trabalho completo - 52ª Reunião Anual da Sociedade Brasileira de
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trabalho completo - 52ª Reunião Anual da Sociedade Brasileira de
52a Reunião Anual da Sociedade Brasileira de Zootecnia Zootecnia: Otimizando Recursos e Potencialidades Belo Horizonte – MG, 19 a 23 de Julho de 2015 Influência do aquecimento global sobre as variáveis climatológicas e índice de conforto térmico no estado da Paraíba Bonifácio Benício de Souza1, Gustavo de Assis Silva2, Elisângela Maria Nunes da Silva3 1 Zootecnista, Professor Associado - UAMV/CSTR/UFCG – Campus de Patos-PB. E-mail: [email protected] 2 Aluno do Programa de Pós-graduação em Medicina Veterinária – UFCG, Patos, Paraíba. Extensionista rural do IPA. 3 Pós-Doutoranda em Medicina Veterinária – UFCG, Patos, Paraíba. Bolsista CNPq Resumo: O objetivo deste trabalho foi avaliar o efeito do aquecimento global sobre as variáveis climatológicas e índice de conforto térmico no estado da Paraíba. Foram coletadas os dados climatológicos e calculados o índice de temperatura e umidade em quatro estações meteorológicas distribuídas por todo estado no período das normais de 1961-1990 e nos últimos quatro anos 2011-2015. Houve aumento em todas as regiões do estado para a temperatura ambiente e o ITU. Concluiu-se que todas as regiões do estado da Paraíba estão sofrendo alterações climáticas em decorrência do efeito estufa e que o estresse térmico demonstrado pelo ITU, indica que mudanças de atitudes deverão ser intensificadas para possibilitar a sobrevivência e melhorar a produção animal em todo estado. Palavras-chave: temperatura, clima, efeito estufa, Paraíba Global warming influence on the weather and thermal comfort index in the state of Paraiba Abstract: The objective of this study was to evaluate the effect of global warming on the weather and thermal comfort index in the state of Paraíba. Climatological data were collected and calculated the temperature humidity index in four weather stations distributed throughout the state in the period of the normal 1961-1990 and the last four years from 2011 to 2015. There was an increase in all regions of the state to room temperature and the THI. It was concluded that all of Paraíba state regions are suffering from climate change due to the greenhouse effect and the heat stress demonstrated by the ITU indicates that attitude changes should be intensified to enable the survival and improve animal production in every state. Keywords: temperature, climate, greenhouse effect, Paraíba Introduction In recent decades the world has experienced many disasters resulting from rapid climate change with devastating effects. The increase in the concentration of greenhouse gases originated from burning fossil fuels has been identified as the main cause of global climate change resulting from the greenhouse effect in the Earth's atmosphere. According to the consolidated climate projections in the fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC), the global mean air temperature must continually increase over the twenty-first century (Meehl et al. 2007). According to Lucena (2010) global climate change can generate impacts on natural and human systems, making it necessary to investigate potential vulnerabilities and adaptation options. Among the climatic variables that most influence the lives of warm-blooded animals to room temperature and relative humidity are the ones that stand out, since together, these variables directly affect the evaporative heat loss, affecting thermoregulation and thus, the performance and animal production. Therefore, the aim with this study was to evaluate the effect of global warming on the weather and thermal comfort index in the state of Paraiba, Brazil semi-arid. Materials and Methods The study was conducted in the state of Paraiba, from the get meteorological data from the database for research and education (BDMEP, INMET) four weather stations distributed by the state, located in the following cities and regions: Campina Grande (Agreste) João Pessoa (Litoral), Monteiro (Cariri) and Sao Goncalo (High Hinterland). Environmental variables dry bulb temperature (DBT), relative humidity (RH), rainfall (PP) were studied in the periods (1961-1990) and (2011-2015) and the temperature humidity index (THI) It was calculated using the equation proposed by Thom (1959), as described below. THI = dbt + 0,36 tpo + 0,42 onde: dbt = dry bulb temperature ºC e dpt= dew point temperature ºC. The means were analyzed _______________________________________________________________________________________________________________________________ Página - 1 - de 3 52a Reunião Anual da Sociedade Brasileira de Zootecnia Zootecnia: Otimizando Recursos e Potencialidades Belo Horizonte – MG, 19 a 23 de Julho de 2015 from the difference between the normal period of 30 years (1961-1990) and the period of the last four years (2011-2015). The values obtained allowed to determine climate changes that occurred in Paraíba due to global warming by the action of greenhouse gases. Results and Discussion Based on the data we found a significant increase of room temperature in every region of the state of Paraiba, which was shown by the difference between the averages of the period of the normal 30 years (1961-1990) and the averages of the last four years (2011 - 2015), table 1. The highest temperature rise was observed in the weather station of the city of Monteiro, Paraíba Cariri and the smallest increase was observed in the coastal region. Table 1. Climate variables, ambient temperature and relative humidity, the Paraíba state in the period of normal (1961-1990) and the last four years (2011-2015). Municípalities of Paraíba Temperature (°C) 196120111990 2015 Campina Grande João Pessoa Monteiro São Gonçalo 22,40 26,10 23,69 26,50 24,34 27,66 26,00 28,65 ∆T (°C) 1,94 1,56 2,31 2,15 UR (%) 1961-1990 