Tree Rings in the High-Latitude Cold Regions of Northeastern China Reveal the Trend of Climate Warming Brought About by the Industrial Revolution Against the Backdrop of the Little Ice Age

Global warming has profoundly affected human socioeconomic development and ecological security. The high-latitude cold regions of China are among the most sensitive areas to global hydroclimatic changes, making it urgent to clarify the long-term climatic evolution in these regions. Based on tree-ring width data from 74 cores of Betula platyphylla collected from the northern slopes of the Greater Khingan Mountains, a 310-year (1715–2024) standardized chronology was established. Using this, the spring mean maximum temperature series for 1733–2024 (292 years) was reconstructed. The reconstructed temperature series shows good consistency with historical climate records, further revealing its evolutionary characteristics. The results show that the historical sequence of the average maximum temperature in spring in the study area has experienced 4 warm periods and 2 cold periods. The warming rate during the Little Ice Age (+0.042 °C/10 a) was significantly higher than that before the Industrial Revolution (+0.026 °C/10 a), indicating that atmospheric circulation anomalies such as AMO and PDO played a dominant role in the natural stage. In the early days of the Industrial Revolution, human activities against the backdrop of the Little Ice Age led to frequent climate fluctuations in this region. After 1958, the continuous intensification of human activities led to a sustained rise in temperature, with the warming rate soaring to +0.046 °C/10a (Cv = 18.7%). The temperature level in the middle of the 18th century was roughly the same as that in the early 21st century. This study reveals the characteristics of climate change in high-latitude cold regions, providing a reference for predicting extreme hot events in spring under the background of global warming.