A recent study conducted by researchers from Chalmers and the University of Gothenburg, among others, has revealed a shift in what scientists already knew about global warming dynamics.
The study points out that with greater daytime warming taking place since the 1990s, the temperature difference between day and night is widening, potentially affecting all life on Earth.
The research, published in Nature Communications, reinvestigated the asymmetric warming phenomenon and found that the pattern has reversed.
Between 1961 and 2020, global daytime warming has accelerated, while the warming rate of nighttime temperature is relatively constant. This reversed trend in asymmetric warming has led to an increasing temperature difference between day and night.
The researchers suggest that the larger temperature difference between day and night could potentially affect crop yields, plant growth, animal well-being, and human health.
For example, an increased temperature difference between daytime and nighttime is recognized as one of the environmental stressors that could lead to elevated heart rate and blood pressure, consequently increasing cardiac workload and the mortality and morbidity of cardiovascular and respiratory diseases.
The researchers found that the majority of land, 81 percent of the total area, experienced larger nighttime warming from 1961 to 1990.
However, a shift occurred in the subsequent period from 1991 to 2020, with 70 percent of the observed land areas experiencing larger daytime warming instead.
The study also indicates the need to adjust strategies in different areas affected by temperature variations between day and night, such as agriculture, public health, and forestry management, to address the challenges posed by climate change.
The researchers suggest that further research is needed to investigate the impacts of this reversed trend in asymmetric warming on tree growth and the carbon cycle.
Journal Reference
- Zhong, Z., He, B., Chen, H. W., Chen, D., Zhou, T., Dong, W., Xiao, C., Xie, S., Song, X., Guo, L., Ding, R., Zhang, L., Huang, L., Yuan, W., Hao, X., Ji, D., & Zhao, X. (2023). Reversed asymmetric warming of sub-diurnal temperature over land during recent decades. Nature Communications, 14(1), 1-10. DOI: 10.1038/s41467-023-43007-6