تخریب محیط زیست، رشد اقتصادی و مصرف انرژی: شواهد منحنی کوزنتس زیست محیطی در مالزی

This paper tests for the short and long-run relationship between economic growth, carbon dioxide (CO2) emissions and energy consumption, using the Environmental Kuznets Curve (EKC) by employing both the aggregated and disaggregated energy consumption data in Malaysia for the period 1980–2009. The Autoregressive Distributed Lag (ARDL) methodology and Johansen–Juselius maximum likelihood approach were used to test the cointegration relationship; and the Granger causality test, based on the vector error correction model (VECM), to test for causality. The study does not support an inverted U-shaped relationship (EKC) when aggregated energy consumption data was used. When data was disaggregated based on different energy sources such as oil, coal, gas and electricity, the study does show evidences of the EKC hypothesis. The long-run Granger causality test shows that there is bi-directional causality between economic growth and CO2 emissions, with coal, gas, electricity and oil consumption. This suggests that decreasing energy consumption such as coal, gas, electricity and oil appears to be an effective way to control CO2 emissions but simultaneously will hinder economic growth. Thus suitable policies related to the efficient consumption of energy resources and consumption of renewable sources are required.

Nowadays, Greenhouse gases (GHG) and resulted global warming and climate change are well debated among scientists, researchers, head of states, government and policy makers. Carbon dioxide (CO2) emissions as the most important anthropogenic GHGs, which are responsible for more than 60% of the greenhouse effect (Ozturk and Acaravci, 2010), significantly contribute to the increase in global temperatures and climate change (IPCC, 1996). The main part of the increase in CO2 emissions can be attributed to energy consumption especially, fossil fuels burning such as oil, gas and coal. While conserving energy consumption may be the most direct way of managing the emissions problem, this reduction at the expense of economic growth may not be a desirable outcome (Lotfalipour et al., 2010). This is because of the significant relationship between economic growth, energy consumption and CO2 emissions. Malaysia, a high income developing country in South East Asia, experienced remarkable economic growth over the past three decades. Likewise other developing countries, energy played a significant role in boosting economic growth. Energy consumption in Malaysia increased by average annual growth rate of 6.76% in 2010 to settle at 72646 kilo tone of oil equivalent (ktoe) from 6093 ktoe in 1971 (world Bank, world development indicator). The Four-Fuel Diversification policy in 1981 and the Five-Fuel Diversification policy in 2002 were introduced by Malaysian government to decrease the dependency of the country to oil as a main energy sources. As a result, the share of oil and petroleum products in primary energy supply declined from 75.55% in 1980 to 32% in 2010. Natural gas has become the main supplier of energy consumption (47.17%) followed by oil (32%), coal (18.87%) and hydropower (2.14%) in 2010. Despite of the implementation of various energy related policies, Malaysia is still dependent on fossil fuels sources such as natural gas, coal and oil (Oh et al., 2010). With the growing energy demand in sustaining the country's economic growth in the future, it is inevitable that CO2 emission will continue to increase, with fossil fuels as the main contributor in the energy supply and demand. So far, the existing literatures utilized aggregate energy data to investigate the relationship between economic growth, energy consumption and CO2 emissions. Since different sources of energy may have different impacts on economic growth and CO2 emissions, the relationship between CO2 emissions, disaggregate energy consumption and economic growth undoubtedly has significant implication for economic and environmental policies. The aim of this study is to investigate the long-run and causal relationship between CO2 emissions, economic growth and disaggregate energy consumption (oil, coal, electricity, and gas consumption) in Malaysia in order to minimize the aggregation bias problem. This may help policy makers in implementation of suitable policies to identify the effects of different type of energy sources on economic growth and CO2 emissions. The rest of the paper is structured as follows: Section 2 briefly describes energy context in Malaysia, Section 3 explains the previous studies, the proposed model and data are discussed in Section 4, methodology in Section 5, empirical results are presented in Section 6, discussion and policy implications are reported in Section 7 and the last section states the conclusions.

The cointegration relationship between environmental degradation, economic growth and energy consumption as a way of analyzing the validity of environmental Kuznets curve (EKC) hypothesis is gaining popularity in economics. The Malaysian experience focusing on the role of energy consumption, using both aggregated and disaggregated energy data, and its relationship with carbon dioxide (CO2) emissions in shaping the EKC for the period 1980–2008 was considered. Cointegration analysis was conducted using the ARDL bounds testing approach developed by Pesaran et al. (2001) and Johansen and Juselius (1990) cointegration approaches. The result of cointegration test revealed a long-run relationship between (1) carbon emissions, economic growth and energy consumption; (2) carbon emissions, economic growth and oil consumption; (3) carbon emissions, economic growth and gas consumption; (4) carbon emissions, economic growth and coal consumption and (5) carbon emissions, economic growth and electricity consumption. Later the long and short-run coefficients in the cointegrated models were estimated. The results showed that the EKC is not supported using the aggregated data (energy consumption). However using disaggregated energy data (oil, coal, gas and electricity) there is evidence of EKC. The empirical results suggest that electricity, gas and coal consumption are found to have positive effects on CO2 emissions in long-run. Coal consumption also contributes to emissions in short-run. Oil has a negative impact on CO2 emissions in long-run. This may be justified by the reduction in the use of oil while relying more on gas, coal and non-fossil fuel (Nurdianto and Resosudarmo, 2011). Furthermore Malaysia has tried to reduce its dependency on oil consumption in electricity generation. The oil share in electricity generation has declined from 32.3% in 1992 to 8.77% in 2002 and 0.57% in 2010 (Malaysia Energy Information Hub, MEIH). The short-run results show that EKC hypothesis does not hold for Malaysia in all the cases. The evidence of the EKC in the long-run and not in the short-run suggests that CO2 emissions are going to decline over time in Malaysia. For the coefficients of ECTt−1ECTt−1in all of the disaggregated models the signs were as expected and statistically significant. The results of the CUSUM and CUSUMSQ tests indicated that all coefficients in the short and long-run models were stable. The result of long-run Granger causality shows that there are bi-directional causal relationships between economic growth and energy consumption, CO2 emissions and economic growth, energy consumption and CO2 emissions, coal consumption and economic growth, CO2 emissions and coal consumption, gas consumption and economic growth, CO2 emissions and gas consumption, electricity consumption and economic growth, CO2 emissions and electricity consumption, oil consumption and economic growth and CO2 emissions and oil consumption. This implies that any conservation policies related to coal, gas, electricity and oil consumption can decline CO2 emissions however concurrently, will hinder economic growth. In the short-run there is only one uni-directional causality from gas consumption to economic growth. This implies that decreasing energy consumption especially coal, oil and electricity seems to be an effective way to control carbon emissions without holding back the economic growth in the short-run.