The CO2-temperature coupling across scales: a critical review from Arrhenius 1896 to the Anthropocene | Zenodo Skip to main Communities My dashboard Log in Sign up Published April 26, 2026 | Version v1 Preprint Open The CO2-temperature coupling across scales: a critical review from Arrhenius 1896 to the Anthropocene Authors/Creators Ganan-Calvo, Alfonso (Project leader) 1 Show affiliations 1. Universidad de Sevilla Description This review articulates the CO$_2$--Global Mean Surface Temperature (GMST) coupling within a phase-space framework anchored to the 1896 Arrhenius logarithmic law, read as a function of the averaging window $\Delta t$. GMST is inferred from benthic $\delta^{18}$O over the Cenozoic and surface reanalyses in the Anthropocene. The aim is structural rather than parametric: to identify the geometric organisation across timescales, not to advance a new equilibrium climate sensitivity estimate. On timescales $\Delta t \gtrsim 5.5$~Ma, the post-hyperthermal 0--50~Ma Cenozoic is compatible with the historical Arrhenius benchmark $\alpha_{\mathrm{Arr}} \approx 7.755\,^{\circ}$C per CO$_2$ $e$-folding; a formal fit gives $\alpha_{\mathrm{fit}} \approx 8.5\,^{\circ}$C, within the feedback-corrected range $\alpha_{\mathrm{AESS}}/F \approx 7.4$--$8.9\,^{\circ}$C implied by Judd~et~al.\ (2024) and Hansen~et~al.\ (2023). On orbital timescales (20--400~kyr) the trajectory populates a wedge between the Arrhenius attractor and a Henry's-law dissolved-CO$_2$ isoline at $\approx$10~\umolL{}, the lower bound of the RuBisCO Form~I kinetic-limitation window, manifesting hierarchically through enzyme $K_m$, C4 selective pressure, and the alkenone proxy limit. The wedge closes onto the Plio-Pleistocene vertex. In the Anthropocene, the trajectory departs as a near-horizontal filament; a single thermal lag $\tau \approx 35$~yr places the instrumental record onto the Arrhenius curve within instrumental precision, consistent with the Hansen~et~al.\ (2005) thermal-inertia timescale. The implied CO$_2$-projected committed warming is $\approx 1.35\,^{\circ}$C at the Arrhenius benchmark ($0.74$--$1.48\,^{\circ}$C across the feedback-equilibration ladder); within this CO$_2$-projected reading, current temperatures are consistent with the atmospheric forcing of the early 1990s. An exploratory Phanerozoic extension using the Scotese~(2021) compilation supports the Cenozoic Arrhenius attractor and is consistent with the $\approx$10~\umolL{} floor; the logarithmic sensitivity does not extend into the Mesozoic, reproducing the Mesozoic Conundrum under one operationalisation. Files arrhenius_ESR_manuscript_v3_4.pdf Files (6.3 MB) Name Size Download all arrhenius_ESR_manuscript_v3_4.pdf md5:d2f6c1dec5c082d0c537c135c55884ab 6.3 MB Preview Download 27 Views 12 Downloads Show more details All versions This version Views Total views 27 27 Downloads Total downloads 12 12 Data volume Total data volume 76.1 MB 76.1 MB More info on how stats are collected.... Versions External resources Indexed in OpenAIRE Communities Details DOI DOI Badge DOI 10.5281/zenodo.19794567 Markdown [](https://doi.org/10.5281/zenodo.19794567) reStructuredText .. image:: https://zenodo.org/badge/DOI/10.5281/zenodo.19794567.svg :target: https://doi.org/10.5281/zenodo.19794567 HTML <a href="https://doi.org/10.5281/zenodo.19794567"><img src="https://zenodo.org/badge/DOI/10.5281/zenodo.19794567.svg" alt="DOI"></a> Image URL https://zenodo.org/badge/DOI/10.5281/zenodo.19794567.svg Target URL https://doi.org/10.5281/zenodo.19794567 Resource type Preprint Publisher Zenodo Rights License Creative Commons Attribution 4.0 International The Creative Commons Attribution license allows re-distribution and re-use of a licensed work on the condition that the creator is appropriately credited. Read more Citation Export Technical metadata Created April 26, 2026 Modified April 26, 2026 Jump up About About Policies Infrastructure Principles Projects Roadmap Contact Blog Blog Support Help FAQ Developers REST API OAI-PMH Contribute GitHub Donate Funded by Powered by CERN Data Centre & InvenioRDM Status Privacy policy Cookie policy Terms of Use This site uses cookies. Find out more on how we use cookies Accept all cookies Accept only essential cookies