Trees Shouldn't Exist

A tree is a giant wooden pole that only exists to lift leaves into the sun, so why are there three trillion of them? In September 2015, Thomas Crowther's team at Yale counted the world's trees from the ground up: 3.04 trillion, almost eight times the old estimate. The reason they exist is an arms race for sunlight that started 386 million years ago, and on the way it may have poisoned the oceans and filled the swamps with giant bugs. In this video: why every tree trunk is a costly weapon, why "tree" isn't really a family, how the first forests may have caused a mass extinction, and why two famous stories about the age of coal and giant insects are probably wrong. 0:00 Trees shouldn't exist 0:42 How do you count 3 trillion trees? 1:58 The deal no forest can keep 3:39 A palm is closer to grass than to an oak 4:48 The oldest forest on Earth 5:52 When trees poisoned the ocean 7:21 The age of giant bugs 8:23 The coal story everyone repeats 9:22 Were the giant bugs about oxygen? 10:09 You live inside the same race 11:02 Look at the trunk Sources: Crowther, T.W. et al., "Mapping tree density at a global scale." Nature (2015). doi:10.1038/nature14967 Koch, G.W. et al., "The limits to tree height." Nature (2004). doi:10.1038/nature02417 Dawkins, R., The Greatest Show on Earth (2009) Boyce, C.K., Fan, Y. & Zwieniecki, M.A., "Did trees grow up to the light, up to the wind, or down to the water?" New Phytologist (2017) Stein, W.E. et al., "Mid-Devonian Archaeopteris roots signal revolutionary change in earliest fossil forests." Current Biology (2019) Smart, M.S., Filippelli, G. et al., "Enhanced terrestrial nutrient release during the Devonian emergence and expansion of forests." GSA Bulletin (2022) Nelsen, M.P. et al., "Delayed fungal evolution did not cause the Paleozoic peak in coal production." PNAS (2016). doi:10.1073/pnas.1517943113 Snelling, E.P. et al., "Oxygen supply through the tracheolar-muscle system does not constrain insect gigantism." Nature (2026). doi:10.1038/s41586-026-10291-3 Wobbleline — big questions about being human, drawn with shaky lines. Narration and illustrations generated with AI tools. Script and research by Wobbleline. #Trees #Prehistory #Science #Wobbleline