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Estimating fire emissions in the Brazilian Cerrado requires a comprehensive approach, combining data, fire and vegetation modelling techniques, and policy. Although high quantities of global fire emissions come from the Cerrado, research in this area is still overlooked when compared to other savanna countries. This study systematically reviewed 69 papers on fire emissions from the Cerrado. The aim was to provide insights into the placement of the Cerrado in the atmospheric carbon budget and support improved estimation of the Biome’s carbon balance. Our review finds that, in the Cerrado, studies often focus on quantifying fire dynamics parameters and emissions, and that a holistic approach is required to estimate fire emissions, which is hindered due to the difficulty in valuing the qualitative aspects of fire. Evidence suggests a rise in interest in understanding fire emissions in the Cerrado, reflected in the increased number of studies throughout the years. More research is required to understand the aspects of fire dynamics in the Cerrado, how these reflect fire emissions locally and globally and potential mitigation activities. This could be achieved by including fire management representation in land surface models and using observational data to constrain and assess their utility.

Tropical deforestation impacts the climate through complex land-atmosphere interactions causing local and regional warming. However, whilst the impacts of deforestation on local temperature are well understood, the regional (nonlocal) response is poorly quantified. Here, we used remote-sensed observations of forest loss and dry season land-surface temperature during the period 2001 to 2020 to demonstrate that deforestation of the Amazon caused strong warming at distances up to 100 km away from the forest loss. We apply a machine learning approach to show nonlocal warming due to forest loss at 2-100 km length scales increases the warming due to deforestation by more than a factor 4, from 0.16 K to 0.71 K for each 10-percentage points of forest loss. We estimate that rapid future deforestation under a strong inequality scenario could cause dry season warming of 0.96 K across Mato Grosso state in southern Brazil over the period 2020 to 2050. Reducing deforestation could reduce future warming caused by forest loss to 0.4 K. Our results demonstrate the contribution of tropical deforestation to regional climate warming and the potential for reduced deforestation to deliver regional climate adaptation and resilience with important implications for sustainable management of the Amazon.

Approximately 2.5 × 10 6 square kilometers of the Amazon forest are currently degraded by fire, edge effects, timber extraction, and/or extreme drought, representing 38% of all remaining forests in the region. Carbon emissions from this degradation total up to 0.2 petagrams of carbon per year (Pg C year −1 ), which is equivalent to, if not greater than, the emissions from Amazon deforestation (0.06 to 0.21 Pg C year −1 ). Amazon forest degradation can reduce dry-season evapotranspiration by up to 34% and cause as much biodiversity loss as deforestation in human-modified landscapes, generating uneven socioeconomic burdens, mainly to forest dwellers. Projections indicate that degradation will remain a dominant source of carbon emissions independent of deforestation rates. Policies to tackle degradation should be integrated with efforts to curb deforestation and complemented with innovative measures addressing the disturbances that degrade the Amazon forest.

Projections of future carbon sinks and stocks are important because they show how the world's ecosystems will respond to elevated CO2 and changes in climate. Moreover, they are crucial to inform policy decisions around emissions reductions to stay within the global warming levels identified by the Paris Agreement. However, Earth System Models from the 6th Coupled Model Intercomparison Project (CMIP6) show substantial spread in future projections—especially of the terrestrial carbon cycle, leading to a large uncertainty in our knowledge of any remaining carbon budget (RCB). Here we evaluate the global terrestrial carbon cycle projections on a region-by-region basis and compare the global models with regional assessments made by the REgional Carbon Cycle Assessment and Processes, Phase 2 activity. Results show that for each region, the CMIP6 multi-model mean is generally consistent with the regional assessment, but substantial cross-model spread exists. Nonetheless, all models perform well in some regions and no region is without some well performing models. This gives confidence that the CMIP6 models can be used to look at future changes in carbon stocks on a regional basis with appropriate model assessment and benchmarking. We find that most regions of the world remain cumulative net sources of CO2 between now and 2100 when considering the balance of fossil-fuels and natural sinks, even under aggressive mitigation scenarios. This paper identifies strengths and weaknesses for each model in terms of its performance over a particular region including how process representation might impact those results and sets the agenda for applying stricter constraints at regional scales to reduce the uncertainty in global projections.

