AGU NEWS: NORTHERN HEMISPHERE SUMMERS MAY LAST NEARLY HALF THE YEAR BY 2100

AGU NEWS

NORTHERN HEMISPHERE SUMMERS MAY LAST NEARLY HALF THE YEAR BY 2100

Academic Article

Wang, J., Guan, Y., Wu, L., Guan, X., Cai, W., Huang, J., et al. (2021). Changing lengths of the four seasons by global warming. Geophysical Research Letters, 48, e2020GL091753. https://doi.org/10.1029/2020GL091753

Plain Language Summary: A series of phenomena such as early flowering of plants and early migratory birds are suggesting that the traditional four seasons may have changed. We focus on how the four seasons changed during 1952–2011 and will change by the end of this century in the warming Northern Hemisphere midlatitudes. We find that lengths and start dates of the four seasons have changed, and the changes will be amplified in the future. Over the period of 1952–2011, the length of summer increased from 78 to 95 days and that of spring, autumn and winter decreased from 124 to 115, 87 to 82, and 76 to 73 days, respectively. In addition, summer is projected to last nearly half a year, but winter less than 2 months by 2100. Such changes can trigger a chain of reactions in agriculture, policy-making for agricultural management and disaster prevention requires adjustment accordingly. The seasonal-related topics involving ecology, the ocean and the atmosphere also need to be revisited.