Recent research by Lawrence Livermore National Laboratory (LLNL) scientists has demonstrated that human activities are significantly altering the thermal structure of Earth’s atmosphere. By extending climate “fingerprinting” methods to include the mid-to-upper stratosphere (25-50 km above the surface), the researchers improved the detection of human impacts on climate by five times. Notably, this new analysis highlights that it is nearly impossible for natural factors to account for observed satellite-measured changes in atmospheric temperature.
The study reveals distinct CO2-driven temperature patterns in the upper stratosphere, where the influence of human-induced climate change is more pronounced than natural variability. Previous studies focused primarily on the tropospheric layer, neglecting the clearer signals present in the stratosphere. The researchers assert that the stratospheric cooling caused by CO2 emissions is increasing with altitude, contrasting with more limited natural variations.
This finding was reinforced by improved satellite data sets and climate models, bringing together insights from various institutions including UCLA and NOAA. The work underscores the necessity of considering the mid-to-upper stratosphere in future climate assessments. The study was funded by the Department of Energy and published in the Proceedings of the National Academy of Sciences.
