Professor Jim Skea, from the Faculty of Natural Sciences, Centre for Environmental Policy at Imperial College London, joins Jack Stewart in the studio and brings his insight from the Paris climate talks. Paul Younger, the Rankine Chair of Engineering and Professor of Energy Engineering at the University of Glasgow, talks about geothermal energy and its potential as a renewable energy source, particularly in Ethiopia.

Mark Jacobson, Professor of Civil and Environmental Engineering at the University of Stanford, argues for a 100% switch to renewable energy sources.

Tadj Orzesczyn, Professor of Energy and Environment at University College London, talks to us from the perspective of energy demand. If we can reduce this, then we can reduce the amount of energy we need to produce in the first place.

(Photo: Ferrybridge C power station, near Knottingley 2015. Credit: OLI SCARFF/AFP/Getty Images)