Nowadays one of the crucial issues facing the planet is climate change. Carbon dioxide (CO2) emissions have the largest weight in the GHG (greenhouse gases) category being, at the same time, the most important factor responsible for all the repercussions caused by climate change. In the industrial field, the energy sector is the major producer of GHG emissions and especially of CO2 emissions. Therefore, decision factors at a global level are concentrating the efforts to diminish CO2 emissions both in production and in use of energy. The efficient use of renewable energy and the encouragement of the use of alternative sources and carbon-free renewable energies aiming at climate neutrality, are the next targets set at the global level, at the EU level and later at the national level. Sustainable development and economic progress, both in developed and emerging countries, should be based on two key fundamental elements: pollution reduction and energy security. evolution of carbon accumulation intensity in Latin America and the Caribbean De Oliveira-De Jesus (2019), while İpek Tunç presented the Turkish case (İpek Tunç, 2009). In Romania, the decomposition method was used to analyze the relationship among PM10, PM2.5 and N2O and several skin and respiratory diseases, tumors and attempt to establish the impact of pollutants on population health Andrei et al. (2021), Nastase et al. (2018). The present study is the first article that analyzes five driving factors: CO2 emissions, primary energy resources, energy consumption, GDP and population from the period 2008-2022 using the log mean Divisia index in Romania. The general evaluation of recent studies and anterior analyses in the context of Romanian demonstrates that despite the fact that several authors tried to examine the factors impacting carbon emissions in the country, none of the study employed LDMI technique to decompose carbon emission factors. Consequently, to complete information gaps and to present correct and trustworthy evidence, it is essential to use LMDI decomposition procedure to decompose factors influencing CO2 emissions in the circumstances of Romania. Referring to decomposition analysis we use LMDI method developed by Ang (2005) and the Kaya identity equation Kaya (1989), to find out the leading factors that influence to the change in CO2 emissions in the Romanian economy during 2008-2022. The research accomplished in this paper utilizes the yearly data series collected by the National Institute of Statistics of Romania (TEMPO Online database for Romania), for the five indicators NISR (2022) . By the reason of the limitations of data, we consider the contribution of primary energy resources, energy consumption, GDP and population toward carbon emissions at the national level. In this paper, carbon emission factor decomposition model based on LMDI method has been applied. The study used the next formula (1) in order to decompose carbon emissions in Romania: (2) In formula (2): ΔC indicates the difference between CO2 emission Ct in the year t and C0 in the basis year 0; ΔI indicates the contribution of C/F in formula (1) to ΔC. And it is defined as carbon intensity effect; Consequently, ΔM represents the contribution of F/E and is defined as energy mixes effect; ΔL indicates the contribution of E/G and is defined as generating efficiency effect; ΔB indicates contribution of G/P and is defined as economic effect; ΔP indicates the contribution of P and is defined as population effect. And to simplify the calculation, A is defined as follows:

(3) To assess the contribution to the modification of CO2 emissions, five indexes can be computed during every interval in this way:

The index increases the CO2 emissions when the contribution is positive and oppositely, if the contribution rate is negative, it implies that the index diminishes CO2 emissions. The CO2 emissions resulted from economic activities were calculated based on formula (1). Overall, the biggest decrease is between 2008 and 2009 with a difference of 19828 Gg tons, following during the period 2010-2012 a fairly significant increase of 7646 Gg tons and then until 2022 the trend was obviously decreasing. Starting with 2010 and until 2013, Romania passes through an economic crisis and investments in environmental protection were reduced, followed by a very important period with non-reimbursable European investments at the same time correlated with legislative impositions at the EU level. For the purpose of describing the driving forces of CO2 emissions, this subsection analyzes the contribution of carbon intensity (ΔI), energy mixes (ΔM), generating efficiency (ΔL), economy (ΔB), and population (ΔP). Table 1 presents the results, calculated by the LMDI technique in formula ( 4)-( 8). Between them, the positive values indicate the expansion effect on CO2 emissions. On the contrary, the negative values indicate the restraining effect. Note: The contribution share of each index is shown in its below bracket. In order to get an overview of the driving forces of CO2 emissions, we have represented graphically in figure no. 2 the contribution of carbon intensity (ΔI), energy mixes (ΔM), generating efficiency (ΔL), economy (ΔB), and population (ΔP), for the entire analyzed period. In Table 1, the largest positive index was ΔB, accounting for 34.94% of the overall CO2 emission change of the energy use in Romania from 2008 to 2022. After the end of the communist period, along with the development of the reform the Romanian economy developed relatively constantly. The non-reimbursable European funds are a basic element of the development of the national economy, the purpose of these funds being the creation of more jobs, ensuring a solid European economy and a healthy environment. On the other hand, economic growth also has a flip side, the use of resources and environmental pollution. As indicated in Figure 3 from 2008 to 2022, Romania's GDP had steadily increased, with a yearly average growth rate at 3.25%, with variations from -5% to 9.3% compared to the previous year.
