4. Results and Discussion
4.1. Descriptive Statistics
Table 2 presents the descriptive statistics for the variables used in examining the contribution of green energy transition, technological innovation, and green finance to carbon neutrality in BRICS countries over the period 1990–2024. All variables are transformed into logarithmic form to ensure consistency, reduce heteroskedasticity, and improve normality. The mean value of carbon emissions (LNCO₂) is 1.28, accompanied by a standard deviation of 0.96 and a maximum value of 2.64, reflecting a moderate degree of variation among BRICS economies. This suggests that although the overall emission levels are relatively balanced across countries, there remains a noticeable disparity, with some economies exhibiting higher emissions due to variations in industrial development and energy consumption structures. However, green energy transition (LNGET), proxied by renewable energy consumption, has a mean of 3.02, a standard deviation of 0.74, and a maximum value of 3.97, reflecting a gradual yet uneven adoption of renewable energy technologies among member countries.
Technological innovation (LNTI) reports an average value of 8.52, with a relatively high standard deviation of 2.37 and a maximum of 14.36, indicating a substantial disparity in innovation performance among BRICS nations. This heterogeneity is mainly driven by differences in R&D investment, technological capabilities, and institutional support. For instance, China demonstrates significantly higher patent activity due to its strong innovation ecosystem and policy support, whereas India and other emerging economies exhibit relatively lower levels of green patent development due to resource and infrastructure constraints
Green finance (LNGF) shows a mean value of −0.43, a relatively high standard deviation of 1.47, and a maximum of 2.90, indicating substantial disparities in financial sector development and the mobilization of sustainable finance across BRICS countries..
Economic growth (LNGDP) has an average of 8.07, with a standard deviation of 0.98 and a maximum value of 9.48, reflecting relatively stable but differentiated income levels across BRICS economies. This moderate variation is primarily driven by differences in economic size, industrial structure, and growth trajectories.
Trade openness (LNTO) records a mean of 3.70, a low standard deviation of 0.32, and a maximum of 4.19, suggesting relatively stable trade integration among BRICS countries
4.2. Correlation Analysis
Table 3, reports the correlation coefficients among the variables. Carbon emissions (LNCO₂) are negatively correlated with green energy transition (-0.91), technological innovation (0.02), and green finance (-0.44), suggesting that improvements in renewable energy use, innovation capacity, and sustainable finance are associated with lower emission levels in BRICS countries.
Conversely, economic growth (0.73) and trade openness (0.58) show positive correlations with emissions, indicating that expansion in economic and trade activities may increase environmental pressure. The correlation values remain below 0.95, confirming the absence of severe multicollinearity among the explanatory variables. Weak correlations close to zero (e.g., between trade openness and technological innovation, -0.05) indicate limited direct association between these variables.
4.3. Slope Homogeneity Test
The slope homogeneity test confirms the presence of significant heterogeneity across BRICS countries, indicating that the impact of explanatory variables on carbon emissions varies substantially among member economies. This heterogeneity reflects differences in economic structure, energy mix, institutional quality, and the level of technological and financial development. In particular, the emission reduction effect of green energy transition is not uniform across countries. Economies with a higher share of renewable energy in their energy mix tend to experience stronger emission reductions, while countries with continued reliance on fossil fuels exhibit relatively weaker effects. Similarly, the effectiveness of technological innovation varies depending on the orientation of innovation activities—whether they are directed toward green technologies or conventional industrial expansion. Green finance also demonstrates heterogeneous impacts across BRICS countries due to variations in financial market maturity, regulatory frameworks, and the scale of sustainable investments. In economies where green financial systems are more developed, the allocation of capital toward environmentally friendly projects is more efficient, resulting in stronger environmental outcomes. In contrast, countries with emerging or less developed green finance frameworks experience limited short-term benefits. Trade openness further contributes to heterogeneous outcomes through differing compositions of trade and industrial specialization. Countries exporting cleaner technologies or less energy-intensive goods may benefit from reduced emissions, whereas those specializing in resource- or energy-intensive exports may experience increased environmental pressure. These heterogeneous patterns are consistent with existing literature. Acemoglu et al. (2012) emphasize that the environmental impact of technological change depends on its direction and policy support. Stern (2007) highlights that structural and institutional differences across countries significantly influence the effectiveness of climate mitigation strategies. Additionally, Frankel and Rose (2005) argue that the environmental effects of trade openness vary depending on country-specific economic characteristics.
