On January 11th, ProfessorLi's team conducted a formal assessment of global surface temperatures from1850 to 2023. The assessment indicated that the just-passed year of 2023 hasbecome the warmest year globally. The global mean surface temperature (GMST)has risen by 1.40°C relative to the pre-industrial period (represented by theaverage from 1850-1900), bringing it closer to the 1.5°C warming threshold setby the Paris Agreement. It's worth noting that this warming trend is 0.12°Chigher than the last warmest year (2016) (see Figure 1). In terms of spatialdistribution, the high-latitude regions of the Northern Hemisphere havecontributed the most to the warming trend, with Europe and Central Asia beingthe strongest contributors in the mid-latitude regions (see Figure 2). At thesame time, the global average land surface temperature (GLSAT) and global seasurface temperature (GSST) have both reached their highest levels on record.The GLSAT has warmed by 2.43°C since the onset of industrialization, slightlyhigher (by 0.04°C) than the previous warmest year (2016), while the GSST haswarmed by 0.92°C since industrialization, significantly higher (by 0.15°C) thanthe previous warmest year in 2016. This also reflects the rapid warming trendin the global oceans in recent years.

Based on the China-MST 2.0dataset, the team has, for the first time, reconstructed the 1850-2023 regionalaverage surface air temperature (SAT) series for China using limitedtemperature observations from the 19th century. They have used the latestdeveloped algorithms for observation constraints (Figure 1) and assessed theregional average SAT anomalies in China based on this series. The resultsindicate that the average SAT anomaly in the China region reached 1.50°C in2023 (relative to 1961-1990). If we consider the average SAT anomaly ( -0.88°C)since global industrialization (represented by the 1850-1900 averages), theaverage warming in the China region has reached 2.38°C, which is close to butstill slightly lower than the average warming of GLSAT. Due to the significantdifferences in response and sustainability of greenhouse gas emissions amongdifferent countries/regions (Li et al, 2022), although there are variations inthe warming levels across different regions, future climate change adaptationmust rely on the joint efforts and cooperation of all countries worldwide toprotect and create a better home for humanity.

Figure1. Anomalies series of the global mean surface temperature (GMST), global landsurface temperature (GLSAT), global sea surface temperature (GSST), and Chinatemperature (China SAT) relative to the average value of 1961-1990, from 1850to 2023.

Figure 2. Anomalies of global surface temperature in 2023 (relative to the averagevalue of 1961-1990)

Further reading：

[1]LiZ., Li Q., Chen T., 2023，Recordbreaking high temperature outlook for 2023：An assessment from CMST, Adv. Atmos. Sci., 2024,41:369-376, doi: 10.1007/s00376-023-3200-9

[2]Li,Q., Sheng, B., Huang, J. Li, C., Song, Z., Chao, L., Sun, W., Yang, Y., Jiao,B., Guo, Z., Liao, L., Li, X., Sun, C., Li, W., Huang, B., Dong, W., Jones, P.,2022, Different climate response persistence causes warming trend unevenness atcontinental scales. Nat. Clim. Chang. 12, 343–349.https://doi.org/10.1038/s41558-022-01313-9