Land use change and greenhouse gas emissions: an explanation about the main emission drivers

Abstract

Global warming is attributed to the increase in greenhouse gas (GHG) emissions, such as carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O). Land use changes significantly impact on GHG emissions, accounting for approximately 44% of the country’s emissions in 2019. This review addresses the main pathways of GHG formation in the soil, focusing on the influence of land use changes on GHG emissions. It is found that soil CO₂ emissions are related to root respiration, microorganisms, and organic matter (OM) decomposition in the soil. Changes in land use can alter soil characteristics, favoring increased CO₂ emissions. Soil CH₄ emissions occur under anaerobic conditions by methanogenic microorganisms; however, land use changes, such as forest conversion to pasture, can increase CH₄ emissions due to a higher concentration of methanogenic microorganisms in the soil. On the other hand, N₂O is produced in the soil during nitrification and denitrification processes by microorganisms, and nitrogen fertilization in agricultural areas can increase N₂O emissions, especially when associated with soil moisture and the availability of organic carbon. It is important to understand the dynamics of GHG formation and emissions resulting from land use changes because efficient management strategies can reduce these emissions and contribute to Brazil’s goals for GHG reduction as established in international agreements.

Keywords:
Carbon stock; methane in the soil; nitrous oxide in the soil