Structural Persistence of the Earth Climate–Biosphere System Under Observed Anthropogenic Forcing (1851–2026)

Anthropogenic emissions of greenhouse gases have driven substantial warming of the Earth’s surface since the mid-nineteenth century. While attribution studies robustly link emissions to temperature change, less is known about whether sustained forcing has altered the fundamental organizational structure of the Earth climate–biosphere system itself. In this study, we analyze the global response of the coupled Earth system to observed national-scale emissions of CO₂, CH₄, and N₂O from fossil fuel use and land-use change over the period 1851–2026. Cumulative greenhouse gas forcing is converted to CO₂-equivalent emissions using the GWP* framework, and temperature response is evaluated using the transient climate response to cumulative carbon emissions (TCRE), consistent with IPCC AR6 best estimates. The analysis is explicitly constrained by historical emissions inventories and instrumental global mean surface temperature records through 2026. Rather than focusing on trend magnitude or scenario projections, we apply structure-aware, non-equilibrium diagnostics to evaluate regime-level properties of the Earth system, including global stability, topology invariance, causal organization, complexity, and robustness under real historical forcing. Across all diagnostics, the system converges to a stable post-emergent structural regime. Despite increasing internal variability and complexity, the global organizational topology remains invariant, with zero topology variance and a high global stability metric. These results indicate that anthropogenic forcing has reconfigured internal dynamics without inducing a global structural transition to date. This finding reframes climate risk as a problem of abrupt regime change rather than continuous structural erosion and highlights the value of regime-level diagnostics for monitoring resilience and early warning in the Earth system.