Global Climate Change and Regional Vulnerability: Quantifying CO2–Temperature–Precipitation Interactions with a Focus on Armenia

Understanding how global climate drivers manifest at regional scales is critical for designing targeted adaptation strategies, particularly in vulnerable mountainous countries. This study provides an integrated assessment of atmospheric CO2 concentrations, surface temperature, and precipitation trends at both global and Armenian levels from the early 20th century to 2024. Using long-term observational datasets and ordinary least squares regression models with HAC-robust errors, this study quantifies the magnitude and statistical significance of historical climate shifts. Results confirm pronounced global warming (+0.021 °C/year) alongside a moderate rise in global precipitation (+1.13 mm/year). Armenia, however, exhibits substantially accelerated warming (+0.052 °C/year) coupled with a non-significant and spatially heterogeneous precipitation trend, including notable declines in humid regions. CO2 emissions per capita strongly predict temperature change both globally (0.59 °C/ton) and, even more prominently, in Armenia (1.33 °C/ton), indicating heightened regional climate sensitivity. These findings align closely with Armenia’s Fourth National Communication to the UNFCCC, reinforcing the robustness of the analysis. By revealing how global climate forcings translate into region-specific outcomes—and by discussing the emerging thermal contribution of digital infrastructure—this study underscores the urgency of localized climate adaptation, water resource planning, and agricultural resilience measures.