Meet Africa's first heat officer! Eugenia Kargbo is taking action to make Freetown a tree town and bring down rising temperatures. She will be working with MEER to implement solar reflectors in her city of Freetown.

What geoengineering is worth trying? Dr Ye Tao and Prof Jem Bendell discuss

Rachel Donald discusses the Planet: Critical episode with Ye Tao on Buying Time With Geoengineering