20112015 74,70 80,80 62,70 59,80 76,57 74,5 60,74 63,28 ∆UR (%) 1,84 - 6,3 - 1,96 3,48 These results agree to preliminary data released by the IPCC (Intergovernmental Panel on Climate Change) in September 2013. According to the IPCC the Brazilian climate could suffer the effects of global warming by the end of this century. The South and Southeast regions may have increased to 0.5% in average temperature by the end of the century and the Midwest, Northeast and North may have average temperatures increased by 1.5%. As for IPCC these optimistic projections, that is, controlling the emission of greenhouse gases. In contrast scenario, the temperature may rise more than the double compared to these projections. As a consequence of such heating would be: melting glaciers, the elevation of the oceans due to the melting and thermal expansion of the water, increasing the amount of clouds, water vapor, and consequently, the amount of rainfall, change in environment characteristics in different regions of the planet (Xavier & Kerr, 2004). The relative humidity showed greater mean decrease on the coast (João Pessoa) and higher in the high backcountry (São Gonçalo). The effects of moisture on the climate are felt both in temperature and in rainfall. Water, because of its specific heat, tends to keep longer temperatures, so that there is a smaller variation of them, namely the amplitude is smaller the higher the humidity. In addition, in more humid regions or who are most affected by humidity, rainfall tends to be higher, because the saturation of the air causes condensation is more frequent. High ambient temperatures associated with high relative humidity are the main factors that interfere negatively on productivity. Since these variables together difficult when the heat loss by evaporative forms, breath and perspiration. What depending on the species may become a limiting factor of animal exploitation for economic purposes in certain regions. Table 2 shows the mean and the differences between the averages of precipitation and temperature and humidity index (THI) in the state of Paraíba. Regarding rainfall there was a reduction in the amount of rainfall for three regions in recent years compared to the normal of the period (1961-1990), represented by the municipalities of João Pessoa, Monteiro and São Gonçalo, coastal, cariri and the high wilderness regions, respectively. Regarding the THI it was observed that there was an increase above 2 points for all regions, with the highest average observed in São Gonçalo 3.52 from above hinterland region. These results demonstrate that the condition of thermal comfort for the livestock in all of Paraíba state regions is becoming more difficult to achieve. For Azevedo et al. (2005) THI is an excellent indicator of thermal comfort, since this index takes into account the relationship between the ambient temperature and relative humidity. _______________________________________________________________________________________________________________________________ Página - 2 - de 3 52a Reunião Anual da Sociedade Brasileira de Zootecnia Zootecnia: Otimizando Recursos e Potencialidades Belo Horizonte – MG, 19 a 23 de Julho de 2015 Table 2. Means of rainfall and temperature humidity index the difference between these variables in relation to the normal period (1961-1990) and the last four years (2011-2015) in the state of Paraíba. Municípalities of Paraíba Campina Grande João Pessoa Monteiro São Gonçalo Precipitation (mm) 61-90 11-15 875,4 893,47 2145,4 1941,35 712,5 555,6 995,5 860,97 THI ∆P 18,7 -204,05 -157 -134 61-90 70,58 75,18 71,95 74,32 ∆THI 11-15 73,00 77,94 74,21 77,84 2,42 2,76 2,26 3,52 According to Rosenberg et al. (1983) an THI between 75 and 78 is an alert condition to producers, indicating that action must be taken to avoid losses, which was observed in this study for the municipalities of João Pessoa, 77.94 and São Gonçalo, 77, 84, litoral and high wilderness regions, respectively. Yet according to the authors measures of a THI 79-83 means danger, especially for feedlot cattle and THI equal to or greater than 84 is an emergency situation, emergency measures must be taken to avoid loss of animals. Conclusions All Paraíba state regions are suffering from climate change due to the greenhouse effect. The average elevation of THI in recent years indicates that changes in attitude should be intensified to allow the survival and productivity of farm animals do not become increasingly expensive in the state. Acknowledgements The INMET for providing data from meteorological database for teaching and research of weather stations located throughout the state of Paraíba. Literature Cited AZEVEDO, M.; PIRES, M.F.A.; SATURNINO, H.M. et al. 2005. Estimativa de níveis críticos superiores do índice de temperatura e umidade para vacas leiteiras 1/2, 3/4 e 7/8 Holandês-Zebu em lactação. Revista.Brasileira de Zootecnia34: 2000-2008. ROSENBERG, N.J; BLAD, B.L; VERMA, S.B. 1983. Microclimate: the biological environment. 2ed. New York: Wiley-interscience Publication. LUCENA, A.F.O. 2010. Proposta metodológica para avaliação da vulnerabilidade às mudanças climáticas globais no setor hidroelétrico. Tese Doutorado. Universidade Federal do Rio de Janeiro, Rio de Janeiro. MEEHL, G.A., T.F. STOCKER, W.D. COLLINS, P. FRIEDLINGSTEIN, A.T. GAYE, J.M. GREGORY, A. KITOH, R. KNUTTI, J.M. MURPHY, A. NODA, S.C.B. RAPER, I.G. WATTERSON, A.J. WEAVER, Z.-C. ZHAO, 2007, “Global Climate Projections”. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. THOM, E.C. 1959. The discomfort index. Weatherwise, Boston, 12:57-60. XAVIER, M.E.R.; KERR, A.S. 2004. A análise do efeito estufa em textos paradidáticos e periódicos jornalísticos. Cad. Bras. Ens. Fís., 21:325-349. _______________________________________________________________________________________________________________________________ Página - 3 - de 3