Catástrofe, crise, desaparecimento, extinção, ameaça, medos, riscos, descrença, colapso, desastres. Com a intensificação da ocorrência de eventos extremos e alterações climáticas, vivemos a disseminação de enunciados niilistas marcados pelo fim e pela vontade de nada, trazendo novo fôlego para o velho catastrofismo. Proliferam distopias em torno de uma ausência de futuro à qual estaríamos condenados. A sensação de que “não há saída”, por vezes, coloca-nos diante da impotência do pensamento para avaliar situações que se tornaram impensáveis em relação ao modo com o qual estamos habituados a lidar com o tempo, o humano, a natureza, o corpo, o espaço, a cultura, a tecnologia, a política… A contemporaneidade lança-nos o desafio do enfrentamento da extinção de espécies animais e vegetais, da erosão do solo, da elevação do nível da água, das modificações extremas de ambientes e paisagens, do colapso dos recursos hídricos, mas também e, conjuntamente, do desaparecimento, erosão e colapso das existências singulares, humanas e não humanas, aí implicadas, problematizando os modos de pensar a preservação e a conservação, a gestão pública, e as reinvindicações por visibilidade e justiça que nos chegam de todas as partes. Diante de tantos desaparecimentos afirma-se a urgência ética, estética e política da criação de outros pensamentos, narrativas, conceitos, imagens, práticas, ações, fabulações, ficções-científicas, especulações… Como podemos fazer aparecer outros modos de existência nas situações
de contingência? A partir de quais lógicas de funcionamento a comunicação, as ciências, as tecnologias, a filosofia e as artes têm feito aparecer os desaparecimentos em seus bancos de dados, coleções, museus,
patrimônios, catálogos, acervos, inventários, pesquisas e escritas? Diante da obsessão contemporânea com a criação de arquivos e seus movimentos de coleta, identificação, codificação e documentação, como fazer durar o acontecimento? Como tornar possível a extração de forças de vida dos arquivos? Para dar corpo e consistência a outros modos de dizer, escrever, ver e escutar o “Desaparecimento”, tema desta terceira edição da revista ClimaCom Cultura Científica – Pesquisa, Jornalismo e Arte, apresentamos duas entrevistas, com a filósofa belga Isabelle Stengers e o filósofo e sociólogo francês Bruno Latour, e uma série instigante de produções artísticas e de artigos de pesquisadores brasileiros e também da Austrália, Catalunha e Colômbia que põem em jogo as multidimensões do desaparecimento implicadas nas mudanças climáticas. Não se trata apenas do que desaparece nesse complexo e mutante cenário, mas de como o pensamento e a sensibilidade tomam para si o desaparecimento para fazer dele a ocasião de incontáveis e surpreendentes aparições.

This study aims to calculate indicators and indexes to subsidize the analysis of vulnerability and adaptation of the renewable energy sector to climate change in Brazil, focusing on biofuels and solar energy. For biofuels, in general, the Brazilian coast will be a propitious area for agricultural productivity during the XXI century, but these are areas historically intended for occupation and development of the urbanization process, that is, with limited land availability and supply for primary production. In some parts of the Northeast, Midwest and South of the country, offer for the cultivation land will be reduced. For the solar energy is observed that Brazil has area and highly expressive power for the use of this power, both today and in the coming decades, especially in the North, Northeast and Midwest. In statistical terms, the Mann-Kendal test and Sen’s Bend point to a very weak tendency to useful radiation indicator in all regions of Brazil by 2100. In addition, it is projected a significant increase in mean air temperature by the end of XXI century across the country that can mean a reduction in power conversion capability, which is sensitive to ambient temperature variations, especially in the Midwest and North of the country.

This study aimed to quantify nitrous oxide (N₂O) and methane (CH₄) emission/sink response from sugar cane soil treated with fertilizer nitrogen (N) and vinasse applied separately or in sequence, the latter being investigated with regard to the time interval between applications for a possible effect on emissions. The study was carried out in a traditional area of unburned sugar cane in São Paulo state, Brazil. Two levels of N fertilization (0 and 100 kg N ha^–1) with no added vinasse and combined with vinasse additions at different times (100 m^–3 ha^–1 at 3 and 15 days after N fertilization) were evaluated. Methane and N₂O fluxes were monitored for 211 days. On average, the soil was a sink for CH₄, which was not affected by the treatments. Emissions of N₂O were induced by N fertilizer and vinasse applications. For ammonium sulfate, 0.6% of the added N was emitted as N₂O, while for vinasse, this ranged from 1.0 to 2.2%. Changes in N₂O fluxes were detected the day after application of vinasse on the N fertilized areas, but although the emission factor (EF) was 34% greater, the EF was not significantly different from fertilizer N alone. Nevertheless, we recommend to not apply vinasse after N fertilization to avoid boosting N₂O emissions.

