Text: Nada Salsabila
Photo: NASA
The bad news about Earth comes from research that has been done over the last two decades. The research revealed that the Earth lost its luster. The most likely cause of this is climate change which can exacerbate the effects of global warming in the future. First published in the journal Geophysical Research Letters, the study tracked planetary light between 1998 and 2017 by combining data about 1,500 nights collected at Southern California’s Big Bear Solar Observatory.
This research was also achieved by observing a phenomenon called “earthshine”, which is light reflected by the Earth on the dark side of the moon that gives off a pale glow in the darker night sky. These “earthshine” measurements are also combined with data on solar brightness and satellite analysis of Earth’s reflectivity (albedo) from NASA’s Clouds and Earth’s Radiant Energy System (CERES) projects. From these findings, it was concluded that Earth’s brightness has dimmed by about half a percent since the 90s. Most of the decline occurred in the last three years leading up to 2017 (where the analysis ends), and was followed by sharper declines during 2018 and 2019.
While 0.5 percent may not sound like much, Philip Goode, a New Jersey Institute of Technology astronomer and lead author of the study, said the drop in albedo came as a surprise to them when analyzing the last three years of data after 17 years of nearly flat albedo. Then the research team concluded that changes in the sun’s brightness had no correlation with Earth’s dimming, meaning that something inside Earth must have changed. This could be a reduction in lowland clouds in the Eastern Pacific, where sea surface temperatures are rising sharply. These changes also have a possible connection to the climate crisis.
Edward Schwieterman, a planetary scientist at the University of California at Riverside, said that this is quite worrying and suggests the opposite of previous research. Scientists previously predicted that a warmer planet could cause more clouds, meaning more of the sun’s heat would be reflected off and less trapped by greenhouse gases. Basically, the literal dark conclusion is that the dimming of the Earth could actually make the global warming effect happen more quickly, which will also impact the future of Earth’s climate.
–
