A group of scientists who have climbed 5 of the world’s 8 tallest trees have examined their physiology in detail and have concluded that trees probably cannot grow more than 130m or 426ft. The tallest trees in the world are Coastal Redwoods in California and Oregon, and they consume a ridiculous amount of water.
When they examined the specimens' water flow, leaf structure and density, photosynthesis capability and carbon dioxide concentration, all appeared to converge at their minimum levels of efficiency at the heights reached by the Humboldt redwoods. For that reason, they may not exceed more than 130m. They’ll be monitoring them in the future.