In this chapter, we examine the main components of greenhouse gas budgets from tropical terrestrial and aquatic environments, including how these components are measured and modeled at scales ranging from field plots to regions. We discuss uncertainties associated with measurements and models, review the most current knowledge, and present efforts underway to further advance our knowledge of the tropic greenhouse gas budget., isbn: 9780128149522, Volume: 1, Pages: 271-309

The future of land use and cover change in Brazil, particularly due to deforestation and forest restoration processes, is critical for the future of global climate and biodiversity, given the richness of its five biomes. These changes in Brazil depend on the interlink between global factors due to its role as one of the main exporters of commodities globally and the national to local institutional, socioeconomic, and biophysical contexts. Aiming to develop scenarios that consider the balance between global (e.g., GDP growth, population growth, per capita consumption of agricultural products, international trade policies, and climatic conditions) and local factors (e.g., land use, agrarian structure, agricultural suitability, protected areas, distance to roads, and other infrastructure projects), a new set of land-use change scenarios for Brazil were developed that aligned with the global structure Shared Socioeconomic Pathways (SSPs) and Representative Concentration Pathway (RCPs) developed by the global change research community. The narratives of the new scenarios align with SSP1/RCP 1.9 (Sustainable development scenario), SSP2/RCP 4.5 (Middle of the road scenario), and SSP3/RCP 7.0 (Strong inequality scenario). The scenarios were developed by combining the LuccME spatially explicit land change allocation modeling framework and the INLAND surface model to incorporate the climatic variables in water deficit. Based on detailed biophysical, socioeconomic, and institutional factors for each biome in Brazil, we have created spatially explicit scenarios until 2050, considering the following classes: forest vegetation, grassland vegetation, planted pasture, agriculture, a mosaic of small land uses, and forestry. The results aim to detail global models regionally. They could be used regionally to support decision-making and enrich the global analysis.

This review presents how the boreal and the tropical forests affect the atmosphere, its chemical composition, its function, and further how that affects the climate and, in return, the ecosystems through feedback processes. Observations from key tower sites standing out due to their long-term comprehensive observations: The Amazon Tall Tower Observatory in Central Amazonia, the Zotino Tall Tower Observatory in Siberia, and the Station to Measure Ecosystem-Atmosphere Relations at Hyytiäla in Finland. The review is complemented by short-term observations from networks and large experiments. The review discusses atmospheric chemistry observations, aerosol formation and processing, physiochemical aerosol, and cloud condensation nuclei properties and finds surprising similarities and important differences in the two ecosystems. The aerosol concentrations and chemistry are similar, particularly concerning the main chemical components, both dominated by an organic fraction, while the boreal ecosystem has generally higher concentrations of inorganics, due to higher influence of long-range transported air pollution. The emissions of biogenic volatile organic compounds are dominated by isoprene and monoterpene in the tropical and boreal regions, respectively, being the main precursors of the organic aerosol fraction. Observations and modeling studies show that climate change and deforestation affect the ecosystems such that the carbon and hydrological cycles in Amazonia are changing to carbon neutrality and affect precipitation downwind. In Africa, the tropical forests are so far maintaining their carbon sink. It is urgent to better understand the interaction between these major ecosystems, the atmosphere, and climate, which calls for more observation sites, providing long-term data on water, carbon, and other biogeochemical cycles. This is essential in finding a sustainable balance between forest preservation and reforestation versus a potential increase in food production a

