Publicações

Debates on climate change, energy and food security concerns have underscored the need for new methods and tools to explore and understand the complexity of these relevant issues. In this study, we used unsupervised probabilistic modeling-latent Dirichlet allocation (LDA)-to examine the changes in social policy debates related to ethanol production in Brazil and its relationship with climate change and food security. We analyze a large amount of data obtained from Brazilian newspapers, government and business documents, and the bulletins of nongovernmental organizations and social movements from 2007 through 2017. The results from the LDA application allowed us to identify key topics, detect novel trends, and follow them through time, in addition to exhibiting the limitations encountered in identifying social actor discourses. To overcome these limitations, we combine LDA and discourse analysis to enable the construction of topics, concepts, and discourses of the actors surrounding the issue of this study. The findings verify the utility of these techniques by emphasizing the themes and discourses of the actors involved and by identifying the determinant positions of the Brazilian actors in the discussions on ethanol production and its competition with food security and the contributions of ethanol as a renewable energy source to mitigate climate change. This finding provides insights for water-energy-food nexus research.

The current debate on corporate social responsibility was triggered by the understanding that companies should be responsible for mitigating the impacts of their activities on the society and the environment. In this paper, drawing on the structural power of business, we examine the rule-setting power in which sugarcane ethanol companies engage, and then discuss why these companies develop and use institutions to promote sustainability. We use a machine learning algorithm, latent Dirichlet allocation, to identify companies’ commitment to sustainability and business-led governance by analyzing a large volume of data from public corporate documents. The results reveal 36 main themes that demonstrate the rule-setting power of the sugarcane ethanol industry through voluntary standards, codes of conduct, and corporate social responsibility these companies use as indicators of superior social and environmental performance and to show sustainability is embedded in companies’ priorities. However, the results also show critical issues of unsustainable production practices can affect industry image and stress socio-environmental relationships. These issues can be ameliorated with integrative governance that considers the independence of the sectors involved in ethanol production.

The hydrology of the Brazilian Pantanal, part of the largest humid tropical area on the planet, follows the rhythm of seasonal floods. The traditional movement of cattle herds in the southern Pantanal is defined by these seasonal flooding patterns, which determine the availability and quality of native-grass pastures throughout the year. Extreme hydrological events, such as prolonged droughts and intense floods, can impact the management of cattle in this region, preventing access to, circulation within, and occupation of some grazing areas. This study aims to analyze the spatial and temporal variability of precipitation, the river levels in this region from 1974 to 2012, and assessed the effects on the evolution of local beef cattle stocks. We integrated the spatiotemporal variability of precipitation and river levels for six gaging stations and standardized these variables using standard deviation and linear trends at annual and seasonal scales. Additionally, we integrated the results with an analysis of the livestock production within the regions municipalities. Regional precipitation was highly variable, including an almost decadal oscillation, with positive trends in parts of the 1970s and 1980s and a negative trend since the 1990s. River levels in the northern portion of the basin and in the Paraguay River corresponded to those dynamics while presenting marked anomalies. Simultaneously, river levels in the eastern Pantanal changed from negative to positive anomalies, which were more intense in wet months. Both the eastern and western patterns reflected the occurrence of extreme El NiñoSouthern Oscillation events and other large-scale climatic patterns. In intra-annual terms, the variability of the river levels during the flooded months at four of the six gaging stations studied suggests an early onset or delay of the flood season, as well as positive anomalies in the ebbing months and in the southeast. Given the lags in flow between different rivers in the region, this behavior draws attention to dam construction and intensification of localized flooding in the southern areas, which may impact everyday life and cattle management. For example, from 2009 to 2012, two severe droughts and an extreme flood significantly impacted livestock numbers in the region. Overall, herd numbers decreased (increased) in humid (dry) periods, including a reduction of over 1 million head during the flood of 19731974. The differential level patterns at annual, wet season, and dry season between the eastern and western sides of the Pantanal modulate the livestock activities, where the strong negative anomalies of the levels along the eastern side seem to force the diminution of beef cattle stock at local regions in different intensities in annual scale. This reinforces the effects of climate variability and extreme hydrological events on the management and dynamics of the beef cattle industry and market in Brazil.

Pantanal is one of the largest wetlands in the world. In its southern portion, it hosts significant beef cattle ranching, having a herd of 4,832,200 head of cattle in 2016 (IBGE, 2018). Yet it presents intra-regional differences and complementarities. This article discusses such current territory definition, focusing on cattle ranching in Pantanal, considering its forms of occupation, agents, and its intra-regional flow of cattle. This recognition is essential for the identification of the arrangements developed in the territory, its temporal dynamics and spatial strategies, assuming different forms of interaction with the environment. In order to identify multiple livestock territories and their logics of action, data grouped into four dimensions were considered: (i) agents, (ii) product, (iii) space used, and (iv) flows and circulation, approached in different scales (farms, municipal and units of landscape floodplain/plateau). The analyzes show different forms of domination and territorial appropriation, continuous and discontinuous, permanent and temporary. Mapping of cattle territories in the South Pantanal identified a scenario of multiterritoriality. While maintaining its nursery profile, it presents more intensive arrangements with the rearing and fattening phases. New territorialities represented by external agents and the fragmentation of old properties has genereted a new mapping of the used spaces for cattle breeding and posed new challenges for the maintenance of the traditional cattle production systems in the region.

