A new but unbelievable climate proxy – plant leaf wax
From the UNIVERSITY OF BIRMINGHAM and the “thinnest of evidence” department comes this claim.
Fossilised plant leaf wax provides new tool for understanding ancient climates
New research, published in Scientific Reports, has outlined a new methodology for estimating ancient atmospheric water content based on fossil plant leaf waxes.
As the Earth’s surface and atmosphere warm, the amount of moisture – water vapour – in the atmosphere will increase. Understanding the size of this increase is important for predicting future climates as water vapour is a significant greenhouse gas. Atmospheric moisture content also influences the patterns and intensity of rainfall events.
The relationship between temperature and moisture content can be explored by the study of intervals in Earth’s history when climates where significantly warmer than those seen in modern times, which necessitates a method for estimating ancient atmospheric moisture content.
Dr Yvette Eley, from the University of Birmingham, explained,
“If we want to understand how the Earth would work with a climate substantially warmer than today, we have to study intervals millions of years in the past – made difficult because these warm climates are much older than our oldest climate records from Antarctic ice cores (less than one million years old).”
To try and understand climate properties related to the atmosphere – like rainfall and atmospheric moisture content – in such ancient times is very challenging. Existing methods, using calcium carbonate concretions that form in soils, or the chemistry of fossilised mammal teeth, are both hampered by their relative rarity in ancient sediments.
Dr Eley added,
“Our new approach to quantifying ancient atmospheric moisture content relies on the fundamental properties of plant leaves, and how they alter their protective waxy coverings in response to water stress. These leaf waxes are tough and resistant, and are regularly found as what we call biomarker compounds in ancient river, lake and even marine sediments.”
A method of estimating ancient moisture content based on these plant wax compounds overcomes the limitations of other methods because plant waxes are commonly found in soils and sediments stretching back tens or even hundreds of…
