sink using 244 structurally intact African tropical forests spanning 11 countries, compare them with 321 published plots from Amazonia and investigate the underlying drivers of the trends. The carbon sink in live aboveground biomass in intact African tropical forests has been stable for the three decades to 2015, at 0.66 tonnes of carbon per hectare per year (95 per cent confidence interval 0.53-0.79), in contrast to the long-term decline in Amazonian forests 6 . Therefore the carbon sink responses of Earth's two largest expanses of tropical forest have diverged. The difference is largely driven by carbon losses from tree mortality, with no detectable multi-decadal trend in Africa and a long-term increase in Amazonia. Both continents show increasing tree growth, consistent with the expected net effect of rising atmospheric carbon dioxide and air temperature 7-9 . Despite the past stability of the African carbon sink, our most intensively monitored plots suggest a post-2010 increase in carbon losses, delayed compared to Amazonia, indicating asynchronous carbon sink saturation on the two continents. A statistical model including carbon dioxide, temperature, drought and forest dynamics accounts for the observed trends and indicates a long-term future decline in the African sink, whereas the Amazonian sink continues to weaken rapidly. Overall, the uptake of carbon into Earth's intact tropical forests peaked in the 1990s. Given that the global terrestrial carbon sink is increasing in size, independent observations indicating greater recent carbon uptake into the Northern Hemisphere landmass 10 reinforce our conclusion that the intact tropical forest carbon sink has already peaked. This saturation and ongoing decline of the tropical forest carbon sink has consequences for policies intended to stabilize Earth's climate.

Countries have pledged to different national and international environmental agreements, most prominently the climate change mitigation targets of the Paris Agreement. Accounting for carbon stocks and flows (fluxes) is essential for countries that have recently adopted the United Nations System of Environmental-Economic Accounting - ecosystem accounting framework (UNSEEA) as a global statistical standard. In this paper, we analyze how spatial carbon fluxes can be used in support of the UNSEEA carbon accounts in five case countries with available in-situ data. Using global multi-date biomass map products and other remotely sensed data, we mapped the 2010–2018 carbon fluxes in Brazil, the Netherlands, the Philippines, Sweden and the USA using National Forest Inventory (NFI) and local biomass maps from airborne LiDAR as reference data. We identified areas that are unsupported by the reference data within environmental feature space (6–47% of vegetated country area); cross-validated an ensemble machine learning (RMSE=9–39 Mg C ha - 1 and R 2 =0.16–0.71) used to map carbon fluxes with prediction intervals; and assessed spatially correlated residuals (<5 km) before aggregating carbon fluxes from 1-ha pixels to UNSEEA forest classes. The resulting carbon accounting tables revealed the net carbon sequestration in natural broadleaved forests. Both in plantations and in other woody vegetation ecosystems, emissions exceeded sequestration. Overall, our estimates align with FAO-Forest Resource Assessment and national studies with the largest deviations in Brazil and USA. These two countries used highly clustered reference data, where clustering caused uncertainty given the need to extrapolate to under-sampled areas. We finally provide recommendations to mitigate the effect of under-sampling and to better account for the uncertainties once carbon stocks and flows need to be aggregated in relatively smaller countries. These actions are timely given the global initiatives that aim to upscale UNSEEA carbon accounting. [ABSTRACT FROM AUTHOR]

This study looked at the potential of thermal comfort provided to animals by four different Brazilian savanna (Cerrado) native trees, as well as their potential for carbon sink. The evaluations were carried out during the summer of 2020, which consisted of the collection of microclimate variables. The Mean Radiant Temperature (TMR, °C) was derived from the shaded and unshaded areas under the trees, and from that, the Radiant Heat Load (RHL, W m -2 ) was calculated as an index of thermal comfort. Solar radiation was estimated considering the sum of the direct, diffuse, and reflected components (W m -2 ), and carbon stock from trees biomass for CO 2 sequestration was estimated from an allometric model applied to the native Cerrado tree species. The shade of the native trees reduced the meteorological variables such as dry bulb and black globe temperatures, to values considered adequate for the thermal comfort of animals, with an average reduction respectively equal to 1.3 °C and 6.4 °C. This represents a significant difference compared to the unshaded area as well as among tree species (P < 0.05), reflecting in lower values of TMR and RHL in the shaded area provided by each species. Carbon sequestration individually estimated by each native tree species was on average 8.85 Mg per tree. These results demonstrate the great potential for native tree species in the Cerrado biome to be used in agroforestry systems to provide higher levels of thermal comfort to animals and to combat climate change through their aptitude of CO 2 sink., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Many nations have pledged to reach carbon neutrality by 2050. Embarking on the decarbonization journey, they posited geological carbon storage (GCS) as a pivotal technology within the carbon capture, utilization, and storage (CCUS) framework. The CCUS chain operates to reduce "hard-to-abate" emissions at key sectors by capturing carbon dioxide (CO 2), reusing it, transporting it, or disposing of it via injection into underground geological formations for permanent storage. Despite the global success of GCS ventures, mainly driven by the oil and gas industry, GCS initiatives are still in their early stages in several developing countries. In Brazil, for instance, a full setup covering precise storage capacity databases, potential CCUS clusters, national regulatory structure, and auxiliary computer-aided engineering is underway. Intended to push the frontier in the latter subject, this paper introduces mathematical models for qualifying underground CO 2 storage sites. Our research explores a family of multivariate functionals endowed with underlying reservoir features and distinct weighting functions, thus envisioning two primary objectives. Firstly, it clarifies non-linear interactions between rock and fluid properties using quality indicators. Secondly, it evaluates geographical regions considering structural traps/caprocks settings. Backed by the Matlab Reservoir Simulation Toolbox (MRST) capabilities, the methodology is a subsidiary resource for identifying suitable injection and storage sites. A case study using the UNISIM-I-D model generated dozens of volumetric quality maps that point to unique potential storage sites. Numerical simulation experiments of injection comparing legacy and novel wells reveal storage surpluses improved by up to 50%. The paper seeks to establish foundational knowledge in GCS efficiency for general underground settings. One expects that these outcomes leverage well-repurposing perspectives and stimulate field appraisal actions to scale up GCS projects both in Brazil and worldwide. • Introduction of a family of mathematical functionals for site qualification. • Trap analysis and supercritical gas injection over a Brazilian offshore reservoir model. • Comparison of storage surplus in theoretically-proposed and legacy well locations. [ABSTRACT FROM AUTHOR]

In this study, projections and current status of municipal solid waste generation worldwide and its collection, final destination, and waste-to-energy technologies are reviewed. Firstly, an overview of waste generation worldwide is presented comparing income levels and the material composition of residues in several regions. This paper focused on contrasting Brazil and Portugal in terms of waste production and its management from generation to disposal or treatment. Furthermore, it is presented a summary of leading waste-to-energy technologies such as incineration, anaerobic digestion, gasification, pyrolysis, co-combustion, co-gasification, among others. Technical aspects of these thermo-chemical, biological, and physic-chemical processes for the production of biofuels such as biogas, syngas, biodiesel, and hydrogen-enriched gases are presented. Additionally, current aspects of the waste-to-energy market are exposed regarding the major players, investments, and expectations for the future of this activity with the elaboration of SWOT analyses. Finally, a review of greenhouse gases emissions worldwide is presented, specifically from Brazil and Portugal, as well as some consequences of these pollutant gases on the society and the environment and which are the main technologies for carbon dioxide capturing and sequestration as promising solutions for lower pollutant gases concentration in the atmosphere. This review paper aims to provide information for the management of municipal solid waste in Brazil and Portugal considering the mutual objective of meeting sustainable development goals. [ABSTRACT FROM AUTHOR]

Cropland expansion threatens biodiversity by driving habitat loss and impacts carbon storage through loss of biomass and soil carbon (C). There is a growing concern land-use change (LUC) to cropland will result in a loss of ecosystem function and various ecosystem services essential for human health and well-being. This paper examines projections of future cropland expansion from an integrated assessment model IMAGE 3.0 under a "business as usual" scenario and the direct impact on both biodiversity and C storage. By focusing on biodiversity hotspots and Alliance for Zero Extinction (AZE) sites, loss of habitat as well as potential impacts on endangered and critically endangered species are explored. With regards to C storage, the impact on both soil and vegetation standing C stocks are examined. We show that if projected trends are realized, there are likely to be severe consequences for these resources. Substantial loss of habitat in biodiversity hotspots such as Indo-Burma, and the Philippians is expected as well as 50% of species in AZE sites losing part of their last remaining habitat. An estimated 13.7% of vegetation standing C stocks and 4.6% of soil C stocks are also projected to be lost in areas affected with Brazil and Mexico being identified as priorities in terms of both biodiversity and C losses from cropland expansion. Changes in policy to regulate projected cropland expansion, and increased measures to protect natural resources, are highly likely to be required to prevent these biodiversity and C losses in the future., (© 2018 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.)

