As shown on the History Channel. In the remote wastes of Siberia buried under snow are the remains of one of the greatest catastrophes that the Earth has endured. 250 million years ago, huge volumes of lava spewed out onto the surface--so much that it would have buried the whole of Texas under one mile of lava. At first the temperature dipped but then the greenhouse gases that escaped from the depressurized lava caused a massive global warming. It wreaked havoc, and 95% of the species on Earth became extinct. Yet life hung on and in time this disaster paved the way for the next phase of life on earth--the age of the dinosaurs.