The article discusses the paradox of climate change where, despite surface and lower atmospheric warming, the upper atmosphere (stratosphere) is cooling. This phenomenon has been observed for decades and is believed to be a clear indicator of human-induced climate change, though the mechanisms behind it were not fully understood until recently.
A study from Columbia University’s Lamont-Doherty Earth Observatory, led by Sean Cohen, sheds light on this cooling effect caused by CO2. In the lower atmosphere, CO2 traps heat, warming the surface. However, in the stratosphere, CO2 behaves differently, acting like a radiator by absorbing and emitting infrared energy, leading to cooling as CO2 concentrations rise.
The researchers developed a quantitative theory to explain stratospheric cooling, identifying key processes that influence how CO2 interacts with different infrared wavelengths. They found a specific range of wavelengths that are particularly effective in promoting cooling. As CO2 levels increase, this effective range expands, reinforcing the cooling effect.
The study emphasizes that while CO2 cools the stratosphere, it also reduces the amount of heat radiated into space, contributing to surface warming. Furthermore, understanding this cooling mechanism not only informs climate science on Earth but may also enhance our knowledge of atmospheric processes on other planets.
In summary, the research provides a clearer understanding of the mechanisms driving stratospheric cooling and their implications for climate models and predictions.
Source link