It is well recognized that commercial beef cattle production systems have a major impact on climate change, mainly due to the emission of enteric methane (CH4). The objective of this research was to evaluate if integrating animal + pasture + timber production in silvopastoral systems (SPS) would help neutralize the impact of enteric CH4 emission by facilitating carbon storage as soil organic carbon (SOC). This paper reports a study conducted in Brazil with a herd of 150 cows in 100 ha of Urochloa brizantha with Eucalyptus urograndis, on four tree configurations: SPS 1-clone GG-100 at 2 × 3 × 15 m spacing; SPS 2-clone i-144 at 2 × 3 × 15 m; SPS 3-clone GG-100 at 3 × 15 m; and SPS 4-clone i-144 at 3 × 15 m. Based on data collected through eight consecutive years, the gas balance was estimated. For all SPS treatments average, the carbon dioxide equivalent (CO2e) of additional C stock exceeded the emissions. Considering only C sequestration from trees, the average CO2e sequestration was − 26.27 Mg·CO2e ha−1, while the average emissions of CO2 e was 23.54 Mg·CO2e ha−1 for enteric CH4 + pasture + tree, giving a net balance of − 2.73 Mg·CO2e ha−1. The "loss" of CO2e analyzed was compensated by the soil C sequestration in long-lived SOC pools, enhancing the resilience of farming systems by increasing soil organic matter and soil fertility capacity, mitigating greenhouse gas emissions, therefore, providing benefits in livestock production and for environmental remediation. [ABSTRACT FROM AUTHOR]

Brazil is recognized for possessing a low carbon-intensive energy matrix, with most of its power being generated from hydroelectricity. Its greenhouse gas emissions profile is dominated by deforestation and land-use change. Despite this characteristic, the country has been committed to the development of carbon capture and geological storage (CCS) research since this technology started to be recognized as a relevant solution for greenhouse gas emission reductions. This development has gained attention recently owing to the beginning of the production of pre-salt reservoirs, which may contain significant amounts of CO2 in the produced fluids. The work has been carried out mostly through the efforts of the academia and industrial enterprises. This paper presents a summary and a brief description of the recent activities being carried out by these sectors, aiming to develop and promote CCS in Brazil. [ABSTRACT FROM AUTHOR]

Enhanced silicate rock weathering for long-term carbon dioxide sequestration has considerable potential, but depends on the availability of suitable rocks coupled with proximity to suitable locations for field application. In this paper, we investigate the established mining industry that extracts basaltic rocks for construction from the Paraná Basin, Sao Paulo State, Brazil. Through a Life Cycle Assessment, we determine the balance of carbon dioxide emissions involved in the use of this material, the relative contribution of soil carbonation and enhanced weathering, and the potential carbon dioxide removal of Sao Paulo agricultural land through enhanced weathering of basalt rock. Our results show that enhanced weathering and carbonation respectively emit around 75 and 135 kg carbon dioxide equivalent per tonne of carbon dioxide equivalent removed (considering a quarry to field distance of 65 km). We underline transportation as the principal process negatively affecting the practice and uncover a limiting road travel distance from the quarry to the field of 540 ± 65 km for carbonation and 990 ± 116 km for enhanced weathering, above which the emissions offset the potential capture. Regarding Sao Paulo State, the application of crushed basalt at 1 t/ha to all of the State's 12 million hectares of agricultural land could capture around 1.3 to 2.4 Mt carbon dioxide equivalent through carbonation and enhanced weathering, respectively. This study suggests a lower sequestration estimate than previous studies and emphasizes the need to consider all process stages through a Life Cycle Assessment methodology, to provide more reliable estimates of the sequestration potential of greenhouse gas removal technologies. • First assessment of the burdens associated with enhanced weathering and carbonation. • Transportation of the material greatly impacts the sequestration potential. • The quarry to field offsetting distance is 550 ± 65 km for carbonation. • On Sao Paulo average, the practice emit 0.110 kg CO 2 eq per kg of CO 2 removed. • The setup burdens of the practice reduce previous sequestration estimates. [ABSTRACT FROM AUTHOR]

Due to its low global share of direct energy consumption and greenhouse gas emissions (1–2%), the implications of technological transitions in the agricultural and forestry sector on the energy system have been overlooked. This paper introduces the Agriculture and Land Use Sector module part of the ModUlar energy System Environment (MUSE), a novel energy system simulation model. The study presents a generalisable method that enables energy modellers to characterise agricultural technologies within an energy system modelling framework. Different mechanisation processes were characterised to simulate intensification/extensification transitions in the sector and its wider implications in the energy and land use system aiming at providing reliable non-energy outputs similarly to those found in dedicated land use models. Additionally, a forest growth model has been integrated to explore the role of reforestation alongside decarbonisation measures in the energy system in achieving carbon mitigation pathways. To illustrate the model's capabilities, Brazil is used as case study. Outputs suggest that by 2030 under a 2 °C mitigation scenario, most of Brazil agricultural production would move from 'transitional' to 'modern' practices, improving productivity and reducing deforestation rates, at the expense of higher energy and fertiliser demand. By mid-century Brazil has the potential to liberate around 24.4 Mha of agricultural land, where large-scale reforestation could have the capacity to sequester around 5.6 GtCO 2 , alleviating mitigation efforts in the energy system, especially reducing carbon capture and storage technology investments in the industry and power sector. • A novel energy-oriented agriculture and land use systems model has been developed. • Mechanisation levels are characterised using cluster analysis and linear optimisation. • Role of reforestation alongside measures in the energy sector in Brazil are studied. • By 2050, modern mechanisation could represent 54–63% of agricultural production. • Brazil has the potential to sequester around 5.6 GtCO 2 through reforestation. [ABSTRACT FROM AUTHOR]

The present paper reports the assessment of the vegetation occupancy rate of the roadside, through analysis of aerial photographs. Using such value the potential of these areas to be employed as carbon (C) sinks was also assessed. Moreover, for the areas suitable for afforestation, the potential for carbon sequestration was estimated considering different species of vegetation, both native (scenario 1) and exotic (formed by Pinus sp. and Eucalyptus sp. - scenario 2). The study was carried out through GIS techniques and two regions were considered. A set of equations was used to estimate the rate of occupancy over the study areas, as well as amounts of fixed C under the above scenarios. The average occupancy rate was 0.06%. The simulation showed a higher potential for C sequestration in scenario 2, being the estimated amounts of CO2 sequestered from the atmosphere per km of roadside: 131 tons of CO2 km-1 of highway to native species and 655 tons of CO2 km-1 of highway for exotic species (over period of 10 years for both estimates). If we consider the whole road network of the São Paulo State (approximately 190 000 km) and that a considerable part of this road work is suitable to receive this kind of service, it is possible to predict the very high potential for C sequestration if managers and planners consider roadside as area for afforestation. [ABSTRACT FROM AUTHOR]

