Carbon dioxide emissions : Who is responsible and who is actually doing research ?

© 2019 by the authors; licensee Growing Science, Canada.


Introduction
Most climate researchers believe that the current global warming trend is the results of human expansion called "greenhouse effect" 1 where the atmosphere traps heat radiating from Earth toward space.During the past century, humans have increased atmospheric CO2 concentration by at least a third, which is considered as the most important long-lived "forcing" of climate change.Scientists all over the world are responsible to do their best on offering practical solutions to reduce the effect of CO2 on environment 1 .Human activities are believed to be the main reason for changing the natural greenhouse.For years, the burning of fossil fuels such as coal and oil has been blamed for the concentration of CO2.This occurs since the coal or oil burning process develops chemical reaction of carbon with oxygen in the air to generate CO2.In other worlds, many agricultural, industry, and other human activities have increased the level of greenhouse gases.The primary consequence of green gas effect will increase temperature in most part of the world and we may expect some lands sink into the oceans.Other regions face with more natural disasters such as flood, starvation, etc.If this trends continuous, life conditions will become difficult and many people will face shortage of natural food.Therefore, it is necessary to do more studies on learning more about the green gas effects and learn how to handle the tough circumstances that next generations may face.This paper investigates how seriously scientists from major countries performed studies on carbon dioxide emissions during the past 80 years.The study uses a well-known method to measure the relative efficiency of the countries.

The proposed study
The propose study of this paper uses data envelopment analysis 2 (DEA) to measure the relative efficiency of similar possibly non-financial units.The study considers different inputs and outputs and by assigning some weights for these inputs/outputs measures the relative efficiency of different units.DEA has been widely used for studies in green gas effects [3][4][5][6][7][8][9][10][11][12] .Fig. 1 shows the structure of the proposed study of this paper.

Fig. 1. The structure of the proposed method
As we can observe from the results of Fig. 1, Fossil CO2 emissions in million ton per year is considered as the input.In other words, the more CO2 emissions generated by each country, the stronger commitment for doing research on carbon dioxide emission.The proposed method also considers three outputs as scientometrics data; namely total publications, h-index and I-10 for measuring the effects of the studies published by each country.The output "Total publications" covers all papers published indexed in Scopus database over the period 1959-2019 with the keyword "carbon dioxide emission" in the title, keyword or abstract.Our survey has determined 10034 records of data.Next, we filtered the data based on each country and determined h-index and I-10 statistics.In our survey, the number of publications with at least 10 citations represents I-10 index while h-index is defined as the maximum value of h such that the given author(s) has published h-articles that have been cited at least h times 13 .

Table 1
The summary of the input/output data  1, China has published 1407 articles which are associated with carbon dioxide emissions.The country has published at least 62 articles received 62 times of citations and maintains 376 articles where each articles has received at least 10 citations.The country produced 10,877.22 million ton CO2 in 2017.These 26 countries have produced about 80% of the fossil emissions per year 2017.Thus, it is important to learn who serious they are in doing research for reducing the effect of green gas effect.The implementation of DEA has provided the relative efficiency of 26 countries and Fig. 2 presents the results of our survey.

Discussion
According to the results of Fig. 2, United Kingdom has been considered efficient compared with other countries in terms of generating higher good quality papers generating only about one percent of total carbon dioxide emissions.It appears that UK based researchers have been more serious about global warming.On contrast, China which is responsible for about 30% of global carbon dioxide emissions has performed poorly in terms of contributing high quality achievements for scientific society (efficiency = 0.05365).The other observations is that some developing countries such as Malaysia and Taiwan with relative efficiency of about 0.60 have maintained good contribution to scientific community despite the fact that they were not blamed by generating significant amount of CO2 emissions.United States produced about 5107 million ton CO2 in 2017 which is almost half of the pollution generated by China but maintained an efficiency of about 16%.Although the number seems to be better than China but it is significantly lower than many other European countries such as France with relative efficiency of 0.54 and Italy with relative efficiency of 0.51.The results have indicated that countries like China and United States with big economy are not as serious as many other developing or developed countries for supporting scientific studies on carbon dioxide emissions.Global warming is a long-term rise in the average temperature of the Earth's climate system, a climate change perspective given by temperature measurements and by multiple impacts of the warming.

Conclusion
This paper has presented an implementation of data envelopment analysis to measure the relative efficiency of 26 countries representing of at least 80% of carbon dioxide emissions in the world using 0.00E+00 Kingdom produced only about one percent of carbon dioxide emissions, the country has been nominated efficient compared with other 25 countries for contributing high quality articles.As public reactions to global warming and concern about its effects tend to increase, we need more awareness among researchers for placing more efforts on carbon dioxide emissions.

Table 1
demonstrates the summary of the data used for the proposed study of this paper.According to Table *https://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions known method called data envelopment analysis.The study has tried to measure the effects of good quality articles in this area using two scientometrics figures; namely h-index and I-10.The study has revealed that while many developing countries such as Malaysia and Turkey have successfully contributed scientific achievements on carbon dioxide emissions, many developed countries such as China and United States have performed poorly.It appears that European countries have been more serious about global warming since many of them have contributed high quality articles.While United