Tropical carbon emissions are largely derived from direct forest clearing processes. Yet, emissions from drought-induced forest fires are, usually, not included in national-level carbon emission inventories. Here we examine Brazilian Amazon drought impacts on fire incidence and associated forest fire carbon emissions over the period 20032015. We show that despite a 76% decline in deforestation rates over the past 13 years, fire incidence increased by 36% during the 2015 drought compared to the preceding 12 years. The 2015 drought had the largest ever ratio of active fire counts to deforestation, with active fires occurring over an area of 799,293 km2. Gross emissions from forest fires (989 ± 504 Tg CO2 year−1 ) alone are more than half as great as those from old-growth forest deforestation during drought years. We conclude that carbon emission inventories intended for accounting and developing policies need to take account of substantial forest fire emissions not associated to the deforestation process.

Climate change has been identified as the primary threat to the integrity and functioning of ecosystems in this century, although there is still much uncertainty about its effects and the degree of vulnerability for different ecosystems to this threat. Here we propose a new methodological approach capable of measuring and mapping the resilience of terrestrial ecosystems at large scales based on their climatic niche. To do this, we used high spatial resolution remote sensing data and ecological niche modeling techniques to calculate and spatialize the resilience of three stable states of ecosystems in South America: forest, savanna, and grassland. Also, we evaluated the sensitivity of ecosystems to climate stress, the likelihood of exposure to non-analogous climatic conditions, and their respective adaptive capacities in the face of climate change. Our results indicate that forests, the most productive and biodiverse terrestrial ecosystems on the earth, are more vulnerable to climate change than savannas or grasslands. Forests showed less resistance to climate stress and a higher chance of exposure to non-analogous climatic conditions. If this scenario occurs, the forest ecosystems would have less chance of adaptation compared to savannas or grasslands because of their narrow climate niche. Therefore, we can conclude that a possible consolidation of non-analogous climatic conditions would lead to a loss of resilience in the forest ecosystem, significantly increasing the chance of a critical transition event to another stable state with a lower density of vegetation cover (e.g., savanna or grassland).

Very few studies have been devoted to understanding the digital terrain model (DTM) creation for Amazon forests. DTM has a special and important role when airborne laser scanning is used to estimate vegetation biomass. We examined the influence of pulse density, spatial resolution, filter algorithms, vegetation density and slope on the DTM quality. Three Amazonian forested areas were surveyed with airborne laser scanning, and each original point cloud was reduced targeting to 20, 15, 10, 8, 6, 4, 2, 1, 0.75, 0.5 and 0.25 pulses per square meter based on a random resampling process. The DTM from resampled clouds was compared with the reference DTM produced from the original LiDAR data by calculating the deviation pixel by pixel and summarizing it through the root mean square error (RMSE). The DTM from resampled clouds were also evaluated considering the level of agreement with the reference DTM. Our study showed a clear trade-off between the return density and the horizontal resolution. Higher forest canopy density demanded higher return density or lower DTM resolution.

High ozone (O-3) concentrations are a major concern about air quality in the Sao Paulo Metropolitan Area (SPMA). During 2016, the 8-hour state standard of 140 mu g m(-3) was exceeded on 32 days, whereas the 1-hour national standard of 160 mu g m(-3) was exceeded on 76 days. Exposure to such unhealthy O-3 levels and other pollutants can lead to respiratory disease. The focus of this study is to determine the main O-3 precursor in terms of the volatile organic compounds (VOCs) in order to provide a scientific basis for controlling this pollutant. In this work, 66 samples of hydrocarbons, 62 of aldehydes and 42 of ethanol were taken during the period from September 2011 to August 2012 from 7:00 to 9:00 a.m. The OZIPR trajectory model and SAPRC atmospheric chemical mechanism were used to determine the major O-3 precursors. During the studied period, aldehydes represented 35.3% of the VOCs, followed by ethanol (22.6%), aromatic compounds (15.7%), alkanes (13.5%), ketones (6.8%), alkenes (6.0%) and alkadienes (less than 0.1%). Considering the concentration of VOCs and their typical reactivity, the simulation results showed that acetaldehyde contributed 61.2% of the O-3 formation. The total aldehydes contributed 74%, followed by aromatics (14.5%), alkenes (10.2%), alkanes (1.3%) and alkadienes (e.g., isoprene; 0.03%). Simulation results for the SPMA showed that the most effective alternative for limiting the O-3 levels was reducing the VOC emissions, mainly the aldehydes.

