Juergen Freund / Burner inflating Raging Thunder hot air balloon, Mareeba, Atherton Tablelands, Queensland, Australia

Ashley Cooper / Methane, extracted from an old landfill site on Walney Island, to power a biogas generator producing green electricity, Cumbria, UK, with the Ormonde offshore wind farm in the background. February 201...

Ashley Cooper / Methane, extracted from an old landfill site on Walney Island, to power a biogas generator producing green electricity, Cumbria, UK, with the Ormonde offshore wind farm in the background. February 201...

Ashley Cooper / Methane, extracted from an old landfill site on Walney Island, to power a biogas generator producing green electricity, Cumbria, UK. February 2013.

Ashley Cooper / Staff in the old folks home kitchen cooking using biogas generated in the grounds. Muni Seva Ashram, Goraj, Vadodara, India, December 2013.

Ashley Cooper / Log burner used to heat a house

Ashley Cooper / The Rampside gas terminal in Barrow in Furness, Cumbria, England UK, which processes natural gas from the Morecambe Bay gas fields. February 2013.

Christophe Courteau / Flame of gas cooker in kitchen

Christophe Courteau / Flame of gas cooker in kitchen

Christophe Courteau / Flame of gas cooker in kitchen

Cyril Ruoso / Charcoal burner fungus (Russula cyanoxantha), Alberes Mountains, Pyrenees, France, September.

Orsolya Haarberg / Charcoal burner arranging a pile of burning wood, Calonda, Harghita, Transylvania, Romania, June 2015.