• The questionnaire assessed environmental awareness and knowledge about CCS technology. • The interviews were conducted using a face-to-face approach. • A structured research was employed using an ordinal qualitative scale. • Respondents were aware of the climate change. • Climate change mitigation actions are not a priority for respondents. Carbon Capture and Storage (CCS) is considered an important option to mitigate climate change. However, the success of the new technology does not only depend on engineering practices and techniques but also involves social, political, and economic factors, as well as public acceptance. The discussion about CCS in Brazil is recent and few papers addressing Brazilian public perception and engagement with CCS were found. In this sense, this paper aims to analyze the environmental awareness about climate change and the citizens' perception of CCS technology. A public perception survey was conducted with 800 people in two Brazilian cities. Descriptive statistical techniques combined with hypothesis tests were performed to depict the results and to verify associations between different demographic groups to climate change issues and support for the development of CCS technology in Brazil. The results show that the public is aware of climate change and its consequences. However, despite public support for governmental development and investments in CCS technology, investments to mitigate climate change are not a priority for the population. Only 2% and 5% of interviewed citizens in the cities of São Mateus and Vitória, respectively, considered investments in climate change mitigation as a priority. More than 70% of respondents considered that other social elements, as health, public safety, and job creation, should be prioritized by the Brazilian government. The results suggest that the population needs more information about CCS technology and its impacts. [Display omitted] [ABSTRACT FROM AUTHOR]

• BECCS assessment of a power system based on biomass gasification (BIG-CC), integrated into a sugarcane plant. • CO 2 capture by the pre-combustion route has less impact on the sale of surplus electricity. • The CO 2 mitigation cost was estimated at 60 €/tCO 2 for pre-combustion and 52 €/tCO 2 for post-combustion. • The feasibility of CO 2 capture is impacted by the scale and cost of electricity generation. • Conventional cogeneration systems (CEST) are suggested for the first BECCS units. In order to make feasible the efforts that would limit the rise of Earth's temperature to no more than 2 °C, profound changes are required in the energy systems. In this sense, BECCS are considered instrumental to attain possible negative emissions. This draws attention to the sugarcane industry in Brazil, where it is possible to produce fuel ethanol at a relative low cost and a large amount of relatively cheap biomass is available. This paper is part of a research that aims to study the combined production of liquid fuels and electricity, using sustainable sources of biomass and maximizing carbon capture. Two cases related to an innovative technology were evaluated and in both the capture is based on amine technology: pre-combustion capture of CO 2 from the fuel gas derived from biomass gasification, and post-combustion capture from gas turbine exhaust gases. Information from the scientific literature was used in modelling the systems, as well as estimating energy penalties and costs associated with capturing, transporting and storing CO 2. The results indicate technical feasibility of both capture options, but difficulties in setting the full integration of the power unit (BIG-CC) with the sugarcane mill and the CCS system, due to the high demand for thermal energy as low-pressure steam. The estimated CO 2 abatement cost is in the range 60–71 €/tCO 2 for pre-combustion capture, and 52–63 €/tCO 2 in the case of post-combustion. Feasibility results are impacted by the scale of CO 2 capture (0.82–1.44 MtCO 2 /year), particularly in the pre-combustion case, and the relatively high cost of electricity generation. [ABSTRACT FROM AUTHOR]

Bioenergy could play a major role in decarbonizing energy systems in the context of the Paris Agreement. Large‐scale bioenergy deployment could be related to sustainability issues and requires major infrastructure investments. It, therefore, needs to be studied carefully. The Bioenergy and Land Optimization Spatially Explicit Model (BLOEM) presented here allows for assessing different bioenergy pathways while encompassing various dimensions that influence their optimal deployment. In this study, BLOEM was applied to the Brazilian context by coupling it with the Brazilian Land Use and Energy Systems (BLUES) model. This allowed investigating the most cost‐effective ways of attending future bioenergy supply projections and studying the role of recovered degraded pasture lands in improving land availability in a sustainable and competitive manner. The results show optimizing for limiting deforestation and minimizing logistics costs results in different outcomes. It also indicates that recovering degraded pasture lands is attractive from both logistics and climate perspectives. The systemic approach of BLOEM provides spatial results, highlighting the trade‐offs between crop allocation, land use and the logistics dynamics between production, conversion, and demand, providing valuable insights for regional and national climate policy design. This makes it a useful tool for mapping sustainable bioenergy value chain pathways. [ABSTRACT FROM AUTHOR]

Despite its rich water resources, Brazil is increasingly facing extreme hydrologic events such as droughts and floods. The Sao Paulo Cantareira water supply system (CWSS) offers an opportunity to examine the potential economic benefits of nature-based solutions (NbS) to improve water security and reduce the economic cost of drought. This study explores the potential benefits under a counterfactual NbS land-use scenario compared to actual land use and assesses the economic viability of NbS investments in the CWSS. Specifically, we estimate the economic cost of the 2014–2015 drought in Sao Paulo state for the industrial and water sectors served by the CWSS. We estimate the potential avoided costs under the NbS scenario and conduct a cost–benefit analysis of the NbS scenario investments, including both water supply and carbon sequestration benefits. We estimate that the economic losses of this single drought event totaled BRL 1.6 billion. If NbS had been implemented, this cost could have been reduced by 28%. A cost–benefit analysis that includes only the water supply or both the water supply and carbon sequestration benefits indicates that the NbS scenario has a positive net present value of BRL 144 million and BRL 632 million, respectively. Thus, our results highlight the economic viability of the hypothetical NbS investment in mitigating extreme climatic events. [ABSTRACT FROM AUTHOR]

• The Technology Readiness Levels (TRL) approach is employed for estimating the maturity of CCS System. • A Technology Readiness Assessment (TRA) for a new Carbon Capture and Storage (CCS) concept using offshore salt caverns. • A concept system that allows the monetization of the separated natural gas. • A salt cavern for the storage of 1 billion Sm3 (Standard cubic meter) of a natural gas stream with high CO 2 content. This article presents a Technology Readiness Assessment (TRA) of a new concept called the Salt Cavern Hybrid Subsea Carbon Capture and Storage (CCS) System, which performs all the offshore natural gas and CO 2 separation process with subsequent storage in offshore underground salt caverns. Currently there is a demand for CCS of large quantities of CO 2 associated with CH 4 in the pre-salt offshore oil fields in Brazil. The pre-salt reservoirs have as caprock 2000 m of continuous rock salt. This hybrid system is expected to perform, at the same time, the separation between the natural gas and CO 2 , and Carbon Capture and Storage of CO 2 , allowing the monetization of the separated natural gas. The Technology Readiness Levels (TRL) approach is discussed in this paper for estimating the maturity of the CCS System. The TRL analysis concluded that no technological gaps were identified that would made the project unfeasible and the TRL level enables the project to advance to the field test stage within a reasonably short time horizon. Once implemented it could be one of the largest CCS projects in the world. Also, this paper describes the conceptual design of this hybrid system and presents the results of a TRA showing the methodology that was employed in the process, the technology critical items that were analyzed and the results obtained for each of them and the design of a salt cavern for the storage of 1 billion Sm3 (Standard cubic meter) of a natural gas stream with high CO 2 content. [ABSTRACT FROM AUTHOR]