This study evaluates the chemical processes responsible for the nitrous oxide (N₂O) and methane (CH₄) fluxes in the managed pasture (PM) and unmanaged pasture (PNM). In addition, the impact of nitrogen fertilization on the N₂O and CH₄ fluxes was assessed. The experiments were conducted on three farms in Alta Floresta city in the state of Mato Grosso. Both regular and intensive samples were collected from PM, PNM, and forest areas for each of the properties. The gases were sampled using static chambers in the morning. Higher N₂O fluxes were recorded in the PMs, whereas the CH₄ fluxes showed no influence of nitrogen fertilization in both regular and intensive samples. Low fertilizer levels resulted in low N₂O emissions.

Soil amendment with biochar has been claimed as an option for carbon (C) sequestration in agricultural soils. Most studies on biochar/soil organic carbon (SOC) interactions were executed under laboratory conditions. Here we tested the stability of biochar produced in a traditional kiln and its effects on the stocks of native SOC under field conditions. The biochar was characterized using pyrolysis–gas chromatography–mass spectrometry, and then added to an Oxisol under savannah climate. This soil was amended with 0, 5, 10, 20 and 40 Mg ha−1 of biochar in a randomized complete block design with four replications and cultivated with soybean over four cropping seasons (CSs; 120 days each). Soil samples from the 0–10 cm top layer were collected at the end of the first and fourth CSs and analyzed for CO2 emissions, isotopic C abundance (13C/12C ratio) and enzymatic activity (fluorescein diacetate and dehydrogenase). The biochar showed a low degree of thermal modification. Its relative decomposition rate was higher (k = 0.32–1.00 year−1) than generally claimed (k = 0.005–0.0005 year−1), and higher than the decomposition of native SOC (k = 0.22 year−1). Addition of biochar didnot affect the stocks of native SOC. Our findings highlight the need for critically reviewing the potential of locally produced biochar to sequester C.

This paper proposes an indirect method to elicit experts’ opinions. The approach is an attempt to balance accuracy and time consumption (efficiency) in elicitation exercises. Each step of the proposed method involves two types of questions: first, the expert is asked about which of two subintervals most likely holds the unknown of interest (a procedure similar to the binary search algorithm); then, the expert assigns a credibility level on which he bases his decision. A set of Bayesian intervals of the unknown is thereby obtained, and the probability distribution underlying expert’s beliefs is approached. The usefulness of the method is analysed by means of: 1) a comparison with established methods from the literature (e.g., the direct and bisection methods); 2) its application to a real world case within the context of probabilistic risk analysis.

This study investigates long-term climate trends in Pernambuco, Northeast Brazil (Nordeste), and in the Tropical Atlantic islands of Fernando de Noronha and Cape Verde. The study is based on meteorological station time series and model simulations of present and future climates. Past trends are compared with numerical simulations of present and future climate scenarios for the periods of 1960-2000 and 2010-2050. Both the station data analyses and numerical simulations revealed trends of increasing temperature maxima and diminishing precipitation. While station data analyses showed modest warming in Fernando de Noronha they revealed strong warming and drying trends in Cape Verde similar to the trends detected over the semiarid Nordeste. The water-balance calculations for the study sites showed reduced soil moisture availability and total rainfall in all areas. The observed temperature and precipitation trends are indicative that aridification processes are underway in Pernambuco and Cape Verde. The atmospheric model simulations were consistent with the station data regarding the present warming; the climate change scenarios for 2010-2050 indicated a faster increase of daily temperature maxima over Nordeste compared to that simulated for the recent past

In this paper, soil carbon, nitrogen and phosphorus concentrations and stocks were investigated in agricultural and natural areas in 17 plot-level paired sites and in a regional survey encompassing more than 100 pasture soils In the paired sites, elemental soil concentrations and stocks were determined in native vegetation (forests and savannas), pastures and crop-livestock systems (CPSs). Nutrient stocks were calculated for the soil depth intervals 0-10, 0-30, and 0-60 cm for the paired sites and 0-10, and 0-30 cm for the pasture regional survey by sum stocks obtained in each sampling intervals (0-5, 5-10, 10-20, 20-30, 30-40, 40-60 cm). Overall, there were significant differences in soil element concentrations and ratios between different land uses, especially in the surface soil layers. Carbon and nitrogen contents were lower, while phosphorus contents were higher in the pasture and CPS soils than in native vegetation soils. Additionally, soil stoichiometry has changed with changes in land use. The soil C :N ratio was lower in the native vegetation than in the pasture and CPS soils, and the carbon and nitrogen to available phosphorus ratio (PME/ decreased from the native vegetation to the pasture to the CPS soils. In the plotlevel paired sites, the soil nitrogen stocks were lower in all depth intervals in pasture and in the CPS soils when compared with the native vegetation soils. On the other hand, the soil phosphorus stocks were higher in all depth intervals in agricultural soils when compared with the native vegetation soils. For the regional pasture survey, soil nitrogen and phosphorus stocks were lower in all soil intervals in pasture soils than in native vegetation soils. The nitrogen loss with cultivation observed here is in line with other studies and it seems to be a combination of decreasing organic matter inputs, in cases where crops replaced native forests, with an increase in soil organic matter decomposition that leads to a decrease in the long run. The main cause of the increase in soil phosphorus stocks in the CPS and pastures of the plot-level paired site seems to be linked to phosphorus fertilization by mineral and organics fertilizers. The findings of this paper illustrate that land-use changes that are currently common in Brazil alter soil concentrations, stocks and elemental ratios of carbon, nitrogen and phosphorus. These changes could have an impact on the subsequent vegetation, decreasing soil carbon and increasing nitrogen limitation but alleviating soil phosphorus deficiency.

