Contents

10 August 2018
Vol 361, Issue 6402

About The Cover

COVER Iguazú Falls, Earth's largest waterfall system, on the Iguazú River between Argentina and Brazil. Earth's turbulent rivers and streams are natural hotspots for atmospheric exchange. Thousands of satellite images have revealed that rivers and streams cover nearly 45% more of the world's surface than previous spatial estimates, indicating that these water bodies contribute more to atmospheric concentrations of greenhouse gas than previously thought. See pages 546 and 585.
Photo: Inge Johnsson/Alamy Stock Photo