In Why CO₂ Is Crucial for Our Planet's Survival, geologist Iain Stewart explains how carbon dioxide is essential for life on Earth. Without enough, planets like Mars are freezing cold, while Venus is scorching hot because it has too much. Early volcanoes released carbon dioxide that helped keep the planet warm enough for life to evolve. Yet, scientists have discovered evidence of a catastrophic "Snowball Earth" event 700 million years ago, where the planet may have been completely frozen, as shown by mysterious drop stones found in Namibia. This video is excerpted from BBC’s Earth: The Power of the Planet, a documentary series in which Dr. Iain Stewart discovers how Earth's forces can shape nature, species, and even the climate.
In Why CO₂ Is Crucial for Our Planet's Survival, geologist Iain Stewart explains how carbon dioxide is essential for life on Earth. Without enough, planets like Mars are freezing cold, while Venus is scorching hot because it has too much. Early volcanoes released carbon dioxide that helped keep the planet warm enough for life to evolve. Yet, scientists have discovered evidence of a catastrophic "Snowball Earth" event 700 million years ago, where the planet may have been completely frozen, as shown by mysterious drop stones found in Namibia. This video is excerpted from BBC’s Earth: The Power of the Planet, a documentary series in which Dr. Iain Stewart discovers how Earth's forces can shape nature, species, and even the climate.