Table 4 and
Table 5, the study examines the stationarity properties of the selected variables after establishing the presence of cross-sectional dependence (CSD) and slope heterogeneity. Accordingly, the CIPS, CADF and Levin et al. (2002 unit root tests are employed, as both tests yield reliable and consistent results in the presence of CSD and heterogeneous slopes.
4.5. Panel Unit Root Test
To determine the order of integration of the variables, second-generation panel unit root tests are applied in
Table 6, considering slope heterogeneity and cross-sectional dependence among BRICS countries (Brazil, Russia, India, China, and South Africa). The Cross-Sectionally Augmented IPS (CIPS), Cross-Sectionally Augmented Dickey-Fuller (CADF), and Levin et al. (2002) tests are employed. The null hypothesis assumes that the variables are non-stationary.
Table 6, The results of the CIPS, CADF, and Levin et al. (2002) tests indicate that all unit root tests using a consistent specification based only on the individual intercept become stationary at both level and first differences. This suggests that the variables are integrated of mixed order, implying the possible existence of a long-run cointegration relationship among them.
4.6. Westerlund (2007) Panel Cointegration Test
Following the application of unit root tests, the study proceeds to investigate the presence of long-run cointegration. Accordingly, the Westerlund cointegration test is employed, and the estimated results are reported in
Table 7. The findings indicate that all variables are cointegrated in the long run, as evidenced by both the panel and group statistics.
The Gt and Ga statistics test cointegration at the individual country level, while Pt and Pa test cointegration at the panel level under the null hypothesis of no cointegration. The majority of statistics reject the null hypothesis, confirming the presence of a long-run equilibrium relationship among the variables. The confirmation of cointegration implies that green energy transition, technological innovation, and green finance have a stable long-term association with carbon emissions in BRICS countries. Consequently, the PMG-ARDL approach is employed to estimate long-run and short-run dynamics. The selection of PMG-ARDL is justified by its suitability for small sample sizes and its ability to handle mixed integration orders while allowing short-run heterogeneity across countries. The long-run estimation results are presented in
Table 8.
4.7. PMG-ARDL Long Run Analysis
PMG-ARDL results for BRICS countries, using D(LCO2) as the dependent variable over the period 1990–2024 (145 observations), with the optimal lag structure selected based on the Akaike Information Criterion (AIC). The ARDL(1,1,1,1,1) model is identified as the preferred specification, incorporating LNGET, LNTI, LNGF, LNGDP, and LNTO with one lag each along with a constant term, ensuring a parsimonious and well-fitted framework.
In the long run, Green Energy Transition (LNGET) has a negative and statistically significant coefficient (-0.45) at the 1% level. This implies that a 1% increase in renewable energy consumption reduces carbon emissions by approximately 0.45%, confirming the crucial role of renewable energy in achieving carbon neutrality. The empirical findings indicate that Green Energy Transition (LNGET) has a negative and statistically significant impact on carbon emissions in the long run, suggesting that an increase in renewable energy consumption contributes to environmental improvement. From a theoretical perspective, this result supports the ecological modernization theory, which argues that technological innovation and cleaner energy systems can reduce environmental degradation while sustaining economic development. It also aligns with the energy transition framework, which emphasizes the gradual shift from fossil-fuel-based energy systems toward renewable and sustainable energy sources to achieve carbon neutrality. Several studies have documented a negative relationship between renewable energy consumption and carbon dioxide emissions. Increasing the share of renewable energy significantly reduces environmental pollution and promotes sustainable development (Huang et al., 2021; Polat & Kızılkan, 2022; Hasnisah et al., 2019). While some empirical studies report a positive relationship between renewable energy consumption and carbon dioxide emissions, particularly in developing economies where fossil fuels still dominate the energy mix and renewable energy adoption remains limited (Sadorsky, 2009; Apergis & Payne, 2010; Zhang & Cheng, 2009; Pata, 2018).
