PROJECTED GREENHOUSE GAS (GHG) EMISSIONS FROM AGRICULTURE IN PIAUI, BRAZIL

Abstract

This study aims to predict the evolution of average greenhouse gas (GHG) emissions in the state of Piauí, based on the 242 municipalities of the state, as well as: 1 - estimate the descriptive statistics associated with GHG emissions and average annual rainfall observed in the state of Piauí in the period from 1973 to 2023; 2 - create a model that is capable of predicting the trajectory of average greenhouse gas emissions that are aggregated from the emissions observed in the municipalities annually between 1973 and 2023; 3 - hierarchize, in ascending order of GHG emissions, the municipalities of Piauí and divide them into quintiles, to evaluate the average behavior of emissions and rainfall in each quintile. The study's guiding hypothesis is that the 33 municipalities located in the southern part of the state, which are located within the agricultural frontier of MATOPIBA, where agriculture is intensive in the use of machinery, chemical fertilizers, pesticides, and cattle raising, are the largest GHG emitters in the region. The ARIMA (0, 2, 1) model was used to make the predictions. The main evidence from the study showed that there was a significant increase in GHG emissions in the state of Piauí during the analyzed period and that, in accordance with the study's guiding assumption, the municipalities located in the MATOPIBA region had the highest average GHG emissions during the analyzed period.