چکیده:
شناخت عوامل مؤثر بر کیفیت محیطزیست که با استفاده از شاخص میزان انتشار گاز دیاکسید کربن بهعنوان یکی از اصلیترین شاخصهای نشان دهنده گرم شدن کره زمین قلمداد میشود، موضوع بررسی این تحقیق است. عواملی مانند مصرف انرژی، صادرات، تراکم جمعیت و تولید سرانه بیشترین سهم را در تولید و انتشار گاز دیاکسید کربن دارند. مسئله این پژوهش به دست آوردن رابطهای تجربهای بین عوامل یادشده و انتشار دیاکسید کربن در کشورهای مورد مطالعه است. روش پاسخگویی به مسئله مزبور از طریق تحلیل اقتصادسنجی دادههای پانلی برای کشورهای خاورمیانه در سالهای 1990 تا 2015 است. دادهها نیز از سایت بانک جهانی دریافت شده است. لازم به ذکر است که دادههای مورد نیاز پژوهش از پایگاه دادهای بانک جهانی استخراج شده است. درواقع با توجه به متغیرهای احتمالی مؤثر بر میزان انتشار دیاکسید کربن که در مبانی نظری بیان شده است، این تحقیق، تأثیر آن متغیرها را برای کشورهای خاورمیانه آزمون کرده و معنیداری و یا عدم معنیداری آنها را برای کشورهای حوزه خاورمیانه نشان داده است. نتایج تحقیق نشان میدهد که تأثیر عوامل تولید سرانه، تراکم جمعیت و میزان مصرف انرژی سرانه بر انتشار دیاکسید کربن سرانه معنیدار است، درحالیکه تأثیر صادرات سرانه کشورها بر انتشار دیاکسید کربن سرانه معنیداری نیست، همچنین نتایج این مطالعه، فرضیه محیطزیستی کوزنتس مبنی بر وجود رابطه U شکل معکوس بین رشد اقتصادی و میزان انتشار گاز دیاکسید کربن را برای کشورهای مورد نظر تأیید میکند.
1 Introduction
Studies show that in recent years, climate change around the world has been increasing rapidly and has brought about irreparable economic, social and development consequences. Due to the prevailing conditions in different regions, the effects of climate change will vary, and due to the severity and weakness of these symptoms and their effects, significant damages will be caused annually by the increase in temperature. The earth will increase (Alishiri, Khanly. & Bagheri, 2015). Promoting sustainable patterns of energy production and consumption is therefore essential, and the international community is in dire need of a more sustainable lifestyle to reduce energy consumption. Based on predictions, CO2 emissions from energy consumption in developing countries will surpass developed countries in the coming years (Alishiri et al., 2015).
The purpose of this study is to identify factors affecting carbon dioxide emission, as one of the key environmental considerations, in the Middle-eastern countries. In this study, first, the definition and concept of environmental quality, the study area and factors affecting environmental quality have been addressed. Then, the research and modeling method is explained and finally the results of modeling and policy suggestions that can lead to an increase in the quality of the environment are presented.
2 Materials and Methods
Due to the high share of carbon dioxide in contaminating countries and its distinct data, carbon dioxide emission have always been considered as indicators and environmental quality in research. The same criterion was used in this study. The study area in this research is Middle-eastern countries. The method used in this study is Panel data and the data is annual. The data ranges from 1990 to 2015. In order to overcome the sample size problem, panel data from the Middle-eastern countries have been used to test the causal relationship between energy consumption growth, economic growth, export growth, population growth and carbon dioxide emission growth.
3 Results and Discussions
The purpose of this study was to identify the relationship between carbon dioxide emission and variables such as GDP, GDP2, energy consumption, population density and exports for the Middle East countries during the years 1990 to 2015. In addition, the existence of a Kuznets curve (EKC) for these countries was studied. To analyze the relationships, the panel test data reliability tests, the determination of the panel model test, and finally, the significance analysis of the coefficients were used. The results showed that the relationship between energy consumption variables, GDP, GDP2 and population density with carbon dioxide emission is significant. Also, there is a U-inverse relationship between GDP2 and carbon dioxide emission, so the Kuznets hypothesis applies to these countries. In contrast, the relationship between exports and carbon dioxide emission in this study is not significant. This means that, at the outset, the growth of countries' production is accompanied by the addition of carbon dioxide gas, but after the initial stages of development by a country production increases with the reduction of carbon dioxide gas. The relationship between exports and carbon dioxide emission in this study for the Middle East countries was not confirmed.
