Joanna Haigh, Professor of Atmospheric Physics at Imperial College, London, studies the influence of the sun on the Earth's climate using data collected by satellites. She talks to Jim al-Khalili about how she got started on her career in climate physics: she can trace her interest in it back to her childhood when she built herself a home weather station.

Jo Haigh explains why we need to know how the sun affects the climate: it's so scientists can work out what contribution to warming is the result of greenhouse gases that humans produce, and what is down to changes in the energy coming from the sun.

She has sat on the Intergovernmental Panel on Climate Change and discusses with Jim how it delivers its reports. And as a prominent scientist who speaks out about the dangers of increasing man made greenhouse gases in the atmosphere, she explains how she responds to climate change deniers.