In the analyzed period there were three situations with a negative percentage compared to the previous year, namely 2009 with -5.5% compared to 2008 and -3.9% in 2010 compared to 2009, and the last situation being the one from 2020 with a percentage of -3.7% compared to 2019. In the first two situations we are talking about the economic crisis that our country went through in that period, and the third situation about the COVID pandemic that had a major economic impact worldwide. In total, Romania's GDP increased from 539,834 million lei in 2008 to 1,409,783 million lei in 2022, which represents an increase of almost three times the initial amount. Generally speaking, the economic effect assessed the impact of economic development which is related by the immediate process of industrialization and increased consumption of energy. If we refer to the population, in the last three decades there has been an important phenomenon of agglomeration of citizens in areas with economic growth and the depopulation of some cities and villages where there were no longer profitable economic activities. Consequently, the responsibility of energy saving and emission decreasing in Romania is more demanding. At the national level is essential to stimulate the industrial renewal and upgrading to achieve the common development among economy, society and environment to reduce CO2 emissions within the economic progress. The large industrial centers in the metallurgical, thermo-energetic or machine building sectors, resource and energy consuming industries have gradually ceased their activities, their place being taken over by a series of investments that must comply with the European impositions regarding the maximum allowed limits of pollutants. The smallest positive index was ΔP, accounting for 3.72% of the overall CO2 emissions. Romania's population has gradually decreased from 20635460 inhabitants in 2008 to 19042455 inhabitants in 2022. As a percentage, the population decrease is only 7.71%, more precisely the difference is 1593005 inhabitants. Generally, CO2 emissions were greatly correlated with the number of resident population, being visible in the quantity of the energy consumption both as well the aspect of residential request. In the last decade, the population's demand for electricity has become increasingly high due to the use of electronic and household appliances, lighting and heating installations for residential, industrial and administrative spaces. Although the number of resident population has decreased, energy consumption is constantly increasing, reason for which the contribution of citizens to CO2 emissions might not reduce considerably in the coming years. For that reason, enhancing residents' perception of energy savings and ecological modernization may diminish CO2 emissions. The largest negative index was ΔL, accounting for -46. 1, and oppositely. 2009-2010 is the only period when a positive coefficient was recorded, the explanation being that both the production and consumption of electricity increased compared to previous years, according to the official reports of the National Energy Regulatory Authority. Romania inherited from the period of the centralized economy a highly intensive structure of the economy and implicitly a very high intensity of primary energy. Advances in technology had a positive effect on the CO2 emissions. Beside the constant development in technics and efficiency, energy utilization reduced, thus decreasing CO2 emissions. The second largest positive index was ΔM, accounting for 7.44% of the total emission change. It was negative correlated with CO2 emission, opposite with ΔL. Taking into account a specific quantity of energy consumption, the preponderant the weight of fossil-based energy was, the fewer renewable energy was utilized, and the larger CO2 emission was recorded. On the other hand, increasing the proportion of renewable energy might decrease CO2 emissions. In the period 2008-2022, the main types of primary energy resources used by different sectors of the economy were: crude oil 22%, natural gas 22%, coal 12%, hydroelectric, nuclear and imported electricity 10% and firewood 10%. ΔI was the second largest negative index, accounting for -12.15% of the total emission change. This index the carbon intensity is related to the complete types of energy sources, both fossil energy and renewable energy, and more than that, the quantities of energy imported during