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Land-use changes are critical for climate policy because native vegetation and soils store abundant carbon and their losses from agricultural expansion, together with emissions from agricultural production, contribute about 20 to 25 per cent of greenhouse gas emissions1,2. Most climate strategies require maintaining or increasing land-based carbon3 while meeting food demands, which are expected to grow by more than 50 per cent by 20501,2,4. A finite global land area implies that fulfilling these strategies requires increasing global land-use efficiency of both storing carbon and producing food. Yet measuring the efficiency of land-use changes from the perspective of greenhouse gas emissions is challenging, particularly when land outputs change, for example, from one food to another or from food to carbon storage in forests. Intuitively, if a hectare of land produces maize well and forest poorly, maize should be the more efficient use of land, and vice versa. However, quantifying this difference and the yields at which the balance changes requires a common metric that factors in different outputs, emissions from different agricultural inputs (such as fertilizer) and the different productive potentials of land due to physical factors such as rainfall or soils. Here we propose a carbon benefits index that measures how changes in the output types, output quantities and production processes of a hectare of land contribute to the global capacity to store carbon and to reduce total greenhouse gas emissions. This index does not evaluate biodiversity or other ecosystem values, which must be analysed separately. We apply the index to a range of land-use and consumption choices relevant to climate policy, such as reforesting pastures, biofuel production and diet changes. We find that these choices can have much greater implications for the climate than previously understood because standard methods for evaluating the effects of land use4-11 on greenhouse gas emissions systematically underestimate the opportunity of land to store carbon if it is not used for agriculture.

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Este estudo verificou o nível de glicerina bruta em substituição total do óleo de soja e parcial do milho em dietas de juvenis de tambaqui sem que o ingrediente interfira no desempenho zootécnico desses animais. O trabalho foi realizado na Universidade Federal do Tocantins, avaliando cinco níveis de inclusão da glicerina bruta (0%; 7,5%; 10%; 12,5% e 15%) em três repetições com 10 animais cada (n=150 tambaquis). Esses animais foram alimentados com as rações experimentais por um período de 75 dias (15 dias de adaptação e 60 dias experimentais). Ao final desse período, os animais foram contidos para a mensuração dos valores do desempenho zootécnico dos animais (taxa de crescimento específico, conversão alimentar aparente, eficiência alimentar, índice hepatossomático, ganho de peso e fator de condição). Durante o período experimental, não houve mortalidade, e de todos os índices avaliados apenas no fator de condição do animal ocorreu diferença estatística, quando se comparou o período inicial e o final do experimento. A inclusão de até 15% de glicerina bruta em dietas de tambaqui em substituição total do óleo de soja e parcial do milho pode ser realizada sem que prejudique o desempenho zootécnico da espécie estudada.(AU)

This study examined the level of crude glycerin in total replacement of soybean oil and partial replacement of corn in diets for tambaqui without ingredient interfering on the growth performance of these animals. The study was conducted at the Federal University of Tocantins, evaluating five levels of crude glycerin inclusion (0%, 7.5%, 10%, 12.5%, and 15%) in 3 replicates with 10 animals each (n = 150 tambaqui.) These animals were fed the experimental diets for a period of 75 days (15 days of adaptation and 60 days of trial), at the end of this period the animals were restrained to measure the values of the growth performance of animals (Specific growth rate, apparent food conversion, feed efficiency, hepatosomatic index, weight gain, and condition factor). During the study period, there were no deaths and in all indices evaluated, only the animal's condition factor presented statistical difference when comparing the initial and final periods of the experiment. The inclusion of up to 15% crude glycerin in tambaqui diets in total replacement of soybean oil and partial replacement of corn can be used without prejudice to the growth performance of the species studied.(AU)

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Glicerina é um líquido adocicado, higroscópico, inodoro, viscoso, energético, contendo variáveis níveis de glicerol, sendo utilizado como nutriente glicogênico ou lipogênico, dependendo da condição energética do animal. O glicerol ou 1,2,3-propanotriol é pertencente a função álcool, com três hidroxilas, de fórmula molecular C3H8O3. Em suínos, altos níveis de inclusão de glicerina podem proporcionar baixo conteúdo energético, pois o sistema enzimático da glicerol quinase torna-se saturado na conversão do glicerol para glicerol-3-fosfato, sendo o excesso excretado pela urina. A matéria-prima é um dos fatores que mais influenciam na composição da glicerina, podendo ser produzida a partir de óleo de soja, sebo bovino, gordura amarela e gordura de aves. Os componentes com maior participação na composição são glicerol, água e lipídios, contudo as limitações de seu uso na alimentação animal estão ligadas aos níveis residuais de sódio, potássio, metanol e umidade. Os níveis de glicerina bruta mais indicados para a viabilidade técnica e econômica estão em torno de 10%, sendo que acima de 15% compromete o desempenho e a viabilidade econômica. Por possuir características favoráveis e teores de energia em torno de 3.579 kcal/kg de energia metabolizável, a glicerina pode ser utilizada como ingrediente energético em rações para suínos.

