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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]

• 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]

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]

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]

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]