Global warming is a term that is quite recurring in our society. We hear people talking about it in media, in school, etc. Most of us know that global warming is the fact that Earth’s average surface temperature is increasing due to the greenhouse effect, which is the process where greenhouse gases such as carbon dioxide (CO2) prevent some infrared rays from escaping from the atmosphere and redirect them towards Earth.
This causes a rise in the average surface temperature. Some of its effects are quite known, such as the melting of polar ice caps and glaciers, causing the rise of sea levels, along with flooding and erosion; or things such as wildfires and droughts. But the impact it has on wildlife is something that is less talked about.
Animals are forced to relocate in order to survive. As temperatures climb, they seek cooler territories to settle. Therefore, they move towards the poles and move to higher elevations. Mountain-dwelling animals climb higher, and marine species drift towards cooler water near the poles. Moreover, melting sea ice threatens species who rely on the ice for hunting, resting and breeding, like polar bears, walruses and seals.
25% of marine species that live in or around coral reefs are impacted because the reefs are at risk of bleaching. This happens through the effects of ocean acidification (oceans absorb carbon dioxide, which makes them become more acidic).
Global warming affects all kinds of ecosystems. Tropical forests are becoming warmer and drier, and the Amazon rainforest could become a savannah within the next 100 years, according to some scientists, which would make it an unsuitable habitat for most of the animals living there today.
Furthermore, climate change also impacts animals’ migration. Bird migration patterns shift, making these journeys even more dangerous than they already were. Whales are entering unfamiliar waters and traveling closer to shipping routes, putting them at risk. Elephants are coming into closer contact with human settlements.
Global warming also causes animals to shrink in size. Climate change doesn’t just affect the ecosystems they live in, it also impacts their bodies. Animals living close to the upper temperatures present smaller body masses and shorter body lengths, which help them lose heat more efficiently. Unfortunately, it means that they dehydrate more quickly.
Another consequence is the so-called phenological mismatch. Many animals time their migration and breeding around seasonal cues and insects and plants react to temperature. Therefore, because of global warming, temperatures shift, and plants and insects emerge at different times than usual. Consequently, this badly affects animals who rely on them and view them as food sources.
The rise in temperature also allows mosquitoes and ticks that carry diseases to expand and establish into regions they couldn’t access before. This threatens wildlife who never encountered those diseases before.
Consequently, all of these changes put species at risk of extinction because they sometimes struggle to adapt or just cannot survive them. Animals can migrate towards the poles or climb towards higher altitudes, but there is a limit to that, as they won’t be able to do that forever.
A large-scale meta-analysis published in Science Insights projected that climate change threatens roughly 7.6% of all species with extinction, averaged across all emissions scenarios. At just 2°C of warming, 8% of mammals will lose half their habitat, and 99% of coral reefs will vanish. As a result, animal species will struggle to survive, and biodiversity will drop.