Jenny McElwain
speaker
162 appearances
1 recordings
1 series
first heard Jul 2026
last heard 2 Jul
Jenny McElwain’s voice in public audio — every appearance, attributed to the second.
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recordings per month · last 12 monthsRecordings per month over the last 12 months — 1 in all, peaking in Jul 2026 with 1.
Appearances
It's a treeless landscape.
It's because it's too cold.
And then you see it in a desert.
In the most extreme deserts, it's too hot.
So I kind of think we can't be complacent.
We know trees, we love trees, but we absolutely can't be complacent.
And we've set up a project in Trinity College Botanic Garden called the Witness Tree Project.
And the idea is that all trees are sensors and they're witnesses of climate change.
And because they're long-lived organisms, you know, many live for thousands of years, most live for hundreds of years or certainly decades.
decades and we are we are tracking 21 trees and it was very difficult to choose which ones and 21 trees every year over time to answer the question you posed which trees are most resilient and we're trying to understand it's called a common garden experiment because we have trees from all over the world growing in the same botanic garden and
So we have trees from the subtropics, trees from cold environments, trees from very warm environments.
And we're trying to understand fundamentally what is it about their traits that enables some to be resilient and others to not withstand a changing climate.
Yeah, so we can, trees are sensors of their environment, so we can actually use them in the fossil record because we have beautiful fossils like that Chris has spoken about.
We have fossil leaves.
We can use those fossils of trees through time to reconstruct how the environment has changed.
So we've been able to reconstruct how the atmosphere has changed in terms of how much carbon dioxide there was in the past, how much oxygen there was in the past.
And also then if you've got greenhouse gases, you can plug that into a climate model, work with your climate colleagues and you can reconstruct how climate has changed through time.
Yeah, so I think that there's a long transition, but the net effect of going from a treeless world to a world of forests and woody organisms and trees is that those trees sequestered, so they pulled carbon out of the atmosphere.
And then many of them, like the lycopods that Chris was talking about, were rather than fungi breaking those trunks down and releasing the carbon back, that carbon was trapped in swamps and peats.
And the net effect over time, millions of years, is that carbon dioxide levels dropped from really high levels, really hot earth to a cool climate.
Showing 81–100 of 162 · page 5 of 9
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