Climate change is a key challenge to the existence and development of humankind. Starting from searching for the roots of greenhouse gas emissions，this paper puts forward the development idea of promoting world energy transition and combatting climate change by establishing Global Energy Interconnection（GEI）. It analyzes the significance and feasibility of speeding up the construction of GEI，as well as the vital function of GEI in tackling climate change，introduces concrete practices and results of GEI development in China and the rest of the world，and identifies key tasks of pushing forward the construction of GEI. All in all，to establish GEI will help tackle global challenges including climate change and achieve sustainable development of humankind.