The greenhouse effect plays a crucial role in the continued survival of life on Earth. However, human activities such as agriculture, industrialization, and urbanization have damaged the natural environment and increased environmental degradation (henceforth ED) (Selcuk, Gormus, & Guven, 2021). Thus, ED, pollution, global warming, and climate change have received considerable attention from academics, researchers, policymakers, and energy economists over the past several decades (Ali, Ashraf, Bashir, & Cui, 2017; Allard, Takman, Uddin, & Ahmed, 2018; Chien et al., 2021). In order to reduce poverty and speed up economic growth, developing nations need to boost production and other economic activities that raise living standards. Promoting these activities causes an increase in greenhouse gas emissions that have severe consequences for the global climate (Akram, 2013). Economic growth in developing countries is more carbon intensive than economic growth in developed countries because of technological development and innovation.
According to Kuznets' seminal 1955 work, there is an inverted U-shaped relationship between income and income inequality. This relationship has been reinterpreted as an Environmental Kuznets Curve (EKC) since 1990 (Ullah & Khan, 2020). Since then, the EKC hypothesis has been the predominant explanation for the relationship between economic growth and ED. According to the EKC hypothesis, economic growth and ED are inversely related (Demissew Beyene & Kotosz, 2020). It hypothesizes that, high resource consumption during the initial stages of economic development inevitably reduces bio capacity and increases the ecological footprint, resulting in a rapid increase in pollution levels. Upon reaching a certain income level, however, the trend reverses, resulting in an improvement in the environment.
Several empirical studies investigating the validity of EKC using samples from different countries observed an inverted U-shaped EKC curve (Dogan, Taspinar, & Gokmenoglu, 2019; Panayotou, 1997; Sarkodie & Ozturk, 2020; Sarkodie & Strezov, 2019). Moreover, other studies have provided a U-shaped EKC (Ozcan, 2013; Ozturk & Al-Mulali, 2015). Although agriculture is recognized as a driver of economic growth, particularly in emerging countries, some scholars are concerned about its potential impact on environmental quality (Gollin, Parente, & Rogerson, 2002; Lewis, 1954). Increased agricultural production has a significant effect on air pollution as it increases greenhouse gases such as methane and nitrous oxide (Cetin, Bakirtas, & Yildiz, 2022). Various empirical studies have examined the possibility of an environmental Kuznets curve in the agriculture industry (Ali et al., 2017; Cetin et al., 2022; Ntim-Amo et al., 2021; Ogundari, Ademuwagun, & Ajao, 2017; Ullah & Khan, 2020).
Extreme temperatures, irregular rainfall, flooding, and increased in disease incidence will all affect global production and reduce farmers' productivity (Ogundari et al., 2017). Future changes in temperature, carbon dioxide levels, and precipitation due to global warming are expected to have an effect on rice production. Rapid climate change repercussions include the adverse effects of extreme weather on rice production systems and food availability (Chandio, Magsi, & Ozturk, 2020; Muoneke, Okere, & Nwaeze, 2022).
Rice, a staple food for the majority of the world's population, is consumed by approximately 3 billion people every day (Krishnan, Ivanov, Masulis, & Singh, 2011). Wetland rice farming is one of the largest contributors to atmospheric methane (CH4) and approximately 90% of the world's rice is grown in flooded fields, where the anaerobic conditions are ideal for the formation of methane (Bouwman, 1991; Matthews, Fung, & Lerner, 1991). Bouwman (1991) estimated that rice production could increase by 65% between 1990 and 2025, leading to an increase in annual methane emissions from 92 Tg CH4 to 131 Tg in 2025. A staple food for over half of the world's population, rice is the agricultural product with the third highest global production, after maize and sugar cane.
The variety of empirical studies examining the EKC hypothesis's reliability is evident from the current review of the empirical literature. ED must be measured with agriculture included, however, in countries that rely heavily on agriculture. Therefore, this study validates the EKC using data from the top ten rice-producing countries in the world. Asia is the largest producer and consumer of rice, with China, India, Thailand, and Indonesia among the largest producers and consumers (Irshad, Xin, & Arshad, 2018; Matthews et al., 1991).
Our research contributes in numerous ways to the existing body of literature. First, we examine the aggregated validity of the inverted U-shaped EKC and then the disaggregated reliability. Second, we test the validity of the EKC in the top 10 rice-producing countries from 1995 to 2018, which has not been examined in a study using this sample to the best of our knowledge. Thirdly, no other study has used PM 2.5 emissions, PM 10 emissions, and CH4 emissions emitted from the rice cultivation process as proxies for ED separately at aggregated (i.e., overall economy) and disaggregated (i.e., agriculture sector) levels (Bouwman, 1991; Matthews et al., 1991). Fourthly, we used two distinct models (i.e., aggregated and disaggregated) for each environmental indicator (i.e, PM 2.5, PM10, and CH5).
The rest of this article is arranged as follows: The framework of the environmental Kuznets curve is described in Section 2. The third section describes the data, while the fourth section discusses the empirical framework. Section 5 presents the findings and discussion of growth in general. The sixth section discusses the empirical results, and the last section concludes the paper with policy implications.