Stars' orbits are analyzed, and the changes of global temperature, water vapor, carbon dioxide, and vegetation are analyzed. The results show that the earth's temperature is mainly determined by the earth' s orbital location in the solar system, and carbon dioxide for temperature change is just a disturbance or a fine-tuning role. The space-time variation of the meteorological (weather) and ecological system is the main regulation form when celestial bodies are moving, and the spatiotemporal distribution of the ecosystem is greatly influenced by the temporal and spatial distribution of atmospheric water vapor (rainfall),which is also determined by orbital positions of celestial bodies on a large scale. Temporal and spatial variation of water vapor content, rainfall and vegetation adjust the greenhouse effect of carbon dioxide,and vegetation adjusts the temperature through absorption and emission of carbon dioxide. The global change research should be divided into two levels: the one taking the earth system as the core of the system,and the other focusing on the extra-system research which considers other planetary orbital changes,the changes of Earth's gravitational field and magnetic field,and solar radiation changes. A model for global climate-ecosystem's changes is proposed based on Kepler's law-universal gravitation law and general relativity, which is of great significance to forecast of spatial climate change,natural disasters and ecological system's spatial evalution.