Search

The article examines to what extent the adverse effects of climate change can be considered triggering factors of public insecurity. Against this background, it explores the growing environmental conflicts involving water resources in Brazil, including the Amazon region. In addition to the introduction and conclusion, the paper is structured around three topics. The first one outlines how the concept of public security has evolved to the present state, in which climate change is taken into account. Next, climate change is discussed as a factor that magnifies vulnerabilities, an argument supported by a discussion of historical events. The third topic highlights the main threats, vulnerabilities and conflicts involving water resources in Brazil, taking a scientific view of systemic risks and precaution. Finally, we propose rethinking the concept of public security in Brazil from a perspective of parameters involving regulations, principles and state initiative. The article suggests that the immediate and future effects of climate change do have a profound impact on social systems and on the environment, and may be a triggering factor of public insecurity. If institutions and governments do not address existing effects, and invest in adaptations to meet future scientific forecasts on climate change, social stability and the development of a culture of peace will be less likely in Brazil. A fundamental step in this process is the reformulation of the conventional concept of public security in the Brazilian legislation, in order to expressly incorporate the variable of climate security among its stated objectives. In addition, we point out a set of actions and principles with the potentital to promote not only adaptation and resilience, but also contribute to building peace. In terms of methodology, the study is descriptive, exploratory, legislative, bibliographical and documentary. [ABSTRACT FROM AUTHOR]

Semi-arid regions are known for erratic precipitation patterns with significant effects on the hydrological cycle and water resources availability. High temporal and spatial variation in precipitation causes large variability in runoff over short durations. Due to low soil water storage capacity, base flow is often missing and rivers fall dry for long periods. Because of its climatic characteristics, the semi-arid north-eastern region of Brazil is prone to droughts. To counter these, reservoirs were built to ensure water supply during dry months. This paper describes problems and solutions when calibrating and validating the eco-hydrological model SWIM for semi-arid regions on the example of the Pajeú watershed in north-eastern Brazil. The model was calibrated to river discharge data before the year 1983, with no or little effects of water management, applying a simple and an enhanced approach. Uncertainties result mainly from the meteorological data and observed river discharges. After model calibration water management was included in the simulations. Observed and simulated reservoir volumes and river discharges are compared. The calibrated and validated models were used to simulate the impacts of climate change on hydrological processes and water resources management using data of two representative concentration pathways (RCP) and five earth system models (ESM). The differences in changes in natural and managed mean discharges are negligible (< 5%) under RCP8.5 but notable (> 5%) under RCP2.6 for the ESM ensemble mean. In semi-arid catchments, the enhanced approach should be preferred, because in addition to discharge, a second variable, here evapotranspiration, is considered for model validation. [ABSTRACT FROM AUTHOR]

Purpose: This paper presents the regionalized water scarcity characterization factors (CFs) of the available water remaining (AWARE) model, which was found by a previous study, on the water scarcity in Brazil, to be the most indicative characterization model for the water-scarce regions in Brazil. We used the national database and hydrographic delimitations defined by the National Water Agency (Agência Nacional de Águas — ANA) to generate the regionalized AWARE BR CFs. Methods: The CFs were regionalized by hydrographic delimitations used by ANA: (i) State Hydrographic Units (SHU) and (ii) Hydrographic Regions (HR). These AWARE BR CFs were compared with the factors originally proposed by WULCA (2018) and with the Scarcity Index used by ANA to identify the scarcest regions in the country. Finally, the AWARE and AWARE BR factors were applied to a case study of Brazilian melons, evaluating the regionalization effects on the results of water scarcity analysis. Results and discussion: The AWARE BR CFs demonstrate most consistency with the regions recognized by ANA to have water scarcity problems, such as the semiarid region. Approximately 12% of the SHUs exhibited maximum water scarcity (CF = 100) during the entire year, while 11% presented minimum scarcity factors (CF = 0.1). The comparison of hydrologic data from ANA with those from WaterGAP indicated that water availability was overestimated in WaterGAP, while demand was underestimated in different basins. The comparison of AWARE BR CFs with ANA Scarcity Index values indicated more similarity (smaller residual error) than the comparison of AWARE BR CFs with AWARE. The case study regarding the impact of water scarcity on melons showed a significant difference between characterization factors and, consequently, in the values of impact. Conclusions: AWARE BR factors generated with national characterization data are adapted to the different regions of Brazil, exhibiting higher sensitivity to the semiarid region. This regionalization provided a more accurate representation of the scarcity in smaller basins located in larger basins, characterized by large climate variation. [ABSTRACT FROM AUTHOR]

