The maximum likelihood climate change for global warming under the influence of greenhouse effect and Lévy noise
Yayun Zheng, Fang Yang, Jinqiao Duan, Xu Sun, Ling Fu, Jürgen Kurths
Abstract
An abrupt climatic transition could be triggered by a single extreme event, and an α-stable non-Gaussian Lévy noise is regarded as a type of noise to generate such extreme events. In contrast with the classic Gaussian noise, a comprehensive approach of the most probable transition path for systems under α-stable Lévy noise is still lacking. We develop here a probabilistic framework, based on the nonlocal Fokker-Planck equation, to investigate the maximum likelihood climate change for an energy balance system under the influence of greenhouse effect and Lévy fluctuations. We find that a period of the cold climate state can be interrupted by a sharp shift to the warmer one due to larger noise jumps with low frequency. Additionally, the climate change for warming 1.5°C under an enhanced greenhouse effect generates a steplike growth process. These results provide important insights into the underlying mechanisms of abrupt climate transitions triggered by a Lévy process.