A 485-million-year history of Earth’s surface temperature
Level 4 - case-series / case-control
Paleoclimate modeling and observational proxy data assimilation (graded by design analogy for non-clinical research).
OpenAlex W4402625647 · doi:10.1126/science.adk3705
What was done
Researchers developed PhanDA, a continuous reconstruction of Earth's global mean surface temperature (GMST) spanning the past 485 million years (the Phanerozoic eon). The reconstruction was created by statistically integrating paleoclimate proxy data with climate model simulations using data assimilation methods.
What was found
The reconstruction revealed a GMST range of 11°C to 36°C over the 485-million-year period. Earth spent more time in warmer climate states than in colder ones, with consistent latitudinal temperature gradients observed within individual climate states. Atmospheric CO2 concentrations correlated strongly with GMST, establishing CO2 as the primary driver of Phanerozoic climate variations and indicating an apparent Earth system sensitivity of ~8°C.
Why it matters
This reconstruction provides a continuous deep-time temperature record across the Phanerozoic, establishing the dynamical bounds of Earth's climate system and reinforcing atmospheric CO2 as the primary determinant of long-term global temperature.
Limits
The abstract does not provide specific sample counts, proxy types, or temporal resolution metrics. The findings rely on paleoclimate proxies, which carry inherent uncertainties related to preservation bias, calibration errors, and uneven geographic distribution, combined with model-based data assimilation assumptions.
Cited by
- context There have been periods in Earth's history when atmospheric carbon dioxide levels were significantly higher than today while global temperatures were significantly colder.