The vulnerability of electric potential generation from water resources has been evidenced due to uncertainties of climatic origin and energy planning. Changes in rainfall regimes are multifactorial phenomena difficult to model. Rainfall is the main natural way of restoring the reservoir levels of hydroelectric power plants. The reduction in rainfall levels may increase in the coming years, resulting in a probable change of the energy matrix configuration of the state of Minas Gerais (MG). This could reduce the share of renewable sources increasing dependence on the importance of energy from fossil fuels, which are the immediate primary sources of energy available. Prior examinations have portrayed the depletion of hydroelectricity in Brazil, or its macro-regions, however this work tries to supply a more focused look at the effects on the electricity and social sectors of the state of Minas Gerais. The study developed in this paper aims to investigate the hydrological potential alteration impacts and consequences on the energy matrix of the state, the greenhouse gas emissions and the social reflexes of these changes due to scenarios motivated by climate change. The investigation intends to show the importance of the water-energy-emissions nexus for energy planning and decision-making, in order to evaluate the best options for dealing with adverse and potentially destabilizing conditions. The results of the analyses show that while hydropower demand was 5.24 Mtoe in 2015, in 2030 the supply of hydropower will be 5.81 Mtoe and 4.72 Mtoe, for the conservative and severe scenarios, respectively. In addition, the effect of climate change may require an increase in the share of non-renewable sources in the energy matrix, which could increase CO 2 e emissions from 4.2% to 7.4% by 2030, compared to the levels in 2016. • Reduction in rainfall levels will change the energy matrix configuration of MG state. • Population growth will boost demand for energy. • It is shown the importance of the water-energy-emissions nexus for energy planning and decision-making. • The energy matrix may considerably increase the CO 2 e emissions by 2030, compared with 2016 levels in the MG state. [ABSTRACT FROM AUTHOR]

Understanding how climate affects tree growth is crucial for assessing climate change impacts on forests. Furthermore, trees in more competitive environments appear to respond to climate differently than trees in less competitive environments. An important tool for investigating the growth-environment relationships is tree ring dating. This study aimed to characterize the climatic factors that affect Pinus taeda growth in southern Brazil in two distinct stand types: open growth trees and competing trees. We hypothesized that competing trees present more vulnerable responses to climate variability than open growth trees. Thus, we used increment borers to access long-term growth through tree rings. Pearson’s correlation was applied to compare radial growth with monthly and annual climatic data. The chronologies generated for the two environments present similar year-to-year growth patterns. However, competing trees are more sensitive under limiting climate conditions than open growth trees. Water availability during the current spring/summer was the primary climate constraint for P. taeda growth in the region, followed by high temperatures during the summer, probably due to photosynthetic restrictions. The paper provides additional information on climatic factors that contribute to growth models and reports an important research field, considering planning forest management in the future. [ABSTRACT FROM AUTHOR]

Changes in Brazil's climate have aggravated drought conditions, yet the government continues to favor populist policies over ensuring sustainable energy and water resources. This paper analyses the underlying environmental and policy conditions that have led to Brazil's current power and water crisis and argues in favor of an overhaul of the federal energy infrastructure to reduce political influence in a regulated market and to improve initiatives of reforestation to mitigate the effects of climate change. The effects of poor climate and energy policies so clearly manifested in the Brazilian crisis should serve as a warning to other countries that sustainability is a choice, not a causal eventuality. [ABSTRACT FROM AUTHOR]