Sugarcane production and climate trends in Paraíba state (Brazil).

Statistical surveys to detect trends in time series are fundamental tools to evaluate farming dynamics of sugarcane and of adaptation plans for possible impacts caused by climate change. This work analyzed the influence of climate change in the cultivation of sugarcane in the state of Paraíba (Northeast Brazil), in order to investigate what are the consequences of temperature increase, air humidity level, and changes in the precipitation regime forecasted for the region in sugarcane farming. Data of temperature, total precipitation, and relative humidity of six meteorological stations kept by the Brazilian National Institute of Meteorology (INMET) spread across the state of Paraíba and data from the area of sugarcane harvesting from the Brazilian Institute of Geography and Statistics (IBGE). Mann-Kendall trend test was employed in order to analyze the existence of trends in each station, separately. The results pointed trends of significant increase in temperature for the stations of Campina Grande, João Pessoa, Monteiro, Patos, and Sousa. The stations of Areia, Campina Grande, and João Pessoa obtained significant precipitation trends. Regarding relative humidity, the stations of João Pessoa, Monteiro, and Patos presented significant decreasing trends, while Sousa showed significant increase trends. The results suggest that these trends may be increasing sugarcane production close to the coast of the region and decreasing production inland.

Comparison between observed and estimated data to assess air temperature variability and trends in the Sertão Paraibano mesoregion (Brazil).

Given the importance of climate for society at different scales, such as local, regional, and global scales, the analysis of trends of climatic elements improves the assessment of projections and variations, aiding in the design of policies focused on processes of adaptation to and mitigation of the effects of climate change. The aim of this study was to detect mean air temperature trends in the Sertão Paraibano mesoregion in Brazil by constructing temperature series with observed data provided by the Brazilian National Institute of Meteorology (INMET) collected in the localities of Patos and São Gonçalo and with data estimated using Estima_T software to study the spatial and temporal distribution of the mean air temperature of seven localities in the Sertão Paraibano mesoregion: Água Branca, Aguiar, Coremas, Patos, Princesa Isabel, São Gonçalo, and Teixeira. The temperature series with observed and estimated data were compared, showing the variability of using temperature estimates to overcome the lack of meteorological stations in the study area. Descriptive analysis shows low data dispersion in relation to the annual mean values and, therefore, low variability. The monthly mean temperature pattern was similar in all localities and December was always the warmest month, whereas July was the coldest, both in the estimated and observed data series. The non-parametric Mann-Kendall test indicated that estimated series show trends of significant increases in mean air temperature, in annual, biannual, quarterly, and monthly periods, in all localities. Sen's slope results indicate significant increases in temperature from 0.008 to 0.011 °C/year.