The year 2016 is the hottest year on the world record. The surface temperature is 1.1℃ above those of the preindustrial with the major greenhouse gas concentrations continuing to rise. Under the impact of global warming, Arctic sea ice remained at very low levels and there was significant melting of continental ice on Greenland and Antarctic. Warming also affected the oceans, resulting in global sea level rising and the changes of marine environment. Droughts continued into early 2016, causing food and water crisis in numerous parts of the world. Various kinds of extreme climate events occurred frequently and caused serious social and economic losses worldwide. This paper summarizes the major events and the impact in 2016, and analyses the main causes of typical events including the flood disasters in the Yangtze River Basin in China and the heat wave during summer in the United States. Analysis shows that the westward extension and enhancement of West Pacific subtropical high led to the transport of warm and moist air flows from low latitude to the Yangtze River Basin, while the upper trough in Northeastern Asia brought the cold air southward. The interaction of the warm and cold air masses led to the extremely heavy rainfalls and severe floods in China. The stagnation and stability of North America subtropical high and the weakening condition of water vapor transport are the main cause for the summer heat wave in the United States.