Anthropogenic transformations, which have become intensified by land use and land cover changes and industrialization, have contributed to increased anthropogenic pressure on biodiversity. These disturbances contribute toward fragmentating habitats at different scales and putting species at risk, in addition to compromising the main biogeochemical cycles. To better understand the spatiotemporal dynamics of anthropogenic pressure on Brazilian biomes, this study sought to develop a composite index to identify and analyze the degree and distribution of anthropogenic-based pressure on biodiversity, and identify internally homogeneous and heterogeneous regions regarding the dynamics of this pressure in different scenarios. To that end, we carried out an analysis of the impact of select anthropogenic factors. Specifically, we analyzed future scenarios involving land use and land cover changes in line with the global structure Shared Socio-Economic Pathways (SSPs) and Representative Concentration Pathways (RCPs), according to the narratives SSP1/RCP 1.9, SSP2/ RCP 4.5 and SSP3/RCP 7.0. We used cluster and spatial analyses to determine the spatial dynamics of the index and, consequently, the regions most susceptible to anthropogenic pressure. The results demonstrate intensified pressure on biodiversity in areas that have already been subject to a considerable degree of disturbances, especially the Cerrado, Caatinga, and Atlantic Forest biomes. In all scenarios, the region with the highest average pressure index, i.e., Region 4, which has an average pressure index of 0.57, corresponds to 30% of Brazilian territory. This method made it possible to determine the level of pressure in each region and, subsequently, identify the regions that have been most affected by human actions in an effort to guide priority actions and local policies. However, it should be noted that this approach should be complemented with additional information, such as soil erosion, field recognition, an

Regional land carbon budgets provide insights into the spatial distribution of the land uptake of atmospheric carbon dioxide and can be used to evaluate carbon cycle models and to define baselines for land-based additional mitigation efforts. The scientific community has been involved in providing observation-based estimates of regional carbon budgets either by downscaling atmospheric CO2 observations into surface fluxes with atmospheric inversions, by using inventories of carbon stock changes in terrestrial ecosystems, by upscaling local field observations such as flux towers with gridded climate and remote sensing fields, or by integrating data-driven or process-oriented terrestrial carbon cycle models. The first coordinated attempt to collect regional carbon budgets for nine regions covering the entire globe in the RECCAP-1 project has delivered estimates for the decade 2000–2009, but these budgets were not comparable between regions due to different definitions and component fluxes being reported or omitted. The recent recognition of lateral fluxes of carbon by human activities and rivers that connect CO2 uptake in one area with its release in another also requires better definitions and protocols to reach harmonized regional budgets that can be summed up to a globe scale and compared with the atmospheric CO2 growth rate and inversion results. In this study, using the international initiative RECCAP-2 coordinated by the Global Carbon Project, which aims to be an update to regional carbon budgets over the last 2 decades based on observations for 10 regions covering the globe with a better harmonization than the precursor project, we provide recommendations for using atmospheric inversion results to match bottom-up carbon accounting and models, and we define the different component fluxes of the net land atmosphere carbon exchange that should be reported by each research group in charge of each region. Special attention is given to lateral fluxes, inland water flu

An improved version of the Integrated Land Surface Model (INLAND), incorporating the physical, ecological and hydrological parameters and processes pertaining to two subclasses of tropical forest in the central Amazon basin, a poorly drained flat plateau and a well-drained adjacent broad valley, is used to simulate the hydrological, energy and CO2 fluxes. The model is forced with observed meteorological data. The experimental output data from the model runs are compared with observational data at the two locations. The seasonal variabilities of water table depth at the valley site and the soil moisture at the plateau site are satisfactorily simulated. The two locations exhibit large differences in energy, carbon and water fluxes, both in the simulations and in the observations. Results validate the INLAND model and indicate the need for incorporating sub-grid scale variability in the relief, soil type and vegetation type attributes to improve the representation of the Amazonian ecosystems in land-surface models., This work was supported by the São Paulo Research Foundation (FAPESP) Grant Number 2017/22269-2. The first author was funded by The National Council of Scientific and Technological Development (CNPq) and National Coordination for High Level Education and Training (CAPES). The second author was supported by CNPq Grant Number 314780/2020-3. The fourth author was supported by Grant Number 2308.019802/2018-7, PVNS (National Senior Visiting Professor) program by CAPES in Brazil and CNPq in Brazil for research Grant number PQ 306595/2013-3., Peer Reviewed, Postprint (published version)