Study Finds Wyoming Forests Lost 60% Canopy for 100,000 Years During Ancient 6C Warming
Updated
Updated · Fortune · Aug 21
Study Finds Wyoming Forests Lost 60% Canopy for 100,000 Years During Ancient 6C Warming
3 articles · Updated · Fortune · Aug 21
Summary
Science study data from fossil leaf cuticles show southern Wyoming forests lost about 60% of their canopy during the Paleocene-Eocene Thermal Maximum 56 million years ago and stayed thinned for well over 100,000 years.
Thousands of epidermal cell shapes from fossil leaves were matched to modern tropical forest soils, letting researchers reconstruct ancient leaf area index and track canopy density through the warming episode.
Up to 6C of warming initially followed a period of unusually dense forest growth, but heat and drought then overwhelmed any carbon-dioxide fertilization benefit, killing trees and shifting vegetation toward ferns, palms and other warmth-loving plants.
The canopy loss also appears to have reshaped the landscape, with ancient soils giving way to coarser river deposits as altered forests changed water flow, sediment movement and carbon storage.
Researchers say the PETM is the closest natural analog to modern warming, but today’s carbon emissions are rising roughly 10 times faster, raising the risk of crossing forest thresholds with recovery times far beyond human timescales.