Stabilization at concentrations consistent with keeping global warming below 2 °C above the pre-industrial level will require drastic cuts in Greenhouse Gas (GHG) emissions during the first half of the century; net negative emissions approaching 2100 are required in the vast majority of current emission scenarios. For negative emissions, the focus has been on bioenergy with carbon capture and storage (BECCS), where carbon-neutral bioenergy would be combined with additional carbon capture thus yielding emissions lower than zero. Different BECCS technologies are considered around the world and one option that deserves special attention applies CCS to ethanol production. It is currently possible to eliminate 27.7 million tonnes (Mt) of CO 2 emissions per year through capture and storage of CO 2 released during fermentation, which is part of sugar cane-based ethanol production in Brazil. Thus, BECCS could reduce the country’s emissions from energy production by roughly 5%. Such emissions are additional to those due to the substitution of biomass-based electricity for fossil-fueled power plants. This paper assesses the potential and cost effectiveness of negative emissions in the joint production system of ethanol and electricity based on sugar cane, bagasse, and other residues in Brazil. An important benefit is that CO 2 can be captured twice along the proposed BECCS supply chain (once during fermentation and once during electricity generation). This study only considers BECCS from fermentation because capturing such CO 2 is straightforward, thus potentially representing a cost-effective mitigation option for Brazil compared to other alternatives. The assessment shows that fuel prices would increase by less than 3.5% due to the adoption of BECCS from fermentation, while increasing investors’ revenues are sufficient to compensate for the investment required. With appropriate government subsidies, or by sharing BECCS costs between all car fuels and all electricity supplied by hydro and bioelectricity, the increment in ethanol and electricity prices could be less than 1% for the final consumer. Meanwhile it would supply 77.3% of all cars’ fuel (private cars) and 17.9% of all electricity in Brazil. [ABSTRACT FROM AUTHOR]

Soil and climatic conditions allied to advanced forestry technologies have enabled the development of planted forests in some regions of Brazil with some of the highest productivity rates in the world. However, the intense use of agricultural inputs and mechanization of production and wood transportation imply significant environmental impacts, such as the emission of carbon and nitrogen compounds. The purpose of this paper is to compare a model of an Integrated Crop-Livestock-Forestry System with more conventional eucalyptus forestry using a Cleaner Production approach to demonstrate the economic and environmental advantages of such a system. This is based on an environmental, energy, and economic analysis integrating Life Cycle Assessment and Cleaner Production approaches. Life Cycle Inventories consist of primary data obtained from the states of Bahia, Espírito Santo and Minas Gerais in Brazil, in partnership with Forestry Producers and a Forestry Company, which is the largest producer of hardwood pulp in the world. The inventories of conventional short-cycle eucalyptus production systems to supply the Forestry Company were quantified from seedling preparation to harvesting operations. The following production systems were evaluated: Reference system – Planting + Replanting (S1); Planting + Regrowth (S2), and Crop-Livestock-Forestry (S3). The adoption of CP measures in S3 reduced the use of inputs by 35% and increased gross revenue compared to S1. The processes that most contributed to the impact categories analyzed were soil preparation, emissions of inputs used in the field, and mechanized harvesting. However, biogenic carbon sequestration included −783 kg CO 2 eq/m3 of wood for S1. The S2 system had lower impacts compared to S1. Integrated Crop-Livestock-Forestry System - S3 showed a better environmental performance for most of the impact categories analyzed and presented a better financial return compared with S1 and S2. The implementation of the CP measures in S3 provides an immediate payback. Based on the conditions of this study, the CP strategy for silviculture is an economically viable option to increase the net CO 2 sequestration of forest production. This research intends to promote the study of eucalyptus forest production under tropical conditions, using the combined use of LCA and CP approach presented in this study from primary data. The CP and LCA integration provided methodological advances and more detailed information on the environmental performance of short-cycle eucalyptus production by identifying operational practices for the analyzed systems yielding environmental and financial gains. CP proved to be effective in providing information for decision-making at the process level without losing the broader view of the environmental performance of the analyzed product systems. [ABSTRACT FROM AUTHOR]

Forest plantations play an important role ecologically, contribute to carbon sequestration and support billions of dollars of economic activity each year through sustainable forest management and forest sector value chains. As the global demand for forest products and services increases, the marketplace is seeking more reliable data on forest plantations. Remote sensing technologies allied with machine learning, and most recently deep learning techniques, provide valuable data for inventorying forest plantations and related valuation products. In this work, deep semantic segmentation with U-net architecture was used to detect forest plantation areas using Sentinel-2 and CBERS-4A images of different areas of Brazil. First, the U-net models were built from an area of the Centre-East of Paraná State, and then the best models were tested in 3 new areas that present different characteristics. The U-net models built with Sentinel-2 images achieved promising results for areas similar to the ones used in the training set, with F1-score ranging from 0.9171 to 0.9499 and with Kappa values between 0.8712 to 0.9272, demonstrating the feasibility of deep semantic segmentation to detect forest plantations. [ABSTRACT FROM AUTHOR]

Brazil is one of the largest producers of eucalyptus that is used for manufacturing pulp and paper; this contributes directly to the issue of carbon emissions. Reforestation of eucalyptus appears as a viable alternative for mitigating these carbon emissions, leveraging their high productivity to that of other leading countries in the market, such as Finland and Sweden. This study aims to develop a model for monitoring and evaluating forest growth and quantifying wood stocks and sequestered carbon. System dynamics was used to simulate forest growth. Forest growth was modeled from eight regions with dissimilar edaphoclimatic characteristics, in the state of Minas Gerais, in Brazil. The model was sensitive enough to the characteristics of the regions, where the difference in forest stocks was 45.1% at the end of 30 years in a harvest cycle of 7 years. It was found that the typical harvest cycle in practice by leading companies did not always yield a higher sequestered CO 2 accumulated stock. By shortening the harvest cycle, it was possible to obtain a gain of up to 21.0% in the sequestered CO 2 stock. [ABSTRACT FROM AUTHOR]

Abstract: Continental shelves have the potential to remove atmospheric carbon dioxide via the biological pump, burying it in seafloor sediments. The efficiency of marine carbon sequestration changes rapidly due to variations in biological productivity, organic carbon oxidation, and burial rate. Here we present a high temporal resolution record of marine carbon sequestration changes from a western South Atlantic shelf site sensitive to Brazil Current-driven upwelling. The comparison of biological records to rare earth element (REE) patterns from authigenic oxides shows a strong relationship between higher biological productivity and stronger particle reactive element cycling (i.e. REE cycling) during rapid climate change events. This is the first evidence that authigenic oxides archive past changes in upper ocean REE cycling by the exported organic carbon. In addition, our data suggest that Brazil Current-driven upwelling varies on millennial-scales and in time with continental precipitation anomalies as registered in Brazilian speleothems during the Holocene. This indicates an ocean–atmosphere control on the biological pump, most probably related to South American monsoon system variability. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the results of the EX-Ante Carbon-balance Tool (EX-ACT) application on two rural development projects in Brazil. The analysis provides an estimate of project impact on GHG emissions and C sequestration indicating net mitigation potential: results show that the Santa Catarina Rural Competitiveness Project has the potential to mitigate 12.2Mt CO2e and the Rio de Janeiro Sustainable Rural Development Project 0.85Mt CO2e. Both projects are successful at promoting activities aimed at reducing rural poverty and also contribute to climate change mitigation, demonstrating the potential importance of sustainable agriculture (improved cropland and grassland management, expansion of agro-forestry systems and protection of forested areas) in delivering environmental services. EX-ACT has also been used as a tool to guide project developers in refining components and activities to increase project environmental benefits. Cost–benefit analysis shows that while both projects generate environmental benefits associated with climate change mitigation, the Santa Catarina Rural Competitiveness Project has significantly higher potential due to the size of the project area and the nature of activities, thus a higher likelihood of potential co-financing from climate finance sources. [Copyright &y& Elsevier]

Abstract: This paper presents an overview of the current status of the main CCS initiatives in the major emerging economies: China, India, Brazil, Mexico, Russia, and South Africa. This study first covers all six countries as a group and describes their natural resources. The second part of this study embraces each country individually and includes current initiatives and current legal and technological status of CCS. At the end, this study summarizes the main findings in the emerging economies and the potential of including CCS as part of the CDM. [Copyright &y& Elsevier]

