Geologist Iain Stewart fronted this three-part BBC Two series, broadcast over consecutive Tuesdays in February 2012, that reframed botany as planetary engineering. Each 59-minute instalment travelled from primordial fossils to living laboratories, arguing that photosynthesisers terraformed the planet long before humans arrived.
Episode one, “Life from Light”, opened in a 3-billion-year-old South African sandstone quarry where cyanobacteria first pumped oxygen into the air. Stewart then scuba-dived in a Mexican sinkhole to measure how modern algae still shift the chemistry of oceans and skies. The programme calculated that today’s plants exhale 80 billion tonnes of oxygen annually, a figure converted into the equivalent of 7 trillion party balloons to make the scale intuitive.
“The Power of Flowers” moved from prehistoric Arctic forests to a Kew Gardens hothouse, tracking how flowering plants accelerated evolution by trading colour, scent and nectar for mobility. Thermal cameras caught a voodoo lily raising its own temperature to attract pollinators, while time-lapse revealed wheat roots secreting acid to dissolve rock and mine phosphates. Stewart’s thesis: angiosperms didn’t just colonise land, they quickened geological weathering and dragged carbon from the air, sculpting the soils on which agriculture later depended.
Final episode “The Challenger” examined grasses, the plant dynasty that shaped human destiny. In Ethiopia’s Rift Valley, Stewart chewed raw teff with local farmers whose ancestors domesticated the cereal 6 000 years ago, then demonstrated how silica-rich blades grind down mammalian teeth faster than granite. The series concluded that civilisation itself is a side-effect of grass evolution, a claim backed by carbon-isotope analysis of ancient soil showing the global spread of prairies coincided with the rise of settled societies.
Production Details
BBC Two / 1 Season / 3 Episodes / 2012
Producer(s): Andrew Thompson (series producer)
Cinematography: Neville Kidd
Main Cast
Iain Stewart as Himself - Presenter
