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The Late Paleozoic Ice Age (LPIA) was the longest-lasting icehouse in the Phanerozoic. Previous studies indicated a climate warming interval in the earliest Permian—an apex of the LPIA. To better understand hydroclimatic changes and carbon cycling within this time interval, we conducted a series of high-resolution geochemical and rock magnetic analyses, including magnetic measurements (e.g., magnetic susceptibility, anhysteretic remanent magnetization, hysteresis loops, temperature-dependent susceptibility), ratio of iron to potassium (Fe/K), and carbonate carbon isotope (δ13C carb) from a deep-marine section in South China. Calibrated to the published astronomical time scale, a negative δ13C carb excursion (−1‰) was identified during 298.4–297.9 Ma, and it was time-equivalent with the warming interval, recognized by a decrease in conodont apatite oxygen isotopes in South China, low-latitude sea-level transgression, and high-latitude deglaciation. The negative δ13C carb excursion also coincided with a magmatic pulse of the Skagerrak-Centered Large Igneous Province (LIP), indicating that the perturbation in carbon cycling is likely associated with the release of volcanic CO 2. Furthermore, cyclostratigraphic analysis on multiple paleoclimatic proxies, including ferrimagnetic susceptibility, gamma-ray, and Fe/K, suggested that the negative excursion of δ13C carb also overlapped with the maximum of the eccentricity cycle. It implied that orbital configurations may amplify the feedback of the LIP, causing this short-term warming interval. • High-resolution carbon isotope and magnetic record in the earliest Permian. • Transient climate warming interval is documented in the earliest Permian. • LIP and orbital forcing were critical drivers of the earliest Permian warming. [ABSTRACT FROM AUTHOR]

• The Tuva–Mongol and Amuria blocks were at low latitudes during 330-315 Ma. • The Boreal Realm likely extended into equatorial regions at 330 Ma. • The Boreal Realm developed in a wide northern temperate zone during 330-315 Ma. Fossil organisms of the Boreal Realm in the Tuva–Mongol Block (TMB) and Amuria Block (AMB) are commonly thought to have lived at mid to high latitudes during the Carboniferous Period; however, reliable paleomagnetic constraints have not been available previously to test this hypothesis. Here we report newly obtained combined paleomagnetic and geochronological results from the Upper Mississippian Gunbayan Formation in the AMB and the Lower Pennsylvanian Altan-Ovoo Formation in the TMB. Zircon U–Pb dating of tuff beds from the Gunbayan and Altan-Ovoo formations yield ages of 331.0 ± 2.7 and 315.5 ± 2.4 Ma, respectively. A total of 263 paleomagnetic specimens underwent stepwise thermal demagnetization. After removing the viscous remanent magnetizations of the recent geomagnetic field, stable high-temperature components (HTCs), carried by magnetite, were successfully acquired from 240 specimens. The HTCs of the Gunbayan Formation passed a fold test and a reversal test, and those of the Altan-Ovoo Formation passed a fold test, suggesting that they represent primary remanence magnetizations. We used the elongation/inclination method to test and correct for all the HTC directions of the clastic rocks of the studied formations. Their corresponding paleomagnetic poles are 46.0°N/320.0°E (A = 95 2.0 °) at ca. 330 Ma for the AMB and 43.5°N/355.9°E (A = 95 2.9 °) at ca. 315 Ma for the TMB. The updated paleomagnetic database indicates with certainty that both the TMB and the AMB were located in northern hemisphere low-latitude regions and close to the equator at ca. 330 Ma, suggesting that the Boreal Realm might have extended into the equatorial region at the onset of the large ice age of the Carboniferous. The paleobiogeographic characteristics and distribution of climate-sensitive lithologies indicate that this realm occupied a wide northern temperate belt during 330–315 Ma. [ABSTRACT FROM AUTHOR]