Abstract: This paper reviews current knowledge on changes in carbon stocks upon land use conversion in the Brazilian Cerrado. First, we briefly characterize the savanna ecosystem and summarize the main published data on C stocks under natural conditions. The effects of increased land use pressure in the Cerrado and current uncertainties of estimations of changes in land cover and land use are reviewed next. Thereafter, we focus on soil organic carbon (SOC) dynamics due to changes in land use, particularly conversion to pastures and soybean-based cropping systems, and effects of management practices such as soil fertilization, crop rotations and tillage practices. Most studies considered here suggest that more intensive agriculture, which include no-till practices and the implementation of best or recommended management practices (RMP), reduces SOC losses after land use conversion from conventional tillage-based, monocropping systems; however, these studies focussed on the first 0.3m of soil, or less, and seldom considered full carbon accounting. To better estimate possible global warming mitigation with agriculture in the Cerrado more comprehensive studies are needed that analyse fluxes of the biogenic greenhouse gases (GHG; CO2, N2O and CH4) to determine the net global warming potential (GWP). Follow up studies should include the application of an integrated modelling system, comprised of a Geographic Information System (GIS) linked to dynamic modelling tools, to analyse SOC dynamics and make projections for possible changes in net C flows in the Cerrado region upon defined changes in soil use and management. [Copyright &y& Elsevier]

Abstract: Economically optimal rotations are not frequently employed in Eucalyptus plantations management despite eucalypts’ economic importance to the pulp industry. The coppice regeneration method used to manage eucalypts leads to a simultaneous optimization problem. In such cases, the manager has to simultaneously define the optimal age in each coppice rotation and the optimal number of coppice rotations for each plantation full cycle. The dynamic nature of the problem of looking for the optimal set of coppice rotations for Eucalyptus plantations obliges managers to use the dynamic programming technique. In order to evaluate the economic loss occasioned when optimal rotations are not considered, two plantations are shown, one with Eucalyptus urophylla S.T. Blake in Brazil and another with Eucalyptus globulus Labill in Spain. Different clearcut ages are established in each country, 5–9 years in Brazil, and 13–18 years in Spain. A multiple products context (wood and carbon) is considered in this paper. The results show different rotations and optimal number of coppice rotations for each site index and case considered. To repeat the seedling rotation in the following coppice rotations usually is not the best option. Besides, the optimal cycle and the land expectation value vary when carbon sequestration is evaluated for the two plantations considered. Finally, on some occasions the results are very sensitive to changes in parameters like the carbon price and discount rate. [Copyright &y& Elsevier]

Mangroves have among the highest carbon densities of any tropical forest. These 'blue carbon' ecosystems can store large amounts of carbon for long periods, and their protection reduces greenhouse gas emissions and supports climate change mitigation. Incorporating mangroves into Nationally Determined Contributions to the Paris Agreement and their valuation on carbon markets requires predicting how the management of different land‐uses can prevent future greenhouse gas emissions and increase CO2 sequestration. We integrated comprehensive global datasets for carbon stocks, mangrove distribution, deforestation rates, and land‐use change drivers into a predictive model of mangrove carbon emissions. We project emissions and foregone soil carbon sequestration potential under 'business as usual' rates of mangrove loss. Emissions from mangrove loss could reach 2391 Tg CO2 eq by the end of the century, or 3392 Tg CO2 eq when considering foregone soil carbon sequestration. The highest emissions were predicted in southeast and south Asia (West Coral Triangle, Sunda Shelf, and the Bay of Bengal) due to conversion to aquaculture or agriculture, followed by the Caribbean (Tropical Northwest Atlantic) due to clearing and erosion, and the Andaman coast (West Myanmar) and north Brazil due to erosion. Together, these six regions accounted for 90% of the total potential CO2 eq future emissions. Mangrove loss has been slowing, and global emissions could be more than halved if reduced loss rates remain in the future. Notably, the location of global emission hotspots was consistent with every dataset used to calculate deforestation rates or with alternative assumptions about carbon storage and emissions. Our results indicate the regions in need of policy actions to address emissions arising from mangrove loss and the drivers that could be managed to prevent them. [ABSTRACT FROM AUTHOR]

Cement production contributes 8–9% of all anthropogenic CO2 emissions worldwide, and further increases in the future are expected. Traditional solutions for reducing emissions, including energy efficiency, using alternative fuels, and clinker‐to‐cement ratio reduction, are insufficient to ensure the necessary mitigation. Based on the concept of material efficiency, this study identifies new alternatives for reducing CO2 emissions by adopting a set of technological solutions to increase the industrialization of cement‐based products and the use of fillers considering a cradle‐to‐use approach. Besides, increasing the filler content in mortars and plain concrete is a desirable strategy, because it increases the carbonation rate, accelerating the CO2 sequestration from the atmosphere. Based on data from the Brazilian cement industry technology roadmap, this study quantitatively evaluates, up to 2050, the CO2 mitigation potential and the reduction of cement consumption for each adopted technological solution. The marginal abatement costs are also included to quantify each considered solution's cost‐effectiveness and compared with alternatives like carbon capture and storage. The results show that increasing the cement use efficiency enables CO2 emissions reduction by up to 45% by 2050, with a cost of USD –1.36 for each avoided metric ton of CO2, while accelerating the mortar carbonation rate. This article met the requirements for a gold–gold JIE data openness badge described in http://jie.click/badges. [ABSTRACT FROM AUTHOR]

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The adoption of no‐till (NT) has been proposed to recover soil organic carbon (SOC), which will aid the mitigation of climate change. However, studies have questioned the potential of NT soils to deliver SOC sequestration and sustain crop yields. No‐till experiments are relatively recent (<50 years) and very few studies were able to assess SOC dynamics in high‐yield agroecosystems. We used the DSSAT‐CENTURY model to predict long‐term SOC (0–30 cm) using datasets from two experiments assessing tillage and nitrogen (N) sources in a Mollisol from the midwest United States (28 years) and tillage and crop rotations in an Oxisol from southern Brazil (33 years). The conversion of prairie and grassland soils to conventional agriculture decreased SOC by 61 and 12% in the Mollisol and Oxisol, respectively. Soil organic C accrual in NT soils was >0.5 Mg C ha−1 year−1 under medium‐low‐yield maize in the Mollisol and negligible in the Oxisol under soybean/wheat rotation. Organic fertilization and crop rotation increased SOC accrual at both sites. Simulated SOC had good agreement with observations for NT soils but overestimated SOC in tilled soils. The model's parameters were then modified for tilled soils. Long‐term simulations (100 years) revealed that SOC accrual in NT soils (0–15 cm) is partially offset by losses at 15–30 cm under low C inputs. Simulations with best crop management practices (BP; irrigation, high‐yield cultivars, higher plant density and improved N fertilization) augmented C inputs and SOC stocks, ultimately recovering SOC to the levels of prairie soils. Our results suggest that the adoption of NT, recycling of organic fertilizers and the use of BP should be further promoted for recovery and permanence of SOC in agricultural soils. Highlights: Studies have questioned the potential of conservation agriculture (CA) to deliver SOC sequestration and sustain crop yields.We used the DSSAT‐CENTURY model to simulate SOC dynamics in temperate and subtropical soils.No‐till under moderate C/N inputs recovered topsoil SOC, but subsurface losses offset SOC accrual.Use of CA, organic amendments and best practice crop management (BP) is crucial for long‐term SOC storage and permanence. [ABSTRACT FROM AUTHOR]

