This work was a collaboration across Nanjing University, UT Austin, Purdue, UC Santa Barbara, and others.
Big thanks to our coauthors and field teams! 🙌

This has implications for understanding future warming:
📌 Fast feedbacks (like water vapor and clouds) likely dominate ECS, and these feedbacks operated similarly in cold and warm states over the past 2.6 million years.

And here's the key result:
👉 No apparent state-dependency in ECS between glacial and interglacial periods.
In other words, climate sensitivity to CO₂ forcing was remarkably consistent despite major background climate changes.

Using compiled glacial and interglacial CO₂ and temperature records, we estimate:
🌍 Earth System Sensitivity (ESS): ~6.2–7.4 K per CO₂ doubling
🌡️ Equilibrium Climate Sensitivity (ECS): ~3.3–3.7 K

Our data show a stepwise decline in glacial CO₂, from ~300 ppm to below 200 ppm.
This mirrors global cooling and the intensification of glacial cycles, suggesting a tight CO₂–climate coupling.

We reconstructed atmospheric CO₂ during glacial periods from 2580 to 800 ka using pedogenic carbonates in paleosols from the Chinese Loess Plateau.
This is the first continuous early Pleistocene glacial CO₂ record from a terrestrial archive.

Quantifying Earth’s climate sensitivity is critical for projecting future warming. But is sensitivity state-dependent — does it vary between glacial and interglacial periods?
Paleoclimate data offer a deep-time perspective on this question.

50 days' free access:
🔗 authors.elsevier.com/a/1lOtb26gar...

The findings call for a re-evaluation of previous δ¹⁸O-based reconstructions using land snail shells—especially in semi-arid or dew-prone regions.

Want to try it yourself?
The R + JAGS code is open source:
📂 github.com/da-jiawei/la...

This study highlights the importance of thinking beyond rainfall. Dew is isotopically distinct and forms under different conditions.
Snails are active at night—just when dew forms—making them prime dew harvesters. 🌙🐌

To fix this, I modified the classic flux balance model to account for dew formation via the Craig-Gordon model.
The revised model better reproduces observed isotopic values—and yields rainfall-δ¹⁸O predictions consistent with observations.

This is a big deal:
Neglecting dew could lead to systematic underestimation of rainfall δ¹⁸O when back-calculating from snail shell δ¹⁸O.
That’s a potentially serious bias in many paleoclimate reconstructions based on snail shells.

Snail body water δ¹⁸O and δD consistently plot above the local meteoric water line—right where you’d expect dew to plot.
In fact, modeling shows dew can account for up to 50% of the snail’s water intake! 💧🌫️

Using a modern high-resolution dataset from Xi’an, China (Zong et al. 2023), I modeled δ¹⁸O and δD in snail body water with a Bayesian inversion approach.
The key result? The isotopic signature doesn’t match rainfall alone. Something’s missing.

Traditionally, it's assumed that rainfall is the main water source for snails, and therefore the main oxygen source in their aragonite shells.
This assumption underpins shell-δ¹⁸O-based reconstructions of past precipitation. But is it valid? 🤔

The highlights are evidence from the numerical modeling of sensible heat transport and isotope mass balance. 50-day free access: authors.elsevier.com/c/1l8HX52cui...