“Koala climbing tree” by Diliff – Own work. Licensed under CC BY-SA 3.0 via Commons.

Guest essay by Eric Worrall

A professor has received a $5 million grant, to investigate whether rising CO2 and predicted endless drought will make the Koala’s Eucalyptus leaf diet too toxic for them to eat.

… The koala could soon be even more endangered than at present, if it turns out that climate change alters the nutritional value of the only food it can eat—Eucalypt leaves. Assistant Professor Elizabeth Neilson from the Department of Plant and Environmental Sciences from University of Copenhagen has received a $5 million grant from the Villum Young Investigator Program for the search of how the chemical structure of the leaves is disrupted.

“We are going to investigate how two distinct results of climate change, drought and elevated CO2 levels, affect the balance between nutrient and toxicant content of the Eucalypt leaves and how this affects the Koala. Eucalypt leaves are highly toxic and the koala needs to sleep or rest for 20 hours a day to efficiently detoxify the poisonous components and gain sufficient energy from their diet. Therefore, the huge amount of energy spent on detoxification is only just about made up by the nutritional value. Any shift in the eucalypt chemistry caused by climate changes may alter the balance of nutritional value and toxicity, and impact koala survival,” says Assistant Professor Elizabeth Neilson.

She and a group of colleagues founded the idea behind the project back in 2012 and she has been working in the lab and in the field almost ever since. …

Read more: http://phys.org/news/2016-02-climate-koalas-diet-inedible.html

I’ve got to admit, I’d be working in the field as well, if someone gave me a $5 million grant.

But it seems deeply implausible that the Koala will be affected by any climate change we’re likely to cause. Koalas have been around for at least 20 – 30 million years, during which Australia has seen radical changes in climate, swinging from rainforest to desert. The ancestors of Koalas had a much more varied diet, but were forced to specialise when the continent dried out, during the brutal dive into the current Quaternary glaciation.

There are issues which threaten the species, such as the raging Chlamydia epidemic which is threatening to destroy wild populations. I doubt very much that climate is anywhere near as serious an issue, as the threat posed by sexually transmitted disease. A return to a warm, wet climate, as prevailed before our current cold period, would not be a threat to a species which has endured far worse.