However The long-run coefficient of technological innovation (LNTI) is negative and statistically significant (−0.17), indicating that a 1% increase in technological innovation leads to a 0.17% reduction in carbon emissions in the long run. This finding suggests that technological progress plays a crucial role in improving environmental quality by promoting energy efficiency and facilitating the adoption of cleaner production techniques. The negative relationship explained by the technological innovation enhances the development and diffusion of low-carbon technologies, such as renewable energy systems, energy-efficient industrial processes, and carbon capture mechanisms. Over time, these innovations reduce reliance on fossil fuels and lower overall emissions. However, the impact of technological innovation is typically observed in the long run rather than the short run, as it requires time for research and development, commercialization, and large-scale adoption. These findings are consistent with prior studies that highlight the role of innovation in environmental sustainability. For instance, Aghion et al. (2016) argue that green innovation is essential for achieving sustainable growth and reducing emissions. Similarly, Wang, et. al., (2019) find that technological advancements significantly contribute to carbon emission reduction in emerging economies.
Similarly, The long-run coefficient of green finance (LNGF) is negative and statistically significant (−0.10), indicating that a 1% increase in green finance leads to a 0.10% reduction in carbon emissions in the long run. This result suggests that green financial development plays a vital role in promoting environmental sustainability by channeling investments toward environmentally friendly projects.
The negative relationship can be explained by the fact that green finance facilitates funding for renewable energy projects, energy-efficient technologies, and sustainable infrastructure. Over time, such investments help reduce dependence on fossil fuels and improve environmental performance. However, the impact of green finance is more pronounced in the long run, as financial markets require time to mature, and green investments often have delayed environmental returns.
These findings are supported by previous studies. For instance, Zetzsche, et al. (2022) highlight the importance of green finance in supporting sustainable development and climate mitigation. Likewise, Lee, (2020) emphasizes that green financial policies and instruments significantly contribute to reducing carbon emissions by directing capital toward low-carbon sectors.
Conversely, The long-run coefficient of economic growth (LNGDP) is positive and statistically significant (0.43), indicating that a 1% increase in GDP leads to a 0.43% increase in carbon emissions in the long run. This result suggests that economic expansion in the sampled economies is associated with higher environmental pressure, primarily due to increased energy consumption and industrial activities.
The positive relationship explained by the fact that, in the early and middle stages of development, economic growth is often driven by energy-intensive industries and fossil fuel consumption. As production, urbanization, and infrastructure development expand, the demand for energy rises, leading to higher carbon emissions. This phenomenon is consistent with the early phase of the Environmental Kuznets Curve, which posits that environmental degradation increases with economic growth before eventually declining at higher income levels.
These findings are supported by existing literature. For example, Grossman and Krueger (1995) demonstrate that economic growth initially leads to environmental degradation. Similarly, Muhammad et al. (2021) find that economic growth significantly increases carbon emissions in developing and emerging economies due to reliance on conventional energy sources.
However, the long-run coefficient of trade openness (LNTO) is negative and statistically significant (−0.87), indicating that a 1% increase in trade openness leads to a 0.87% reduction in carbon emissions in the long run. This finding suggests that greater integration into the global economy contributes to environmental improvement over time.
The negative relationship explained through the technology transfer and efficiency effect. Increased trade openness allows countries to access advanced and cleaner technologies from developed economies, which enhances production efficiency and reduces carbon intensity. Moreover, exposure to international markets encourages firms to adopt environmentally friendly standards and practices to remain competitive. Over time, this leads to a transition toward cleaner production processes and lower emissions.
