## 5 Results
### Mediating Effects Analysis
#### 5.2.3 Empirical Test of the Mediating Effect of Public Ecological Awareness  
The results for the impact of GPP expenditures on urban carbon emissions intensity mediated by public ecological awareness are reported in Table 5. In Column (1), GPP has a total effect of \(-\)1.548 on urban carbon emissions intensity (\(p\) < 0.01). In Column (3) with public ecological awareness included, the direct effect decreases to \(-\)1.460 but remains significant (\(p\) < 0.01). This highlights the robustness of our findings.  
\begin{table}
\begin{tabular}{l l l l} \hline  & **(1) Urban Carbon** & **(2) Corporate Sustainability** & **(3) Urban Carbon** \\  & **Emissions Intensity** & **Performance** & **Emissions Intensity** \\ \hline Green public procurement & \(-\)1.548 *** & 1.206 *** & \(-\)1.115 *** \\  & (0.402) & (0.318) & (0.401) \\ Corporate sustainability & & & \(-\)0.171 *** \\ performance & & & (0.028) \\ Control Variables & Yes & Yes & Yes \\  & \(-\)10.212 *** & 26.097 * & \(-\)54.139 *** \\ Constant & (2.494) & (15.105) & (19.008) \\ Individual Fixed Effects & Yes & Yes & Yes \\ Temporal Fixed Effects & Yes & Yes & Yes \\ N & 2565 & 2565 & 2565 \\ R-squared & 0.633 & 0.059 & 0.649 \\ \hline \end{tabular} Notes: Standard errors in parentheses. All variables mean-centered. * \(p\) < 0.1, *** \(p\) < 0.01.  
\end{table}
Table 4: Mediating effect of corporate sustainability performance.  
\begin{table}
\begin{tabular}{l l l l} \hline  & **(1) Urban Carbon** & **(2) Public Ecological** & **(3) Urban Carbon** \\  & **emissions Intensity** & **Awareness** & **Emissions Intensity** \\ \hline Green public procurement & \(-\)1.548 *** & 0.004 ** & \(-\)1.460 *** \\  & (0.402) & (0.002) & (0.401) \\ Public ecological awareness & & & \(-\)20.543 *** \\  & & & (4.549) \\ Control Variables & Yes & Yes & Yes \\  & \(-\)10.212 *** & 0.174 *** & \(-\)6.645 ** \\ Constant & (2.494) & (0.011) & (2.606) \\ Individual Fixed Effects & Yes & Yes & Yes \\ Temporal Fixed Effects & Yes & Yes & Yes \\ N & 2565 & 2565 & 2565 \\ R-squared & 0.633 & 0.619 & 0.636 \\ \hline \end{tabular}
\end{table}
Table 5: Mediating effect of public ecological awareness.  
In terms of the mediation mechanism, Column (2) reveals that GPP significantly boosts public ecological awareness, thereby meeting the first-stage condition for testing mediation effects. This suggests that GPP signals the government's commitment to environmental governance and strengthens societal engagement in climate risk policies. The mediation test results in Column (3) indicate that increased public ecological awareness is negatively associated with urban carbon emissions intensity. The Sobel test (\(z=-2.83\), \(p<0.01\)) and Bootstrap method (95% CI [\(-0.019\),\(-0.005\)]) validate this mediating path, thus supporting H4.  
Notably, the mediating effect of GPP, which enhances public ecological awareness, accounts for 5.31%3 of the total effect. This indicates that while public ecological awareness significantly contributes to the mediation process, it does not operate in isolation. Although its impact (5.31%) is less than that of corporate sustainability performance (13.32%), the importance of \"government-public\" collaborative governance in achieving carbon neutrality goals is highlighted. Public engagement may reduce urban carbon emissions intensity through two mechanisms. First, enhanced environmental awareness induces a shift in consumer demand toward low-carbon certified products, leveraging market mechanisms to drive emission reductions [60]. Second, increased public participation in environmental oversight generates informal regulatory pressure, which in turn constrains corporate carbon emissions through channels such as complaints and feedback mechanisms [61].  
Footnote 3: [[https://www.census.org/](https://www.census.org/)]([https://www.census.org/](https://www.census.org/))