Climate change: the elephant in the room

Understanding the true extent of the impact of climate change is like pushing over a row of dominoes. Once you push the first one, a series of hidden consequences is exposed, which are all connected to each other.  Each domino that falls makes everything increasingly more complex.

The effects of climate change might seem pretty obvious—global warming causes rising sea levels and erratic weather patterns cause increasing numbers of natural disasters etc—but the impact goes much deeper than that. If we take the example of how it impacts just one species—African elephants—we’ll see there are a lot more dominoes falling over than you might realise.

Let’s tip the first domino.

Photo by Rachael Lowe

African elephants (Loxodonta africana) are a vulnerable species. They have been experiencing a rapid population decline as a result of human activity, both in illegal trade and in habitat destruction, and now, thanks to climate change, they also face the ongoing battle of drought alongside all of southern Africa.

Elephants are pachyderms, an order of mammals that don’t have sweat glands. As warm-blooded, endothermic organisms, mammals must maintain a steady body temperature (homeostasis) of around 36 to 38 degrees Celsius. The cost of not offloading this heat is, in the short term, overheating and, in the long term, permanent cell damage and deformity. Most mammals can sweat to offload this heat, but what do you do if you have seven tonnes of mass coupled with thick, impermeable skin? Some means of cooling down are innate, and some are behavioural. Innate processes include drinking, passing faeces and urine, and emitting short-wave and long-wave radiation into the environment. Behavioural processes include flapping their ears and spraying their body with mud like sunscreen. Most importantly, they also seek shade and roll and splash in water. But how does this tie in with climate change?

Let’s watch the next domino tip over.

Because climate change-induced drought has ravaged the ecosystems of South Africa for well over a decade now, the landscape is dry and seasonal rains are a rarity. So the equation we have is: hot elephants getting hotter, plus reduced access to water that they heavily rely on to engage trans-epidermal cooling (mock sweating). What can they do? The best thing they can do to keep cool is to seek shade. Where’s the best shade? In a forest. The top layer of trees, called a canopy, insulates the cool air underneath. So, elephants seek canopied forests, which are a reasonably rare sight in South Africa. Elephants do naturally occur in these ecosystems, but they have established paths that they follow. Unfortunately, elephants are spending more time there seeking shade and creating new corridors. The forests are very delicate ecosystems and do not respond well to modification.

So the next domino tumbles.  

Elephants also bring in a lot of foreign species to these ecosystems. In their dung, they bring in the seeds of savannah grasses and bushes that are dominant over most forest species. And, if an elephant can fit in the forest, so now can other large animals through the same corridors. These animals are grazers and browsers which mean they will eat the vegetation from head height down. This is the core of the forest ecosystem, and where many highly endangered species live.

An elephant exclusion zone in a forest that is accessed exclusively by mesoherbivores. Photo: Rachael Lowe

The equation is now: drought, plus hot elephants, plus cool forests equals a slowly collapsing endangered forest ecosystem. Can it get worse? Unfortunately, it can.

The next domino falls.

There are two main solutions to this problem, both of which come at a heavy cost. Almost all elephants and forests in South Africa are protected within fenced game reserves. So the immediate solution to this would be to introduce more artificial water sources to these reserves, right? Unfortunately elephants have what is called a radius of inhabitancy damage. Around any water source, elephants have a destructive impact on a ten kilometre radius around that water source, which, in a small reserve, would do irreparable ecological damage. Putting in artificial water sources is also expensive and not a high priority in a drought-ravaged society.

The other solution is to open the fences of reserves to northern countries that receive seasonal, tropical rainfall. But, the fences were put in to stop poachers, people who kill animals for their parts, such as ivory. Opening the fences impedes the anti-poaching and illegal wildlife trade defences and politically, is not an option.

Our dominoes have fallen to expose a distressing outlook for elephants and for endangered ecosystems. The next step is to continue research to inform management practices and encourage trans-frontier fenced game reserves, such as the Kgalagadi National Park. More importantly, it is time to raise awareness of the problem before it becomes irreversible as so many of the other impacts of climate change have become.

It's time to address the elephant in the room. 

 

Main photo: Diana Robinson on Flickr