Editor’s Note: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing our planet, together with the solutions. Rolex’s Perpetual Planet initiative has ...

(CNN) — In the race for alternative, sustainable jet fuels, some companies are getting creative. We’ve heard about planes powered with cooking oil, but what about jet fuel made entirely from human ...

Sewage is an interesting potential solution and is not one to be sniffed at, says Hewitt. But she cautions that, as with all SAF, it will still produce the same amount of carbon emissions when the ...

(CNN) — In the race for alternative, sustainable jet fuels, some companies are getting creative. We’ve heard about planes powered with cooking oil, but what about jet fuel made entirely from human ...