The Nationally Determined Contributions (NDCs) to the Paris Agreement (PA) submitted so far do not put the world on track to meet the targets of the Agreement and by 2020 countries should ratchet up ambition in the new round of NDCs. Brazil's NDC to the PA received mixed reviews and has been rated as "medium" ambition. We use the Brazil Land Use and Energy System (BLUES) model to explore low-emission scenarios for Brazil for the 2010–2050 period that cost-effectively raise ambition to levels consistent with PA targets. Our results reinforce the fundamental role of the agriculture, forest, and land use (AFOLU) sectors and explore inter-sectoral linkages to power generation and transportation. We identify transportation as a prime candidate for decarbonization, leveraging Brazil's already low-carbon electricity production and its high bioenergy production. Results indicate the most important mitigation measures are electrification of the light-duty vehicle (LDV) fleet for passenger transportation, biodiesel and biokerosene production via Fischer-Tropsch synthesis from lignocellulosic feedstock, and intensification of agricultural production. The use of carbon capture and storage (CCS) as well as netzero deforestation make significant contributions. We identify opportunities for Brazil, but synergies and trade-offs across sectors should be minded when designing climate policies. [ABSTRACT FROM AUTHOR]

Key message: The use of reduced planting spacings is an important strategy to increase the carbon storage in the above-belowground biomass and should be recommended for future exploitation of forest energy plantations when the purpose intended is the production of biomass for energy. Context: Recent concerns about global warming have resulted in more concerted studies on quantifying carbon storage in forest systems. Forest energy plantations play an essential role in the carbon storage. Aims: We proposed to evaluate the carbon storage and partitioning in short-rotation forest plantations and to characterize the elemental composition and energetic properties of the forest species Eucalyptus grandis W. Hill ex Maiden, Mimosa scabrella Benth, and Ateleia glazioviana Baill, grown under four planting spacings in Southern Brazil. Methods: A field study was conducted in order to evaluate forest carbon stock and wood composition using samples collected by direct method. The four spacings evaluated were 2.0 × 1.0, 2.0 × 1.5, 3.0 × 1.0, and 3.0 × 1.5 m. Results: The Eucalyptus grandis stored 327.1 Mg C ha−1 at 2.0 × 1.5-m spacing. When compared with the 3.0 × 1.5-m spacing, we observed a reduction of 29% in carbon stored. All forest species showed higher carbon storage in the following partitioning pattern: trunk>roots>branches>leaves>litter. Forest species energetic properties and elemental composition were not affected by planting spacing. On the other hand, variations according the tree portions were observed. For the carbon stocks in the soil, we observed an average accumulated carbon stock for the forest species studied of 77.4 Mg C ha−1 (0–40 cm). Conclusion: Forest managers can accelerate growth and increase the forest carbon storage and biomass yield by using reduced planting spacing that are smaller than the current pattern used by the majority of the forest producers, which is 3.0 × 1.5 m. For Eucalyptus grandis and Mimosa scabrella, the planting spacings recommended to produce biomass and improve carbon stocks were 2.0 × 1.5 and 2.0 × 1.0 m, respectively. [ABSTRACT FROM AUTHOR]

Coastal ecosystems are considered environments with great potential for carbon storage. Given the difficulties in quantifying biomass, allometric equations and remote sensing have become fundamental tools in the studies of quantification of vegetation biomass and carbon stocks. Thus, the objective of this study is to quantify and estimate the spatial distribution of vegetation biomass and to quantify the carbon stock of the Parnaíba River Delta vegetation. The study was carried out in part of the Parnaíba River Delta Environmental Protection Area and in the Parnaíba River Delta Marine Extractive Reserve, in NE Brazil, in five spots within distinct vegetation types: psammophile pioneer vegetation, dune subevergreen vegetation, mangrove evergreen vegetation, floodplain vegetation and vegetation associated with carnaubals. At 26 collection points, 10 × 20 m plots were marked, in which the diameter at breast height and height of all individuals were measured. The collected data were used in allometric equations for vegetation biomass estimates and these values were converted into carbon stocks. The spatial distribution of aboveground vegetation biomass (AGB) was also estimated by remote sensing, where we extracted and selected spectral variables obtained from Landsat-8 OLI sensor images, on three different dates. Prediction models were calculated by multiple linear regression analysis. It was observed that the mangrove evergreen vegetation obtained higher vegetation biomass and carbon stock than the others. The models obtained through remote sensing that provided the best estimates of AGB were those of November 12th, 2016 (EAM = 6.84; RMSE = 47.89 Mg ha−1; R2 = 0.72) and November 28th, 2016 (EAM = 9.63; RMSE = 34.67 Mg ha−1; R2 = 0.58). [ABSTRACT FROM AUTHOR]

This article describes a new concept to reduce carbon dioxide emissions of offshore oil production of high gas-to-oil ratio reservoirs and high content of CO2, denominated Offshore Salt Cavern Ultra-deep Water CCS (Carbon Capture and Storage) System. This hybrid system is intended for natural gas storage, the gravitational separation between CO 2 /CH 4 , and CO 2 confinement for final destination. This development emerged from a current demand of some Brazilian pre-salt reservoirs to destinate a gas stream with high CO 2 contamination, produced during the oil extraction. These reservoirs have a continuous salt rock layer of 2000 m as caprock making the construction possible of salt caverns by leaching using seawater. In the first stage of technology development, the system will only store a gas stream contaminated with a high concentration of CO 2. In the second stage of its development, it will allow not only the separation of natural gas from the CO 2 but also its storage and the monetization of CH 4. This paper presents the conceptual design of this technology, showing the steps from the parametric study to select the best relation between flowrate, leaching time, structural stability, and the volume of gas with the high content of CO 2 storage, up to the final geomechanical design using the set of parameters selected. [ABSTRACT FROM AUTHOR]

Energy-intensive industries have had to increase their production to meet global demands, consequently increasing their emissions of greenhouse gases (GHGs) such as CO2. Carbon dioxide is the raw material used in enhanced oil recovery (EOR) techniques, which have been gaining importance, taking into account the issues of global climate change and the potential to store CO2. The aim of this study was to develop a project analysis framework and assess the surface characteristics of candidate fields for CO2 injection projects located in the Recôncavo Basin, Bahia, Brazil, while also considering the present environmental restrictions. The methodology employed comprised a comprehensive review of the relevant literature and field visits to identify the important aspects for this preliminary assessment. Considering the present conditions of the surveyed fields and current environmental regulations, most of the analysed fields were verified to have a high potential for CO2 injection project implementation in Recôncavo Basin. [ABSTRACT FROM AUTHOR]

In recent years, nations, states and provinces have been proactively combating climate change, supported by the 21st Conference of the Parties of the United Nations Framework Convention on Climate Change (UNFCCC) outcomes. In the meantime, several studies have evaluated regional strategies for greenhouse gas (GHG) mitigation. Although these studies propose scenarios that meet the climate policy pledges, most of them are based on measures that have not been commercially demonstrated yet, such as carbon capture and storage (CCS). The aim of this work is to develop a low-carbon scenario for the energy sector in Sao Paulo, Brazil (whose emissions are significant at the regional and national level) until 2050 and to verify if a proven, technology-based approach meets the current policy goals. Although the analysis is based on a developing country, Sao Paulo state is the most developed region in Brazil. Consequently, the analysis presented in this work may be replicated in other regional settings, with distinct development stages, which demand increasing energy futures. In the business-as-usual (BAU) scenario, energy demand increases 2.6% per year until 2050, and emissions consequently increase 2.8% per year, reaching 235 million metric tons of carbon dioxide (tCO2). If four alternatives proposed in the low-carbon (LC) scenario were implemented, 28% of the BAU emissions would be avoided. However, even with this LC scenario, Sao Paulo would not meet the state pledge, remaining 44% above the policy emission cap. This result means that more audacious measures are needed to achieve an effective result. Such measures must push the current technical, scientific, and industrial knowledge and may require a biodiesel share over 20% in diesel blend, extensive increases in renewable energy supply, CCS, and bioenergy associated with CCS. Finally, we suggest some key points to apply this analysis in other regions, considering their own energy mix. [ABSTRACT FROM AUTHOR]

