The heat content of the ocean, along with global-mean surface temperatures of the planet and in the troposphere have shown very little warming since 1998. Is it thanks to more fuel-efficient vehicles? Better environmental laws maybe? Well, researchers at Lawrence Livermore National Laboratory say there’s one factor we’ve overlooked—volcanic eruptions. They say that volcanic activity in the early part of 21st century may have helped to cool the planet by shooting sulfur dioxide gas into the atmosphere, which can form volcanic aerosols. These droplets reflect some of the sunlight back into space, cooling the Earth’s surface and the lower atmosphere.