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 effects of CO₂ on environment. This paper uses data envelopment analysis to measure the effects of researches accomplished by scientists from 30 countries which are representative of producing over 80% of CO₂ in the world. The study uses 10034 articles published in Scopus database from 1959 to March, 2019. The study uses the amount of CO₂ produced by each country as the input and total publications, h-index and I-10 as the output of the DEA model. The results indicate that despite the fact that China was responsible for producing nearly 30% of the CO₂, the scientists of this country contributed the least on carbon dioxide emissions. In addition, United Kingdom was responsible for about one percent of CO₂ emissions but the researchers of UK performed the best in terms of offering good quality studies.

Construction operations are blamed as one of important causes of green gas effects. During the past few decades, there has been tremendous efforts to reduce the negative effects of construction operations on environment. This paper presents an application of data envelopment analysis to measure the relative efficiencies of the researches accomplished by various countries around the world on green construction or green management. The study expects countries that produce higher amount of CO2 accomplish more quality research articles. To do this, the study performs a survey using three keywords; namely “green construction”, “green building” and “sustainable building” on Scopus database and found 8692 articles over the period 1965-2019 where one of these keywords, at least, was used in their abstracts, keywords or titles. We also use three measures of h-index, I-10 and total publications repre-sentative of quality and quantity of the outputs produced by researchers. The study considers 28 countries responsible for at least 90% of CO2 emission for measuring the relative efficiency program using data envelopment analysis. The results indicate that Hong Kong was the only efficient country followed by Singapore with relative efficiency of 0.67.