Biomass is responsible for 25% of the primary energy supply in Brazil. However, future biomass demand will be influenced by many factors. This study evaluates potential pathways for the utilization of biomass in Brazil until 2050, while considering novel biobased sectors (renewable jet fuel and biochemicals), resource competition, and greenhouse gas (GHG) emissions. Whereas other least‐cost optimization models assess biobased options to meet energy and chemicals demand in Brazil to a limited extent, this study provides a detailed breakdown of biomass feedstock, including an extensive portfolio of biomass conversion technologies. A least‐cost optimization model is used to assess the demand for energy and chemicals, and the competition between biomass and other climate‐mitigation measures such as renewable power generation technologies, carbon capture and storage (CCS), and energy efficiency. Varied over the three scenarios, 86–96% of the sustainable biomass supply potential is used. Under more stringent mitigation targets, novel biomass conversion technologies start to play an important role: Biobased electricity production with CCS, jet fuel production from lignocellulosic biomass, and chemicals are partly produced from ethanol and bio‐naphtha. The modeling framework provides a transparent view of which type of biomass can be used for which specific purpose. It is therefore an interesting tool for future research, for example to examine the dynamic interaction with demand for land. © 2019 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Successional agroforestry systems (SAFS) mimic the structure of natural forests while providing economical outputs. This study clarifies how carbon cycling and carbon sequestration change during successional development of SAFS. In Brazil, three successional stages of SAFS, 6, 12, and 34 years old, were compared in terms of carbon balance. Aboveground biomass, fruit harvest, litterfall, soil respiration, and soil organic carbon were measured for two years and analyzed. Carbon sequestration expressed by net primary productivity increased with age of SAFS from 9.8 Mg·ha-1·year-1 in 6-year-old system to 13.5 Mg·C·ha-1·year-1 in 34-year-old system. Accumulation of plant biomass and increased internal carbon cycling in SAFS led to an intensive sequestration of carbon. SAFS can be a sustainable way of agricultural production on vulnerable tropical soils. [ABSTRACT FROM AUTHOR]

Brazil faces an enormous challenge to implement its revised Forest Code. Despite big losses for the environment, the law introduces new mechanisms to facilitate compliance and foster payment for ecosystem services (PES). The most promising of these is a market for trading forest certificates (CRAs) that allows landowners to offset their restoration obligations by paying for maintaining native vegetation elsewhere. We analyzed the economic potential for the emerging CRA market in Brazil and its implications for PES programs. Results indicate a potential market for trading 4.2 Mha of CRAs with a gross value of US$ 9.2±2.4 billion, with main regional markets forming in the states of Mato Grosso and São Paulo. This would be the largest market for trading forests in the world. Overall, the potential supply of CRAs in Brazilian states exceeds demand, creating an opportunity for additional PES programs to use the CRA market. This expanded market could provide not only monetary incentives to conserve native vegetation, but also environmental co-benefits by fostering PES programs focused on biodiversity, water conservation, and climate regulation. Effective implementation of the Forest Code will be vital to the success of this market and this hurdle brings uncertainty into the market. Long-term commitment, both within Brazil and abroad, will be essential to overcome the many challenges ahead. [ABSTRACT FROM AUTHOR]

Although mangroves are recognized by high capacity of carbon storage and sequestration, few studies have been dedicated to determine the monetary value of this ecosystem service. Accordingly, the aim of this study is to assign monetary values to this service in a protected area (Southeastern Brazil). This economic valuation was performed considering preexisting estimates of carbon storage and sequestration in the aboveground biomass of these forests and average transaction values of carbon credits. The mean values of the service of carbon sequestration varied according to the physiographic type from 19.00 ± 10.00 US$ ha−1 yr−1(basin forests, high intertidal) to 82.28 ± 32.10 US$ ha−1 yr−1(fringe forests, low intertidal). Considering the area occupied by each physiographic type, the service of carbon sequestration may be worth up to 455,827 US$ yr−1. In regard to carbon storage, 3,477,041 US$ are stored in these forests, and values between 104,311 and 208,622 US$ ha−1 yr−1can be considered as the annual maintenance cost of this service. The income generated by future projects for the maintenance of carbon-related functions may represent a major advance for the conservation of this ecosystem. [ABSTRACT FROM PUBLISHER]

Organic residues management (ORM) alter plant traits and soil properties by changing nutrient and carbon cycling. It is unclear how ORM (mulching, compost, and their combination) applied for 18 months creates a mechanism to promote changes in a P. pyrifolia field. Our aim was to evaluate the influence of ORM on P. pyrifolia nutritional status, plant traits, yield, and carbon sequestration in a 16-year subtropical P. pyrifolia field. For this purpose, we performed an experiment in a randomized block design, using a factorial scheme 2 × 2, with the use of Compost and Mulching (e.g., presence and absence). The highest values of leaves N content, plant height, stem biomass, root biomass, total biomass, yield, and above- and belowground carbon (C) density were found on plots that received compost as the ORM. For soil organic C stock, the highest values were found on plots where mulching was applied. Finally, the highest values of total C density were found on plots that received the combination of Mulching and Compost. Our findings suggest that: (i) the use of Compost is the best alternative to promote leaves N content, plant height, stem dry biomass, root dry biomass, and total dry biomass, plant yield, and above- and belowground C density into a 16-year P. pyrifolia field into subtropical conditions; and (ii) the soil organic C stocks were improved using just the mulching treatment. The results highlight the importance of considering just one organic residue practice based on a sustainable way to improve both plant production and carbon sequestration, no differences were found between the use of compost and the combination of compost and mulching. [ABSTRACT FROM AUTHOR]

Planted forests include forests established through human planting or deliberate seeding. They are systems that offer us timber and non-timber forest products and ecosystem services, such as wildlife protection, carbon sequestration, soil, and watershed maintenance. Brazil has 7.6 million hectares of planted forests, with 72% of the total area occupied by Eucalyptus spp. A favorable climate and management and genetic improvement research are the main factors responsible for high productivity. In recent years, the expansion of planted areas has been accompanied by the commercial release of several pesticides, mainly herbicides. A recent change in the Brazilian legislation allows mixing phytosanitary products in a spray tank, having a new approach to managing pests, diseases, and weeds. Antagonism is the main risk of tank mixes, and to reduce the dangers associated with this practice, we review all products registered for growing Eucalyptus. This literature review aims to identify the effects of product mixtures registered for Eucalyptus reported for other crops. In addition, environmental and social risk assessment has been widely adopted to export wood and cellulose, making the results of this review an indispensable tool in identifying the nature and degree of risks associated with pesticides. The results classify the effects of the mixtures as an additive, antagonistic or synergistic. The use of pesticide tank mixtures has the potential for expansion. However, there are still challenges regarding variations in the effects and applications in different climatic conditions. Therefore, studies that prove efficient mixtures for the forest sector are essential and the training of human resources. [ABSTRACT FROM AUTHOR]

groforestry systems can play a major role in the sequestration of carbon (C) because of their higher input of organic material to the soil. The importance of organic carbon to the physical, chemical, and biological aspects of soil quality is well recognized. However, total organic carbon measurements might not be sensitive indicators of changes in soil quality. Adoption of procedures that can extract the more labile fraction preferentially might be a more useful approach for the characterization of soil organic carbon resulting from different soils. This study aimed to evaluate organic carbon (C) fractions distribution in different soil layers up to 50 cm depth in two soil orders under cacao ( Theobroma cacao) agroforestry systems (AFS) in Bahia, Brazil. Soil samples were collected from four depth classes (0-5, 5-10, 10-30 and 30-50 cm) under two cacao agroforestry systems (30-year-old stands of cacao with Erythrina glauca, as shade trees) in Latosol and Cambisol, in Bahia, Brazil. The determination of oxidizable carbon by a modified Walkley-Black method was done to obtain four C fractions with different labile forms of C (fraction 1: labile fraction; fraction 2: moderate labile fraction; fraction 3: low labile fraction and fraction 4: recalcitrant fraction). Overall, at two cacao AFS, the C fractions generally declined with increase in soil depth. The C fractions 1 and 2 were 50% higher on upper layers (0-5 and 5-10 cm). More than 50% of organic C was found in more labile fraction (fraction 1) in all depths for both soils. High value of C fraction 1 (more labile C)-to-total organic C ratio was obtained (around 54-59%, on Latosol and Cambisol, respectively), indicating large input of organic matter in these soils. [ABSTRACT FROM AUTHOR]

The article discusses research on the conversion of Brazilian Atlantic Forest and provision of ecosystem services in the area. The study by E. H. Ditt el al evaluated the benefits and costs of land use patterns and quantified ecosystem services from different land use in the Atibainha Reservoir to determine the impact of land use changes considering four ecosystem services including carbon sequestration and purification of water. Findings indicated that the most important services that native forest can provide include carbon sequestration.

