No natural history programme can, or should, be made these days without the climate crisis as a looming subtext at the very least. Chris Packham’s confidently grand new series Earth, a guide to “five pivotal moments” in the planet’s history, might look like an exception, since its first episode is set 252 million years ago. But unfathomably distant as that is, it is painfully relevant because of what happened at the close of the Permian period: Earth grew warmer, ending life as it existed then.
A volcanic eruption, a thousand times greater than any ever seen by humans, covered one percent of Earth’s only land mass, Pangea, with liquid fire and released four million cubic kilometres of lava, greenhouse gas and ash. Mass extinction followed: Packham, squatting nimbly by a cliff face, demonstrates it by hammering a lump out of a thin seam of coal, left there when a lot of organic matter died suddenly. Then he chips at the rock above, finding it to be smooth and featureless, a relic of a time when nothing died because not much had survived.
