Greenhouse Gas Emissions: Historical and Projected Methane Emissions from Rice Cultivation in Malaysia (1990-2030)

Abstract

Global warming and climate change has reached the alarming levels due to increase of greenhouse gas emissions into the atmosphere which includes carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O). Flooded rice (Oryza sativa L.) cultivation has been identified as one of the prominent global agricultural sources of anthropogenic CH₄ emissions. Moreover, it has been estimated that global rice production is responsible for 11% of total anthropogenic CH₄ emissions. The inventory of CH₄ emission from rice cultivation in Malaysia was estimated from 1990 to 2014 and was also used as basis for computing the projected emissions up to 2030 by using Auto-Regressive Integrated Moving Average (ARIMA) model. Results showed that CH₄ emissions is higher from granary area (continuously flooded) than non-granary area (rain-fed) due to different water management practices. Continuously flooded irrigation system which lead to anaerobic conditions emit almost (75%) higher CH₄ than rain-fed irrigation system. Emissions forecasted will be continuously increase from 2015 to 2030 within the confidence limits. Emissions were forecasted to increase up to 88 Gg by 2030 due to increase of country population which will lead to expansion of cultivation area in order to fulfil country needs.