These results are supported by existing literature. For instance, Frankel and Rose (2005) argue that trade openness improve environmental quality through income and technique effects. Similarly, Copeland and Taylor (2004) highlight that international trade promotes cleaner technologies and reduces pollution in the long run.
4.8. PMG-ARDL Short Run Analysis
In the short-run coefficient of green energy transition (LNGET) is negative and statistically significant (−5.65), indicating that an increase in green energy transition leads to a substantial reduction in carbon emissions in the short run. This result suggests that shifting from fossil fuels to renewable energy sources has an immediate and direct impact on reducing environmental pollution.
The negative relationship explained by the fact that green energy transition involves the replacement of carbon-intensive energy sources, such as coal and oil, with cleaner alternatives like solar, wind, and hydro energy. Unlike other variables, renewable energy adoption produces an instantaneous effect on emissions, as it directly reduces the carbon intensity of energy consumption. Therefore, even in the short run, increased reliance on clean energy significantly lowers CO₂ emissions.
These findings are supported by previous literature. For instance, Stern, N. (2008) highlights that transitioning to low-carbon energy systems is essential for immediate and long-term climate mitigation. Similarly, Downie, C. (2020) emphasizes that renewable energy deployment leads to rapid reductions in carbon emissions due to its direct substitution effect over fossil fuels.
However The estimated coefficient of technological innovation (TI) is 2.45, indicating a positive but statistically insignificant relationship with carbon emissions in the short run. This suggests that a 1% increase in technological innovation is associated with an approximate 2.45% change in carbon emissions; however, technological innovation is positively associated with changes in carbon emissions in the short run, its effect is statistically insignificant due to delayed implementation and diffusion processes. In countries such as China and India, a significant share of innovation is initially directed toward enhancing industrial productivity and economic growth rather than environmental sustainability. Moreover, the commercialization and large-scale deployment of green technologies require time, investment, and supportive institutional frameworks. In addition, the “rebound effect” may arise in the short run, where efficiency improvements lower production costs and stimulate higher output and energy consumption, thereby offsetting emission reduction gains. Over time, however, as cleaner technologies mature, energy efficiency improves, and environmental regulations tighten, technological innovation exerts a more pronounced and statistically significant negative effect on carbon emissions. This outcome to the fact that the environmental benefits of technological innovation are not realized immediately, as they require sufficient time for development, diffusion, and effective implementation (Zhang, 2010; Zhao et al., 2016; Li & Yue, 2024). Consequently, the impact of technological innovation becomes more pronounced and statistically significant in the long run.
Moreover The short-run estimates reveal that green finance exerts a negative but statistically insignificant effect on carbon emissions, with a coefficient of −3.49. This implies that a 1% increase in green finance is associated with an approximate 3.49% reduction in carbon emissions; however, the absence of statistical significance suggests that this effect is not robust in the short term. In the context of BRICS economies, this can be explained by cross-country heterogeneity, as these five countries differ significantly in terms of financial market development, institutional quality, and the maturity of green finance frameworks. While some countries have relatively advanced green financial systems, others are still in the early stages, leading to uneven allocation and utilization of green funds. This variation offsets the overall short-run impact and results in statistical insignificance. This finding the underdeveloped nature of green financial markets and the time required for the effective allocation and utilization of green funds in environmentally sustainable projects (Aghion et al., 2016; Li & Yue, 2024). Consequently, the environmental benefits of green finance tend to materialize more prominently in the long run.
