Science Snippets: The Sky is Falling (I’m No "Chicken Little")

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Almost every day, I’m accused of being Chicken Little. I’m surprised, if only because most people alive today have no memory of Chicken Little. Chicken Little is for people my age, plus or minus a few years. For people watching this video significantly younger than me, Chicken Little said the sky was falling. This was the chicken’s version of a calamity about to occur.

According to a 18 May 2023 article at YaleEnvironment360, “the sky is falling—literally.” The article is titled The Upper Atmosphere Is Cooling, Prompting New Climate Concerns. Here’s the subhead: “A new study reaffirming that global climate change is human-made also found the upper atmosphere is cooling dramatically because of rising CO₂ levels. Scientists are worried about how this cooling could affect orbiting satellites, the ozone layer, and Earth’s weather.” As most people know, cool air descends. Thus, the quote about the sky falling.

This article in YaleEnvironment360 indicates that much of the research focused on changes in the atmosphere has been done by scientists at NASA, the National Aeronautics and Space Administration of the United States. NASA is interested in the aforementioned satellites, as well as the ozone layer and the weather here on the surface of Earth. And, of course, many scientists at NASA are interested in anthropogenic climate change. These scientists, and others, previously referred to the upper layers of the atmosphere as the ignorosphere because so little is known about these upper layers. As a result, we have been ignorant about the upper atmosphere. Hence, ignorosphere. With a recent peer-reviewed article mentioned in the YaleEnvironment360, paper, we know more. As with most of the information we report in this space, adding to the accumulated data points to ever-worsening news, whether or not Chicken Little is involved.

The paper at YaleEnvironment360 points to an article in the renowned, peer-reviewed journal, Proceedings of the National Academy of Sciences. The peer-reviewed paper was published on 8 May 2023 and titled, Exceptional stratospheric contribution to human fingerprints on atmospheric temperature. It was written by Benjamin D. Santer and 8 other scholars.

From the Significance section of the peer-reviewed paper comes this information: “Differences between tropospheric and lower stratospheric temperature trends have long been recognized as a ‘fingerprint’ of human effects on climate. This fingerprint, however, neglected information from the mid to upper stratosphere, 25 to 50 km above the Earth’s surface. Including this information improves the detectability of a human fingerprint by a factor of five. Enhanced detectability occurs because the mid to upper stratosphere has a large cooling signal from human-caused CO₂ increases, small noise levels of natural internal variability, and differing signal and noise patterns. Extending fingerprinting to the upper stratosphere with long temperature records and improved climate models means that it is now virtually impossible for natural causes to explain satellite-measured trends in the thermal structure of the Earth’s atmosphere.” In other words, not surprisingly, there is such as thing as anthropogenic climate change. In fact, the Abstract of this peer-reviewed paper concludes with this line: “Our results explain … incontrovertible evidence of human effects on the thermal structure of Earth’s atmosphere.”

Early climate modelers predicted that the combination of tropospheric warming and significant cooling higher in the atmosphere resulted from increased atmospheric carbon dioxide. The detailed confirmation of this prediction from more than 50 years ago greatly improves our confidence in understanding the relationship between carbon dioxide and atmospheric temperatures. In response to this renewed understanding, the lead author of the peer-reviewed paper in the Proceedings of the National Academy of Sciences said, “these results make me very worried.”

The contraction of the upper atmosphere is making it thinner, which reduces drag on satellites and other objects in orbit. The abundance of space junk is increasing the likelihood of collisions. This, however, is the least of our problems. The much more significant problem associated with stratospheric cooling is the impact on atmospheric ozone.

As most of us know, the fragile condition of the ozone layer is already a cause for concern. Under assault from chlorofluorocarbons, ozone holes are already forming around the globe, as we have reported in this space. The 1987 Montreal Protocol designed to solve this problem addressed the emission of chlorofluorocarbons. It did not, and cannot, deal with stratospheric cooling. The ozone layer over Antarctica has been slowly reforming since the implementation of the Montreal Protocol, but the planetary air conditioner known as the Arctic is still losing atmospheric ozone. The first full-blown ozone hole formed over the Arctic in 2020. As indicated by a 23 June 2021 paper in the peer-reviewed, open-access Nature Communications, this situation is certain to worsen as greenhouse gases continue to be emitted.