Glycerin is a sweet, hygroscopic, odorless, viscous, energetic liquid containing variable glycerol levels being used as glycogen or lipogenic nutrient, depending on the energy condition of the animal. Glycerol, or 1,2,3-propanetriol, belongs to the alcohol group, with three hydroxyls, and the molecular formula of C3H8O3. In pigs, the inclusion of high levels of glycerin can provide low energy content, since the enzyme system in glycerol kinase becomes saturated in the conversion of glycerol to glycerol-3-phosphate, with the excess being excreted in the urine. The feedstock is one of the factors that most influence the composition of glycerin, which may be produced from soybean oil, beef tallow, yellow grease, and poultry fat. The components with the highest involvement in the composition are glycerol, water and lipids, however, the limitations of use in animal feed are connected to residual levels of sodium, potassium, methanol and humidity. Crude glycerin levels better suited to the technical and economic viability are at approximately 10%, while compromising the performance and economic viability if above 15%. Since it has favorable characteristics and energy levels around 3.579 kcal/kg of metabolizable energy, glycerin can be used as an energy ingredient in pig feed.

La glicerina es un líquido dulce, higroscópico, inodoro, viscoso, energético, que contiene niveles de glycerol variables, que se utililiza como nutriente glicogénico o lipogénico, dependiendo de la condición de energía del animal. El glicerol o 1, 2, 3 ­ propanotriol, es perteneciente a función alcohol, con tres hidroxilas, de formula molecular C3H8O3. En cerdos, los altos niveles de inclusión de glicerina pueden proporcionar un bajo contenido energético, pues el sistema enzimático de glicerol quinase se hace saturado en la conversión de glicerol en glicerol-3-fosfato, siendo el exceso excretado por la orina. La materia prima es uno de los factores que más influyen en la composición de la glicerina, pudiendo ser producida a partir del aceite de soja, sebo de ganado, grasa amarilla y grasa de aves. Los componentes con mayor participación en la composición son glicerol, agua y lepidios, sin embargo, las limitaciones de su uso en la alimentación animal están conectadas a niveles residuales de sodio, potasio, metanol y humedad. Los niveles de glicerina cruda más adecuados para la viabilidad técnica y económica están alrededor de 10%, siendo que más de 15% compromete el rendimiento y la viabilidad económica. Por tener características favorables y niveles de energía alrededor de 3579 kcal/kg de energía metabolizable, la glicerina puede ser utilizada como ingrediente de energía en alimentación de cerdos.

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This work assessed the environmental impacts of the production and use of 1 MJ of hydrous ethanol (E100) in Brazil in prospective scenarios (2020-2030), considering the deployment of technologies currently under development and better agricultural practices. The life cycle assessment technique was employed using the CML method for the life cycle impact assessment and the Monte Carlo method for the uncertainty analysis. Abiotic depletion, global warming, human toxicity, ecotoxicity, photochemical oxidation, acidification, and eutrophication were the environmental impacts categories analyzed. Results indicate that the proposed improvements (especially no-til farming-scenarios s2 and s4) would lead to environmental benefits in prospective scenarios compared to the current ethanol production (scenario s0). Combined first and second generation ethanol production (scenarios s3 and s4) would require less agricultural land but would not perform better than the projected first generation ethanol, although the uncertainties are relatively high. The best use of 1 ha of sugar cane was also assessed, considering the displacement of the conventional products by ethanol and electricity. No-til practices combined with the production of first generation ethanol and electricity (scenario s2) would lead to the largest mitigation effects for global warming and abiotic depletion. For the remaining categories, emissions would not be mitigated with the utilization of the sugar cane products. However, this conclusion is sensitive to the displaced electricity sources.

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Marginal agricultural land is estimated for biofuel production in Africa, China, Europe, India, South America, and the continental United States, which have major agricultural production capacities. These countries/regions can have 320-702 million hectares of land available if only abandoned and degraded cropland and mixed crop and vegetation land, which are usually of low quality, are accounted. If grassland, savanna, and shrubland with marginal productivity are considered for planting low-input high-diversity (LIHD) mixtures of native perennials as energy crops, the total land availability can increase from 1107-1411 million hectares, depending on if the pasture land is discounted. Planting the second generation of biofuel feedstocks on abandoned and degraded cropland and LIHD perennials on grassland with marginal productivity may fulfill 26-55% of the current world liquid fuel consumption, without affecting the use of land with regular productivity for conventional crops and without affecting the current pasture land. Under the various land use scenarios, Africa may have more than one-third, and Africa and Brazil, together, may have more than half of the total land available for biofuel production. These estimations are based on physical conditions such as soil productivity, land slope, and climate.

