Researchers of the Chalmers Technological University in Sweden have unveiled new details about global warming, challenging previous scientific beliefs. A recent study revealed an acceleration of daily warming since the 1990s, contrasting with prior data that indicated more noticeable warming at night. This finding denotes an increased temperature disparity between day and night, potentially exerting a significant impact on life on Earth. The study sheds light on the evolving dynamics of global warming.
The previous consensus held that night temperatures were rising at a faster rate than daytime temperatures. However, the latest data covering the period from 1961 to 2020 reveals a contrary trend: an acceleration of warming during the day alongside relatively stable nighttime temperature growth. Scientists have labeled this phenomenon “reverse asymmetric warming.”
Zzyan Zhong, a postdoctoral researcher from Chalmers, expressed surprise upon discovering that the longstanding trend of asymmetric warming has reversed over the past three decades. One possible explanation for this shift is the notion of “global enlightenment,” which pertains to a reduction in cloud cover resulting in a greater amount of sunlight penetrating the Earth’s surface.
This change in warming dynamics may also be linked to an increase in regional droughts and heatwaves, consequently weakening the cooling effect of evaporation. Researchers found that while night warming predominated on most land areas from 1961 to 1990, the situation changed between 1991 and 2020, with 70% of the observed territories experiencing heightened warming during daylight hours.
These alterations can have implications for agriculture, human and animal health, as well as plant growth. For instance, an increased temperature difference between day and night can lead to more frequent heart contractions and higher blood pressure, thereby increasing strain on the heart and potentially raising mortality and morbidity rates. The impact of this reverse trend on tree growth and the carbon cycle will be the focus of future investigations.