2.2.5 Impacts of heating on land-based wildlife

internal references to solve:

  • part 3 How-are-we-destroying-our-wildlife
  • part 5 What-will-our-world-look-like-in-2050-if-we-don%E2%80%99t-take-radical-action-now
  • part 5 What-will-our-world-look-like-by-the-end-of-the-century

"Personally I find the results alarming. Species attempt to adapt to changing environment, but they cannot do it at a sufficient pace to ensure that populations are viable. Climate change has caused irreversible damage to our biodiversity already, as evidenced by the findings of this study. The fact that species struggle to adapt to the current rate of climate change means we have to take actionimmediately in order to at least halt or decrease the rate." Viktoriia Radchuk, Leibniz Institute for Zoo and Wildlife Research in Germany

Land-based creatures are extremely sensitive to changes in climate. This is because, over millions of years, wild species have evolved to have finely tuned adaptations that allow them to live in the specific climate of their local environment. For example, many are adapted to live at certain temperatures and with certain amounts of rainfall – and are also very sensitive to changes in the daily and seasonal variation in these factors. In fact, the local climate is the primary factor that controls where species live.

What this means is that when the climate changes at any particular location in the world, it has direct and powerful impacts on the local creatures.

We are already seeing many devastating and direct effects of climate change on wildlife, for example, trees dying through insufficient water and animals losing their ability to forage for food because of heat stress - leading to local extinctions.

We are also seeing impacts due to changes in the timings of the seasons, such as the early springs that we are experiencing in some parts of the world (which have become a feature on The News). The problem is, such changes in seasonality are experienced unequally by different species, which leads to mismatches in the timing of important life events for animals and plants. For example, pollinating insects are coming out of hibernation before flowers emerge, and the migration of birds is out of synchrony with peaks in abundance of their prey, leading to poor reproduction and death.

In addition, as weather extremes increase in intensity and frequency due to climate change, wild plants and animals are suffering from events such as droughts, wildfires, and floods. These events alone are pushing some species towards extinction. The intense Australian bushfires of early 2020 have destroyed the habitats of many species, with at least 50 rare animals and plants having had over four fifths of their habitat areas affected. It has been estimated that over 1 billion animals were also killed, and it is feared that this, in combination with loss of habitats, will lead to local extinctions of species like the koala.

Given that today’s climate is changing so fast that there is no time for creatures to adapt, often the only option for species is to try to move - in order to look for new areas that have a suitable climate for them to live in. This may sound straightforward, but, in a rapidly changing climate, species have to shift their ranges remarkably fast. Even amongst land mammals, which are much more mobile than plants or insects, it is estimated that, at best, 30% of species will not be able to shift fast enough to keep up with climate change. While some species are indeed starting to shift their ranges, this is generally taking place slower than the climate is changing - and there are many species that are not shifting, or that are only shifting only very slowly.

An additional challenge to creatures being able to shift location is that creatures within an ecosystem need to have the very specific species that they interact living alongside them. For example, plants rely on their pollinators, predators on their prey, and herbivores on the plants they eat. So if different creatures in an ecosystem are not able to shift at the same rate, ecological communities will become unstable.

To make matters worse, even if species were to be able to move, many of the cooler or more sheltered places on Earth (that creatures could use to take refuge from increasing temperatures) have now been degraded, fragmented or colonised by human activities.

Plus, there are those animals that require conditions of extreme cold for their survival. As global temperatures rise rapidly, there is nowhere on Earth for them to escape to. For example, polar bears usually stand on floating blocks of sea ice when they’re out hunting for seals in the freezing Northern seas. However, due to rising temperatures sea ice is rapidly melting so they are now forced to walk or swim enormous distances to get to any remaining ice, or to forage for food on land where they have difficulty in finding prey. Some bears have resorted to travelling south and scavenging for food in places where humans live. In February 2019, 50 polar bears invaded the remote Russian town of Belushya Guba. Videos posted on social media showed the scrawny starving creatures picking their way through rubbish bins, rummaging through dumps and even roaming around inside buildings. Sea ice and land-based ice sheets are also critical for organisms such as whales, seals, and sea birds.

Land-based wildlife is not only being enormously impacted by climate change, but also by land degradation, deforestation, pollution and over-consumption. For lots more information on the devastating impacts that humans are already having on wildlife, see section on how we are destroying our wildlife.