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OBJECTIVE: To determine whether respiratory symptoms and chronic bronchitis are associated with the use of biomass fuels (BMFs) among women residing in rural areas of the Ekiti State, in southwestern Nigeria. METHODS: From January to June of 2009, we carried out a cross-sectional study including 269 adult women. To collect data on sociodemographic status, type of fuel used for cooking in the household, respiratory symptoms, and smoking history, we used a questionnaire adapted from the European Community Respiratory Health Survey. All of the participants were invited to undergo spirometry. RESULTS: Of the 269 women in the study, 161 (59.9%) used BMFs for cooking. The proportion of women who reported respiratory symptoms was greater among those using BMFs than among those using a non-BMF-cough (13.7% vs. 3.7%); wheezing (8.7% vs. 2.8%); chest pain (7.5% vs. 1.9%); breathlessness (11.8% vs. 6.5%); nasal symptoms (9.3% vs. 4.6%); and chronic bronchitis (10.6% vs. 2.8%). Multivariate logistic regression analysis revealed that the use of BMFs was associated with the following variables: cough (OR = 4.82; p = 0.01); chronic bronchitis (OR = 3.75; p = 0.04); wheezing (OR = 2.22; p = 0.23); chest pain (OR = 3.82; p = 0.09); breathlessness (OR = 1.54; p = 0.35); and nasal symptoms (OR = 2.32; p = 0.20). All of the spirometric parameters evaluated (FEV1, FVC, FEV1/FVC ratio, and PEF) were lower in the women using BMFs than in those using a non-BMF. CONCLUSIONS: Our results underscore the need for women using BMFs in their households to replace them with a nontoxic type of fuel, such as electricity or gas.

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OBJETIVO: Determinar a associação de sintomas respiratórios e bronquite crônica com o uso de biocombustíveis entre mulheres habitantes de áreas rurais do estado de Ekiti, sudoeste da Nigéria. MÉTODOS: De janeiro a junho de 2009, realizou-se um estudo transversal com uma amostra de 269 mulheres adultas. Um questionário adaptado do European Community Respiratory Health Survey foi aplicado para a obtenção de dados sobre características sociodemográficas, tipo de combustível utilizado para a preparação de alimentos, sintomas respiratórios e história de tabagismo. Todas as participantes foram convidadas a realizar espirometria. RESULTADOS: Das 269 mulheres no estudo, 161 (59,9 por cento) utilizavam biocombustíveis para a preparação de alimentos. As mulheres que utilizavam biocombustíveis relataram mais sintomas respiratórios que aquelas que não os utilizavam - tosse (13,7 por cento vs. 3,7 por cento); sibilância (8,7 por cento vs. 2,8 por cento); dor no peito (7,5 por cento vs. 1,9 por cento); falta de ar (11,8 por cento vs. 6,5 por cento); sintomas nasais (9,3 por cento vs. 4,6 por cento); e bronquite crônica (10,6 por cento vs. 2,8 por cento). A análise multivariada por regressão logística confirmou que o uso de biocombustíveis está associado às seguintes variáveis: tosse (OR = 4,82; p = 0,01); bronquite crônica (OR = 3,75; p = 0,04); sibilância (OR = 2,22; p = 0,23); dor no peito (OR = 3,82; p = 0,09); falta de ar (OR = 1,54; p = 0,35); e sintomas nasais (OR = 2,32; p = 0,20). Todos os parâmetros espirométricos avaliados (VEF1, CVF, VEF1/CVF e PFE) foram menores nas mulheres que utilizavam biocombustíveis do que naquelas que não os utilizavam. CONCLUSÕES: Nossos resultados enfatizam a necessidade de se substituir o uso de biocombustíveis nos domicílios pelo de um tipo de combustível atóxico, como eletricidade ou gás.

OBJECTIVE: To determine whether respiratory symptoms and chronic bronchitis are associated with the use of biomass fuels (BMFs) among women residing in rural areas of the Ekiti State, in southwestern Nigeria. METHODS: From January to June of 2009, we carried out a cross-sectional study including 269 adult women. To collect data on sociodemographic status, type of fuel used for cooking in the household, respiratory symptoms, and smoking history, we used a questionnaire adapted from the European Community Respiratory Health Survey. All of the participants were invited to undergo spirometry. RESULTS: Of the 269 women in the study, 161 (59.9 percent) used BMFs for cooking. The proportion of women who reported respiratory symptoms was greater among those using BMFs than among those using a non-BMF-cough (13.7 percent vs. 3.7 percent); wheezing (8.7 percent vs. 2.8 percent); chest pain (7.5 percent vs. 1.9 percent); breathlessness (11.8 percent vs. 6.5 percent); nasal symptoms (9.3 percent vs. 4.6 percent); and chronic bronchitis (10.6 percent vs. 2.8 percent). Multivariate logistic regression analysis revealed that the use of BMFs was associated with the following variables: cough (OR = 4.82; p = 0.01); chronic bronchitis (OR = 3.75; p = 0.04); wheezing (OR = 2.22; p = 0.23); chest pain (OR = 3.82; p = 0.09); breathlessness (OR = 1.54; p = 0.35); and nasal symptoms (OR = 2.32; p = 0.20). All of the spirometric parameters evaluated (FEV1, FVC, FEV1/FVC ratio, and PEF) were lower in the women using BMFs than in those using a non-BMF. CONCLUSIONS: Our results underscore the need for women using BMFs in their households to replace them with a nontoxic type of fuel, such as electricity or gas.

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