Remember the 2020 mass death of African elephants? The killer is climate change

It was Botswana that rose to the centre of world attention in June 2020 because of a disaster of staggering proportions that had struck its elephants.
More than 350 animals had died in wholly mysterious circumstances in the Okavango Delta. The photos had gone around the world, arousing horror and dismay not only among animal rights activists, but among all those with even a minimal awareness of the common fate of humans and animals on this planet.

The animals, of all ages, had been seen walking laboriously in circles before collapsing to the ground and dying. A sight as shocking as any: according to ethologists, it was the largest die-off of elephants whose cause appeared almost entirely unknown.

What had caused this massacre was, indeed, the first and most pressing question. That they had drunk toxic water seemed obvious.

Now, four years later, a new study suggests, with the evidence of data, a credible hypothesis. It was another climate-driven disaster.

The researchers’ work has been published in the journal ‘Science of the Total Environment’. By analysing, with the help of satellites, the distribution of carcasses in relation to watering points, the team of scientists concluded that the elephants generally travelled just over 100 km (62 miles) from the waterholes before dying, within 88 hours of drinking.

Of the 3,000 waterholes examined, it emerged that those with high concentrations of carcasses in 2020 were the same ones where a larger bloom of cyanobacteria had occurred.

The conclusion is that the elephants were poisoned by water containing toxic blooms of blue-green algae, that is, cyanobacteria. The climate crisis is therefore to blame, since it is increasing the intensity and severity of harmful algal blooms.

The trend of sudden climate-induced diseases, scientists warn, is now widespread globally. In that same year, 35 elephants died in neighbouring Zimbabwe because of an unknown bacterium that entered the bloodstream and was linked to prolonged drought conditions. And not only in Africa. In 2015, 200,000 saiga antelopes died in Kazakhstan because of a climate-linked epidemic of blood poisoning, called haemorrhagic septicaemia.

In southern Africa, the two years 2019-2020 were a devastating one-two punch for water resources. 2019 was the driest year in decades, followed by an extremely wet year in 2020.

These conditions led to a greater quantity of sediment and nutrients suspended in the water, which led to unprecedented algal growth.

‘If water availability changes radically from one year to the next,’ the scientists explain, ‘the conditions favourable to the proliferation of bacteria and algae such as cyanotoxins, which are extremely harmful to many animal populations, increase.’

‘With forecasts that the southern African region will become drier and hotter in the coming years, the conditions described could very easily arise again,’ the experts add.

‘It is therefore important to adopt preventive measures as soon as possible, or we will see new and more massive die-offs.’