The Earth is warming and its climate is changing. Indeed, measurements show that the Earth has warmed by 0.74ºC over the last 100 years. Warmer surface temperatures heat the oceans, melt ice sheets, and alter weather patterns across the globe.There are cascading effects of climate change, with some areas becoming drier due to more heat and evaporation, such as the Sahel, the Mediterranean basin, Southern Africa, and parts of Southern Asia. Other areas are experiencing increased and more variable precipitation, particularly the east of North and South America, Northern Europe, and Northern and Central Asia. Over the past 50 years, weather patterns have also become more variable.