Animals will also be affected by the consequences of climate change

The discussion on the consequences of climate change on animals encompasses several issues. On the one hand, commentators raise serious concerns for ecosystems and biodiversity due to the poor ability of animals to survive the increasingly frequent extreme weather events associated with climate change and therefore human activities. On the other hand, they point out the huge damage that economies based on intensive livestock farming could suffer. Finally, the question arises as to the extent to which humans will have to intervene in the forced adaptation processes of other species, or whether we should facilitate this transition altogether through interventions such as genetic modification.

The consequences of climate change on animals is a far more urgent issue than it might appear. In 2021, high temperatures and excessive humidity levels led to the deaths of 650,000 livestock animals in Canada, with major damage to wildlife. In the state of Kansas, which has one of the largest livestock industries in the US, around two thousand cattle died last June due to excessive heat, while in 2015 similar conditions in India caused the deaths of over 17 million chickens.

There is not yet sufficient data on the impact on animals of heatwaves to accurately predict what the actual large-scale consequences for mammals and other creatures will be. This is partly because the temperatures recorded during the current extreme weather events are already higher than in recent decades, and also because most of the existing information only concerns the livestock sector, with little known about the effects on wildlife.

Yet we know that all animals, including humans, are subject to biological temperature and humidity limits, beyond which they cannot survive. For example, the maximum body temperature for most mammals is 38°C, while for birds it is 43°C. These temperature levels are the result of adaptation to glacial and interglacial periods and have been more or less stable for tens of millions of years. As such, they are not values that can undergo rapid changes in response to unprecedented environmental conditions.

The mass extinctions that have followed the major upheavals of the Earth's ecosystem during the history of our planet show that the biological limits of animals are in fact "immutable", according to a specific study. But within 50 to 100 years it is predicted that we will hit temperatures that have not been reached for at least 3 million years: within a century, there is a risk that temperatures and humidity will rise so high that animals’ biological balance will be disrupted beyond a potentially critical range.

Heatwaves are just one of the many problems caused by global warming, especially for wildlife. While livestock and pets can benefit from ventilation systems to survive record temperatures, this is clearly not possible for wild animals. In addition to extreme heat, droughts and fires are increasingly widespread and consistent, both of which force wild animals to abandon their habitats in a short time, disrupting the terrestrial ecosystems to which individual species had adapted over millions of years. As a result, forced interactions between wildlife and humans are expected to become more and more common. «Animals are likely to take risks they would not normally take in search of water», states National Geographic for example, in reference to the increasing cases of wild animals encroaching on urban centres.

The extinction of a species also affects other animals and plants that shared the same natural environment: the consequences can be dire and unpredictable, and may even have an impact on humans, such as the excessive proliferation of a crop-damaging species, for example. It is difficult to say which animals are more vulnerable than others because there are so many factors at play. In general, however, in line with the findings of the Earth Institute of Columbia University, it is thought that animals will respond to climate change in three ways: by moving, adapting or becoming extinct.