 Methane, CH4, is the second most significant contributor to climate change after carbon dioxide, CO2. Satellite measurements show that levels of this gas have increased by around 85 parts per billion over the last 18 years. This represents a 4.8% increase in concentration. The study also showed that the rate of increase has become more pronounced since 2014 when it began to match ground-based measurements. Furthermore, the study revealed that the seasonal cycle of methane in the atmosphere differs between the northern hemisphere's middle and higher latitudes due to the presence of stratospheric methane. This finding provides insight into the global budget of atmospheric composition and the sensitivity of satellite measurements to methane. This article was authored by Li Hongzhou, Jiuying Warner, Nicholas Arnalli, and others.