4 Conclusion
The purpose of this study was to identify factors affecting environmental quality. According to the methodology, GDP2, GDP, energy consumption and population density are the main factors affecting CO2 emissions and environmental quality in Middle Eastern countries.
A number of policy implications can be made based on the findings of this study. 1) Population policy should move towards decentralization of cities, especially metropolises, in addition to population control. This has led to the spread of population throughout the country, which has reduced the use of contaminants that will reduce pollution. 2) Due to the significant relationship between energy consumption and CO2 emissions, policy should be taken to replace renewable energy with fossil fuels. Failure to reduce energy consumption in the Middle East countries should include funding for scientific and research institutions through projects to increase energy efficiency and reduce the use of fossil fuels. 3) Middle East countries should consider increasing GDP by enhancing the production of goods and services and increasing the productivity of production entities, as in the Kuznets hypothesis (EKC) there is a reverse U-shaped relationship between economic growth and pollution. Increased production and economic growth will reduce carbon dioxide emissions and air pollution. 4) Given that the relationship between export and CO2 emission for the Middle East countries is not statistically significant, production can be further increased by increasing exports, which can lead to economic growth. It is recommended that the Kuznets hypothesis reduce pollution. 5) Middle East countries should use environmentally friendly technologies in the production of goods and services to directly increase pollution production and reduce pollution according to the Kuznets hypothesis as well as directly prevent the spread of pollution. 6) Taxation should be on the agenda of governments to reduce carbon dioxide production technologies as well as domestic pollution generating plants to reduce CO2 emissions.
خلاصه ماشینی:
نتایج تحقیق نشان می دهد که تأثیر عوامل تولید سرانه ، تراکم جمعیـت و میـزان مصـرف انـرژی سرانه بر انتشار دی اکسید کربن سرانه معنی دار است ، درحالی که تأثیر صـادرات سـرانه کشـورها بـر انتشـار دی اکسید کربن سرانه معنی داری نیست ، همچنین نتایج این مطالعه ، فرضیه محیط زیستی کـوزنتس مبنـی بـر وجود رابطه U شکل معکوس بین رشد اقتصادی و میزان انتشار گاز دی اکسـید کـربن را بـرای کشـورهای مورد نظر تأیید می کند.
در مطالعات خـارجی مـی تـوان بـه مطالعـات (٢٠١٣ ,Ozcan)، (٢٠١٤ ,Nicholas) و (Bella & ٢٠١٣ ,Massidda) 1 Organization for Economic Co-operation and Development 2 OECD Environment Directorate 3 Environmental Performance Index اشاره نمود که به بررسی وجود منحنی کوزنتس و رابطه انتشار دی اکسید کربن و رشد اقتصادی پرداخته اند.
همچنـین (٢٠١٥ ,Wang et al) در مطالعه خود به این مسئله پرداخته اند که چه عواملی بر انتشار دی اکسید کـربن موثرنـد و بـا استفاده از روش مدل های پانل به این نتیجه رسیده است که یک رابطه مستقیم بین دی اکسید کربن و مصرف انرژی و همچنین بین رشد اقتصادی و دی اکسید کربن وجود دارد.
نیکـو اقبال و همکاران (١٣٨٩) به این مسئله پرداخته اند که آیا رابطه علی پویا بین متغیرهـای رشـد مصـرف انـرژی ، رشـد اقتصادی و رشد انتشار دی اکسید کربن وجود دارد؟ و با استفاده از روش داده های تلفیق پویا و تکنیـک GMM-SYS در بلندمدت و برای سه گروه درآمدی متفاوت به این نتیجه رسیده اند که در همـه گـروه هـای درآمـدی رابطـه علـی یکطرفه از رشد اقتصادی به مصرف انرژی وجود دارد، در گروه ML ایـن رابطـه بـه صـورت مثبـت برقـرار اسـت .