It’s easy to look up how much rain fell in Boston in 2018, 2000, or even 1920. But how do we figure out how rainfall was different 1,000 or more years ago — and what does that have to do with modern climate change? In this talk, Christine Y. Chen and Gabi Serrato Marks, two geoscientists at MIT, discuss their research studying ancient lakes and caves in exciting, far-flung places like the high-altitude central Andes and northeast Mexico. They describe their search for ancient stalagmites, relict shorelines, and fossilized algae that serve as natural archives of Earth’s changing climate and rainfall, and take the opportunity to hold specimens of these geologic “log books” of past rainfall yourself! Join on a trip back in time to explore the dramatic changes in water availability around the world and what it may mean for our future.