O PAIS é uma tecnologia social criada para desenvolver a agricultura familiar por meio de padrões agroecológicos, integrando em um mesmo sistema a criação de animais e produção de hortaliças, frutas, cereais e adubação por compostagem. Agricultores em diversas regiões do país têm recebido unidades do PAIS através da iniciativa do SEBRAE, Fundação Banco do Brasil e o Ministério da Integração Nacional. Apesar da propagação desta tecnologia há uma grande disparidade em relação ao desempenho desse sistema entre as unidades implantadas. O presente artigo faz uma análise dos principais fatores que contribuem para o desenvolvimento da tecnologia social PAIS, tendo por base, estudos realizados em 24 unidades no município de Macaíba, região metropolitana de Natal, RN, distribuídas em quatro comunidades Através do método comparativo foi possível observar que duas comunidades houve desistência da produção pelo PAIS e em outras duas há uma produção crescente de alimentos através desse sistema. Os resultados demonstram que, os fatores que mais influenciaram na desistência ou permanência dos agricultores na produção com o PAIS foram aspectos relacionadas ao nível de organização comunitária, pois as comunidades onde os agricultores tinham uma maior entrosamento social foram as que conseguiram continuar com a manutenção das unidades do PAIS, por outro lado, nas comunidades onde houveram desistências foi notado um menor grau de coesão social entre eles.

Criado em 2005, o Agroamigo adota metodologia diferenciada para alcançar e oferecer tratamento adequado a agricultores familiares pobres da área de atuação do BNB, visando suprir as dificuldades observadas no Pronaf B. Em 2012, o Agroamigo expandiu seu público-alvo para além do Pronaf B. Em função disso, este artigo verifica se, a despeito de tal expansão, o programa continua privilegiando aquele público inicial. Analisam-se dados de um cadastro socioeconômico levantados por assessores de microcrédito do Programa, durante visitas prévias ao financiamento, com recorte temporal para o período de sua expansão, 2012-2014. Confrontam-se tais informações com dados sobre público-alvo do Pronaf b. Verificou-se precariedade no acesso à infraestrutura de produção, mas avanços em relação à participação feminina e à bancarização. A produção concentra-se na atividade pecuária, comercializam-se os produtos preferencialmente nos mercados locais, de forma individual, diretamente para os consumidores e a renda media total obtida não ultrapassa R$ 20 mil anuais. Conclui-se que, apesar da ampliação para outros públicos, o Agroamigo segue priorizando o agricultor enquadrado no Pronaf B, com a ressalva de que a base de clientes ampliada cobre apenas três anos de operacionalização, requerendo uma avaliação futura para confirmação.

The use of the extraordinary hydroelectric potential of the Amazon Basin originated an increase in the offer of renewable energy in Brazil, which, in its turn, leads to conflicts and a lack of consensus among different players owing to the potential negative impacts related to the construction and operation of large hydroelectric power plants in relatively well preserved areas. In this context, environmental licensing is one of the national environmental policy’s main instruments for making decisions regarding the use of the hydroelectric potential, especially the rivers of the Amazon Basin. Nevertheless, this significant instrument has its limitations and requires adjustments in order to better aid the decision making process regarding the use of water resources and land with the goal of increasing the offer of electric energy.

Generalized Renewal Processes are useful for approaching the rejuvenation of dynamical systems resulting from planned or unplanned interventions. We present new perspectives for the Generalized Renewal Processes in general and for the Weibull-based Generalized Renewal Processes in particular. Disregarding from literature, we present a mixed Generalized Renewal Processes approach involving Kijima Type I and II models, allowing one to infer the impact of distinct interventions on the performance of the system under study. The first and second theoretical moments of this model are introduced as well as its maximum likelihood estimation and random sampling approaches. In order to illustrate the usefulness of the proposed Weibull-based Generalized Renewal Processes model, some real data sets involving improving, stable, and deteriorating systems are used.