I am an atmospheric scientist who researches climate change. I am interested in how much global warming we should expect from increasing greenhouse gases. This inevitably leads to the study of clouds, which cool the planet by reflecting sunlight back to space and warm the planet by reducing the infrared radiation emitted to space. How the balance of these competing effects changes as the planet warms (known collectively as the ‘cloud feedback’) largely determines how much warming accompanies increasing greenhouse gases. I use theory, observations, and global climate models to investigate these challenging questions.