this period were also included in the calculations. According to the literature the carbon intensity differs from various mixes of fossil fuels, for example, diesel and gasoline are more carbon intensive than raw coal, that are furthermore carbon intensive comparing with natural gas. Conversely, using renewable energy such as solar, wind and hydro energy might not release CO2, and in this period the percentage of renewable energy produced and imported is only 11%. In this paper, the influencing factors of CO2 emissions from the energy use in Romania were calculated by LMDI method of decomposition. The analysis also considers the impact of different energy sources used: crude oil, natural gas, coal, hydroelectric, nuclear and imported electricity and firewood. The five components of the change in CO2 emissions an al y zed in this study were carbon intensity (ΔI), energy mixes (ΔM), generating efficiency (ΔL), economy (ΔB) and population (ΔP). Among them two positive factors (ΔB and ΔM) have the expanding effect on CO2 emissions while the three negative factors (ΔL, ΔP and ΔI) having the inhibiting effect. From 2008-2022, economic progress was the major factor impacting the increase of total CO2 emissions from the energy utilization. On the contrary, enhancing energy efficiency was the most important factor to prevent emissions. Improving energy system and decreasing carbon intensity furthermore had impeding consequences on emissions. Our paper shows that, the principal component that influence the changes in CO2 emissions in Romania is the economic activity and by contrast the generating efficiency effect is the largest negative index. Predominantly it can be observed that emissions are cyclical, CO2 emissions rise at the time that the economy increase and reduce when the economic activity constrict, the most obvious index being ΔI carbon intensity effect.
Nevertheless, we also notice an essential modification in the structure of the economy during 2008-2022 interval, like for example the economic crisis that our country went through between 2008-2010 and the effects of the COVID 19 pandemic are evident in our analyses. All the five indexes studied showed variations in the transition from 2008 to the other years, probably due to the changes in the structure of large sectors of the Romanian economy under the impact of EU accession, as well as the gaps between the sectors of the economy in terms of labor productivity. The main conclusions outlined from the present study may be summarized as follows:

(1) GDP increased three times in the period 2008-2022 from 539835 million lei to 1409784 million lei and ∆B Economic effect varies from -611.18 to 10697.27 (2) The resident population in Romania decreased from 20635460 inhabitants to 19042455 inhabitants also the index ∆P Population effect decrease from -807.04 to -494.82 (3) Primary energy resources vary from 48166 thousands of tons of oil equivalent to 41562 thousands of tons of oil equivalent while ∆M Energy mixes effect ranges within the following limits 17098.44 1436.76 (4) Energy consumption fluctuate from 18230 thousands of tons of oil equivalent to 13289 thousands of tons of oil equivalent and the index ∆L Generating efficiency effect range from -25852.18 to -12012.68 (5) ∆I Carbon intensity effect index decreased from -9656.05 to -1219.73 Although, due to the difficulties in data acquisition and analysis, this article has some limitations, it is nevertheless a first analysis of the situation in Romania using the LDMI method for the period 2008-2022. A number of presumption made in this study may insignificantly bias the results, but future studies must focus on a more comprehensive analysis of all environmental and economic benefits. This data may have realistic value for encouraging economic progress with low carbon emissions, especially in the context of climate neutrality that is imposed in the period 2030-2050 having a proper balance between environmental protection, social, and economic targets. The significance of our study is its feasible application to assist government and local authorities to develop best decision policies for improved air quality control in Romania. Every factor has distinct effect on CO2 emissions throughout separate intervals. The LMDI evaluates CO2 emissions by multiple types of specific indexes in addition or multiplication decomposition. Based on formula (1), after logarithmic transformation, the cumulative function