Conservation agriculture can provide a low-cost competitive option to mitigate global warming with reduction or elimination of soil tillage and increase soil organic carbon (SOC). Most studies have evaluated the impact of zero till (ZT) only on surface soil layers (down to 30 cm), and few studies have been performed on the potential for C accumulation in deeper layers (0–100 cm) of tropical and subtropical soils. In order to determine whether the change from conventional tillage (CT) to ZT has induced a net gain in SOC, three long-term experiments (15–26 years) on free-draining Ferralsols in the subtropical region of South Brazil were sampled and the SOC stocks to 30 and 100 cm calculated on an equivalent soil mass basis. In rotations containing intercropped or cover-crop legumes, there were significant accumulations of SOC in ZT soils varying from 5 to 8 Mg ha−1 in comparison with CT management, equivalent to annual soil C accumulation rates of between 0.04 and 0.88 Mg ha−1. However, the potential for soil C accumulation was considerably increased (varying from 0.48 to 1.53 Mg ha−1 yr−1) when considering the soil profile down to 100 cm depth. On average the estimate of soil C accumulation to 100 cm depth was 59% greater than that for soil C accumulated to 30 cm. These findings suggest that increasing sampling depth from 30 cm (as presently recommended by the IPCC) to 100 cm, may increase substantially the estimates of potential CO2 mitigation induced by the change from CT to ZT on the free-draining Ferralsols of the tropics and subtropics. It was evident that that legumes which contributed a net input of biologically fixed N played an important role in promoting soil C accumulation in these soils under ZT, perhaps due to a slow-release of N from decaying surface residues/roots which favored maize root growth. [ABSTRACT FROM AUTHOR]

Sugarcane (Saccharum officinarum L.) cultivation leaves behind around 20 t ha−1 of biomass residue after harvest and processing. We investigated the potential for sequestering carbon (C) in soil with these residues by partially converting them into biochar (recalcitrant carbon-rich material). First, we modified the RothC model to allow changes in soil C arising from additions of sugarcane-derived biochar. Second, we evaluated the modified model against published field data, and found satisfactory agreement between observed and predicted soil C accumulation. Third, we used the model to explore the potential for soil C sequestration with sugarcane biochar in São Paulo State, Brazil. The results show a potential increase in soil C stocks by 2.35 ± 0.4 t C ha−1 year−1 in sugarcane fields across the State at application rates of 4.2 t biochar ha−1 year−1. Scaling to the total sugarcane area of the State, this would be 50 Mt of CO2 equivalent year−1, which is 31% of the CO2 equivalent emissions attributed to the State in 2016. Future research should (a) further validate the model with field experiments; (b) make a full life cycle assessment of the potential for greenhouse gas mitigation, including additional effects of biochar applications on greenhouse gas balances. [ABSTRACT FROM AUTHOR]

Forests in the southwestern Amazon are rich, diverse, and dense. The region is of high ecological importance, is crucial for conservation and management of natural resources, and contains substantial carbon and biodiversity stocks. Nevertheless, few studies have developed allometric equations for this part of the Amazon, which differs ecologically from the parts of Amazonia where most allometric studies have been done. To fill this gap, we developed allometric equations to estimate the volume, biomass, and carbon in commercial trees with diameter at breast height (DBH) ≥ 50 cm in an area under forest management in the southeastern portion of Brazil's state of Acre. We applied the Smalian formula to data collected from 223 felled trees in 20 species, and compared multiple linear and nonlinear models. The models used diameter (DBH) measured at 1.30 m height (d), length of the commercial stem (l), basic wood density (p), and carbon content (t), as independent variables. For each dependent variable (volume, biomass, or carbon) we compared models using multiple measures of goodness-of-fit, as well as graphically analyzing residuals. The best fit for estimating aboveground volume of individual stems using diameter (d) and length (l) as variables was obtained with the Spurr model (1952; logarithmic) (root mean square error (RMSE) = 1.637, R² = 0.833, mean absolute deviation (MAD) = 1.059). The best-fit equation for biomass, considering d, l, and p as the explanatory variables, was the Loetsch et al. (1973; logarithmic) model (RMSE = 1.047, R² = 0.855, MAD = 0.609). The best fit equation for carbon was the Loetsch et al. (1973; modified) model, using the explanatory variables d, l, p, and t (RMSE = 0.530, R² = 0.85, MAD = 0.304). Existing allometric equations applied to our study trees performed poorly. We showed that the use of linear and nonlinear allometric equations for volume, biomass, and carbon can reduce the errors and improve the estimation of these metrics for the harvested stems of commercial species in the southwestern Amazon. [ABSTRACT FROM AUTHOR]

Hybrid eucalypt clones are grown for fiber production worldwide and to provide an ecosystem service that can store atmospheric carbon at a very fast rate. This study assessed the carbon stocks in the soil and various tree fractions in a 10-year-old plantation of Eucalyptus urophylla S.T. Blake × Eucalyptus globulus Labill. in Southern Brazil. Four experimental plots were established, and an inventory of Eucalyptus trees was conducted by considering five diametric classes. Three trees in each diametric class were harvested for biomass and carbon quantification. The understory biomass of native trees was quantified in five subplots and the litter was quantified in 16 subplots. Organic C was quantified in the soil (SOC) and roots (diameter ≤ 0.5 cm) to a depth of 100 cm. The C concentration in the different biomass fractions of the eucalyptus trees were 55.7% (±0.6), 50.4% (±0.4), 49.5% (±0.6) and 45.4 % (±0.9) for leaves, branches, wood and bark, respectively. The C concentrations in the understory fractions were 51.4% (±1.0) for the canopy and 50.0% (±0.9) for the stem. The carbon concentration in the fine root biomass was 45.7% (±1.4). Soil C concentrations were 1.23% (±0.32), 0.97% (±0.10), 0.45% (±0.14), and 0.24% (±0.10) for depths of 0–25, 25–50, 50–75, and 75–100 cm. C was allocated in: (a) the trees (aboveground fraction = 118.45 Mg ha−1 and belowground fraction = 30.06 Mg ha−1), (b) the understory = 1.44 Mg ha−1, (c) the litter = 8.34 Mg ha−1, and (d) the soil (without roots) = 99.7 Mg ha−1. The share of total C stock (a + b + c + d = 258.0 Mg ha−1) was similar in the aboveground (49.7%) and belowground (50.3%) fractions, thus indicating a very high rate of C sequestration in the biomass. Eucalyptus plantations in Brazil are fast growing (for this study = 36.7 m³ ha−1 year−1) and contribute to intense carbon sequestration in above and belowground biomass (14.8 Mg ha−1 year−1). [ABSTRACT FROM AUTHOR]