United States: Talking about the year 2023 and 2024, global temperatures reached record highs, averaging about 1.5°Celsius which is almost above pre-industrial levels. This is really very much higher than climate models had predicted. While climate change and the El Niño weather pattern are partly responsible, neither alone explains the unusually warm temperatures. Changes in cloud cover may also play a big role in these temperature increases.
Now, researchers think the answer is just the opposite: low levels of clouds decrease in 2023. This transition also lowered the albedo in the Earth – capacity to reflect solar energy back to space and thereby perceived an increase in temperatures.
Finally, Earth’s albedo has been decreasing over the past 50 years largely, albeit indirectly, as a consequence of global warming, as the reflective polar ice caps continue to melt. However, in a study using mathematical analysis of satellite data, Helge Goessling of the Alfred Wegener Institute, Germany, and his colleagues identified that the planetary albedo reached a record low in 2023.
As reported by Newscientist, Goessling and his colleagues then used both climatologic observations and simulations to investigate the causes for this drop and realized that there had been a significant decrease of low clouds on the surface in 2023. The change was most significant in the Atlantic Ocean where some of the most probable temperature shifts in 2023 were noted.
“We were also able to identify at least this indication of where the clouds are actually forming, at which altitude to the atmosphere,” Goessling concludes. “It really is quite striking that this, this decrease of the cloud cover, is mostly happening at the lower levels.”
The result may help to explain the extra 0.2 degrees Celsius of missing heat that scientists had tried to trace beyond background climate change and the 2023 El Niño event. “It is another addition to these findings, and Goessling believes it is rather essential.
Although the study only considered data up to 2023, the result could also account for why global temperatures have stayed so high throughout the year 2024 even after El Niño disappeared early this year.
Paulo Ceppi teaching at Imperial College London said that the study is useful in the respect that climate scientists are eager to know reasons behind the recent record heat. “