Similarly, the short-run estimates indicate that a 1% increase in economic growth leads to a 7.43% rise in carbon emissions; however, this effect remains statistically insignificant. This suggests that although economic expansion tends to increase energy demand and emissions, its immediate environmental impact is not sufficiently strong to yield a statistically robust relationship in the short term. This may be due to structural adjustments, policy interventions, and transitional dynamics in BRICS economies, where the scale effect of growth is partially offset by improvements in energy efficiency and gradual adoption of cleaner technologies (Grossman & Krueger, 1995; Selden & Song, 1994). Consequently, the impact of economic growth on carbon emissions becomes more evident and statistically significant over the long run as these structural effects fully materialize.
In the case of trade openness, the short-run results indicate that a 1% increase leads to a 4.33% rise in carbon emissions; however, this relationship is statistically insignificant. This suggests that while increased trade may initially contribute to higher emissions through the scale effect—by expanding production and energy consumption—the immediate impact is not sufficiently strong to establish statistical significance. In the short run, the environmental effects of trade openness remain ambiguous, as the potential pollution-enhancing effects are often offset by efficiency gains, regulatory adjustments, and gradual technology transfer processes in emerging economies such as the BRICS countries (Grossman & Krueger, 1995; Bhagwati, 1993). Consequently, the impact of trade openness on carbon emissions becomes more pronounced and statistically significant in the long run as structural transformations and environmental policies take full effect.
In contrast, the error correction term (ECT−1 = −0.76**) implies that approximately 76% of the short-run disequilibrium is corrected within a single period, indicating a strong speed of adjustment toward the long-run equilibrium.
4.9. FMOLS and DOLS Robustness Test
Table 9, ensure the robustness of the long-run estimates, the study employs Fully Modified Ordinary Least Squares (FMOLS) and Dynamic Ordinary Least Squares (DOLS) estimators. These techniques effectively control for endogeneity and serial correlation, thereby providing reliable and efficient long-run coefficients. The empirical findings reveal a strong degree of consistency across both estimators. Green Energy Transition (LNGET) exhibits a negative and statistically significant impact on carbon emissions, with coefficients of −0.27 (p = 0.00) under FMOLS and −0.37 (p = 0.04) under DOLS, confirming its effectiveness in reducing environmental degradation. Similarly, Technological Innovation (LNTI) shows a negative relationship, with coefficients of −0.04 (p = 0.03) in FMOLS and −0.09 (p = 0.09) in DOLS, indicating that innovation contributes to emission reduction, albeit with slightly weaker significance in the latter model. Green Finance (LNGF) also demonstrates a consistent negative effect, with estimated coefficients of −0.02 (p = 0.02) in FMOLS and −0.12 (p = 0.08) in DOLS, highlighting its role in promoting environmental sustainability. In contrast, Economic Growth (LNGDP) exerts a positive and statistically significant influence on emissions, with coefficients of 0.64 (p = 0.08) and 0.49 (p = 0.01) in FMOLS and DOLS, respectively, suggesting that higher economic activity is associated with increased carbon emissions. However, Trade Openness (LNTO) presents mixed evidence. While it is positive and significant in the FMOLS model with a coefficient of 0.69 (p = 0.04), it becomes statistically insignificant in the DOLS estimation (0.38, p = 0.14), indicating that its impact may be sensitive to model specification
4.10. Dumitrescu–Hurlin (DH) Panel Causality Test
Table 10, report the Dumitrescu–Hurlin panel causalty results reveal important dynamic interactions among the variables. There is unidirectional causality from Green Energy Transition to carbon emissions, indicating that renewable energy policies actively drive emission reductions in BRICS countries.
Similarly, technological innovation Granger-causes emissions, confirming that innovation-led environmental improvements play a decisive role in advancing carbon neutrality. Green finance also demonstrates unidirectional causality toward emissions, implying that sustainable financial mechanisms directly influence environmental performance. A bi-directional causality between economic growth and emissions is observed, reflecting the growth–environment nexus in BRICS economies. Meanwhile, trade openness shows weak or insignificant causal influence on emissions. Collectively, these findings emphasize that green energy transition, technological innovation, and green finance are not only statistically significant determinants but also dynamic drivers of carbon neutrality in BRICS countries.