In 2017, the dominant greenhouse gases released into Earth’s atmosphere-carbon dioxide, methane, and nitrous oxide-reached new record highs. The annual global average carbon dioxide concentration at Earth’s surface for 2017 was 405.0 ± 0.1 ppm, 2.2 ppm greater than for 2016 and the highest in the modern atmospheric measurement record and in ice core records dating back as far as 800 000 years. The global growth rate of CO2 has nearly quadrupled since the early 1960s. With ENSO-neutral conditions present in the central and eastern equatorial Pacific Ocean during most of the year and weak La Niña conditions notable at the start and end, the global temperature across land and ocean surfaces ranked as the second or third highest, depending on the dataset, since records began in the mid-to-late 1800s. Notably, it was the warmest non-El Niño year in the instrumental record. Above Earth’s surface, the annual lower tropospheric temperature was also either second or third highest according to all datasets analyzed. The lower stratospheric temperature was about 0.2°C higher than the record cold temperature of 2016 according to most of the in situ and satellite datasets. Several countries, including Argentina, Uruguay, Spain, and Bulgaria, reported record high annual temperatures. Mexico broke its annual record for the fourth consecutive year. On 27 January, the temperature reached 43.4°C at Puerto Madryn, Argentina-the highest temperature recorded so far south (43°S) anywhere in the world. On 28 May in Turbat, western Pakistan, the high of 53.5°C tied Pakistan’s all-time highest temperature and became the world-record highest temperature for May. In the Arctic, the 2017 land surface temperature was 1.6°C above the 1981-2010 average, the second highest since the record began in 1900, behind only 2016. The five highest annual Arctic temperatures have all occurred since 2007. Exceptionally high temperatures were observed in the permafrost across the Arctic, with record values reported in much of Alaska and northwestern Canada. In August, high sea surface temperature (SST) records were broken for the Chukchi Sea, with some regions as warm as +11°C, or 3° to 4°C warmer than the longterm mean (1982-present). According to paleoclimate studies, today’s abnormally warm Arctic air and SSTs have not been observed in the last 2000 years. The increasing temperatures have led to decreasing Arctic sea ice extent and thickness. On 7 March, sea ice extent at the end of the growth season saw its lowest maximum in the 37-year satellite record, covering 8% less area than the 1981-2010 average. The Arctic sea ice minimum on 13 September was the eighth lowest on record and covered 25% less area than the long-term mean. Preliminary data indicate that glaciers across the world lost mass for the 38th consecutive year on record; the declines are remarkably consistent from region to region. Cumulatively since 1980, this loss is equivalent to slicing 22 meters off the top of the average glacier. Antarctic sea ice extent remained below average for all of 2017, with record lows during the first four months. Over the continent, the austral summer seasonal melt extent and melt index were the second highest since 2005, mostly due to strong positive anomalies of air temperature over most of the West Antarctic coast. In contrast, the East Antarctic Plateau saw record low mean temperatures in March. The year was also distinguished by the second smallest Antarctic ozone hole observed since 1988. Across the global oceans, the overall long-term SST warming trend remained strong. Although SST cooled slightly from 2016 to 2017, the last three years produced the three highest annual values observed; these high anomalies have been associated with widespread coral bleaching. The most recent global coral bleaching lasted three full years, June 2014 to May 2017, and was the longest, most widespread, and almost certainly most destructive such event on record. Global integrals of 0-700-m and 0-2000-m ocean heat content reached record highs in 2017, and global mean sea level during the year became the highest annual average in the 25-year satellite altimetry record, rising to 77 mm above the 1993 average. In the tropics, 2017 saw 85 named tropical storms, slightly above the 1981-2010 average of 82. The North Atlantic basin was the only basin that featured an above-normal season, its seventh most active in the 164-year record. Three hurricanes in the basin were especially notable. Harvey produced record rainfall totals in areas of Texas and Louisiana, including a storm total of 1538.7 mm near Beaumont, Texas, which far exceeds the previous known U.S. tropical cyclone record of 1320.8 mm. Irma was the strongest tropical cyclone globally in 2017 and the strongest Atlantic hurricane outside of the Gulf of Mexico and Caribbean on record with maximum winds of 295 km h-1. Maria caused catastrophic destruction across the Caribbean Islands, including devastating wind damage and flooding across Puerto Rico. Elsewhere, the western North Pacific, South Indian, and Australian basins were all particularly quiet. Precipitation over global land areas in 2017 was clearly above the long-term average. Among noteworthy regional precipitation records in 2017, Russia reported its second wettest year on record (after 2013) and Norway experienced its sixth wettest year since records began in 1900. Across India, heavy rain and flood-related incidents during the monsoon season claimed around 800 lives. In August and September, above-normal precipitation triggered the most devastating floods in more than a decade in the Venezuelan states of Bolívar and Delta Amacuro. In Nigeria, heavy rain during August and September caused the Niger and Benue Rivers to overflow, bringing floods that displaced more than 100 000 people. Global fire activity was the lowest since at least 2003; however, high activity occurred in parts of North America, South America, and Europe, with an unusually long season in Spain and Portugal, which had their second and third driest years on record, respectively. Devastating fires impacted British Columbia, destroying 1.2 million hectares of timber, bush, and grassland, due in part to the region’s driest summer on record. In the United States, an extreme western wildfire season burned over 4 million hectares; the total costs of 18 billion tripled the previous U.S. annual wildfire cost record set in 1991.