Consequência do aumento da temperatura média global em 1,5ºC e 2ºC no balanço hídrico para o eucalipto na América do Sul

Abstract

The 21st Conference of the Parties, held in the city of Paris in 2015, established a new international agreement, known as the Paris Agreement, with the main objective of keeping global warming below 2°C and making efforts to limit this increase to 1.5°C, in relation to pre-industrial levels. However, even if the thresholds foreseen in the Paris Agreement are reached, several impacts on the climate system are still inevitable, mainly on a local scale, which may generate new vulnerabilities and expand those that already exist. In this sense, the objectives of this master's dissertation were: to analyze the regional climatological patterns of the near surface air temperature and precipitation over South America (SA) due to the increase in the global average temperature by 1.5ºC and 2ºC when compared to the pre-industrial period; to analyze the impacts on the extracts of the climatological water balance (Real Evapotranspiration, Water Deficiency and Water Surplus), and the consequences on the aptitude for eucalyptus cultivation in SA. As key results, it is noteworthy that the regional warming threshold of 1.5°C and 2°C will be reached primarily at the South American continent central area. Regarding the patterns of precipitation, it should be noted that the Brazil’s Southern region, the northern coast of the Brazilian Northeastern region, northern Argentina, Uruguay and parts of Peru, Ecuador, Colombia and Venezuela will be affected with an increase in average annual precipitation, up to 100 mm year-1, in the period when the global average warming thresholds are projected at 1.5°C and 2°C. This result will disfavor the cultivation of eucalyptus in 49.2% and 56.8% of the South American continent, during the heating period of 1.5°C and 2°C, respectively. In Brazil, only the Southern and part of the Southeastern regions will be suitable for growing eucalyptus considering the water availability. For the other regions, mainly in the Midwest and North of Brazil and the central north of Argentina, the cultivation of eucalyptus will be negatively affected, requiring mitigation measures and adaptation strategies, such as the use of species (hybrids and genetically altered) and the use of irrigation, which would represent a great addition to the costs of operation and of forest management.