Two hundred and sixty million years ago, Earth was thriving. The continents were fused into Pangaea, vast glossopteris forests covered the southern hemisphere, gorgonopsians hunted with saber-like teeth, and reefs crowded the shallow seas. Then, in a geological instant, nearly 90% of all marine species and around 70% of land vertebrates were gone. The end-Permian extinction - the Great Dying - is the closest life has ever come to being erased.

The killer was Siberia. For roughly a million years, fissures in the crust poured out between one and four million cubic kilometres of lava. What survives of it still covers two million square kilometres, an area larger than Mexico. As magma forced its way upward it burned through buried coal, venting carbon dioxide, methane, sulfur dioxide and halogen gases straight into the atmosphere. For scale: when Mount Tambora erupted in 1815, it chilled the planet enough that 1816 became known as the Year Without a Summer. Siberia did that for a million years.

Global temperatures climbed by ten to fifteen degrees Celsius - roughly twice the difference between the last ice age and today. Warming oceans lost their oxygen, and bacteria in the anoxic depths filled the water with hydrogen sulfide. Acid rain stripped the forests. The ozone layer thinned. Around the equator, the fossil record simply goes blank.

Trilobites, which had ruled the seas for 270 million years, disappeared for good. Reefs vanished for millions of years. And on a scoured continent, one small dicynodont called Lystrosaurus spread from Africa to Antarctica and dominated an emptied world almost alone.

So what does it actually take to nearly kill a planet? And how did anything survive it at all?

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