In the majority of media outreach articles regarding climate change, much of the focus has been on the effects on humans and how they will adapt. This sense of anthropocentrism is not new amongst our society, as we too often neglect considering the impacts of climate change on animals and ecosystems worldwide. It’s important to discuss this topic because the extent of climate change impacts will result on a large scale need for adaptation, for biodiversity itself and for the humans who are dependent on it.
In the past, many animals have had to adapt to changing climates, both locally and regionally – so how is this climate warming any different? Much research has suggested that the rate of change we see today is too fast for many species to keep up with. There are a huge amount of species, both terrestrial and marine, struggling in their current climates due to disruption to their ecosystems. One species particularly at risk is the turtles, because the sex of their offspring is determined by the temperature of the eggs’ surroundings during development; warmer temperatures produce females compared to cooler temperatures. This highlights how increasing temperatures due to anthropogenic warming will likely result in increased local extinctions due to a bias towards female offspring and could eventually be detrimental to the functioning of the turtles.
Percentage of female offspring with increasing temperature (Source: National Save The Sea Turtle Foundation)
The turtles are only one of the species mentioned in the WWF Article, 2015 on the climate change risk assessment for wildlife, the following list includes some of the most important species WWF is working on and why they are vulnerable to climate change.
Polar Bears – depend upon sea-ice environment
Snow Leopards – indirect impacts of climate change due to habitat encroachment
Giant Pandas – feed exclusively on bamboo
Tigers – small population size
Monarch Butterflies – dependent on the environment for reproduction, migration and hibernation cues
African Elephants – water dependence
Asian Elephants – native food sources effected
Mountain Gorillas – confined range
Cheetahs – very low genetic diversity
This list is obviously not exhaustive, but why are only these animals mentioned and why do the WWF focus on these animals in particular? We also have to acknowledge how biodiversity losses can impact the food chains and natural cycles occurring in the environment.
One of the most crucial animals to the food chain in the Antarctic is krill; these shrimp like creatures will be largely effected by the warming of the southern ocean and altering sea ice patterns in the Antarctic ocean yet they are not mentioned by the WWF – one of the largest environmental organisations trying to challenge threats to nature. Is it because we can relate less to krill than we can to a fluffy panda? Or is it because losing the WWF-listed animals will impact our lives as we can’t see elephants on our gap-yar travels or on safari?
The real questions: are important species being overlooked? Are the vulnerabilities of other species being exaggerated to appeal to the public? Is this an environmental injustice?
Antarctic Krill – not the cutest of creatures, but one of the most effected by the climate crisis. (Source: NOAA NMFS SWFSC Antarctic Marine Living Resources (AMLR) Program)
The Options
Unless species can successfully alter their behaviours to fit with the changing conditions, it’s unlikely they will cope. As reported by a recent study by Beever et al., 2017, the animals have 4 options:
1. Moving
2. Adapting
3. Acclimatising
4. Dying
Research papers, in line with the Paris Agreement and other climate agreements, have suggested that a temperature rise of 4.5˚C would see up to half the animals and plants in some of the world’s most biodiverse areas could go extinct by 2100 (Warren et al., 2018). But despite the severity of these claims, it should be considered that many models fail to accurately predict biodiversity losses by assuming there’s no adaptive capacity amongst the animal kingdom. Animals have had to adapt to changing local and regional climates before, but will they be able to do it again and at an accelerated rate?
The National Geographic expressed that the most long-lived species with low genetic variabilitywill have a lower adaptive ability, e.g. cheetahs. This is because a lack of genetic variability increases the potential of extinction; not only does it make species more susceptible to disease, but also reduces the ability for a species or population to evolve in response to changing environments. Therefore, this highlights the importance of improving genetic variability, particularly when facing the issue of changing climates.
Is it all doom and gloom for the future of biodiversity?
Difficulties arise when making judgements about behavioural changes or adaptation strategies among species as evidence must be long-term to be considered reliable (The National Geographic). This means there are relatively few studies which can genuinely confirm that species have adapted in light of climate change.
One recurring theme appearing in the majority of papers I’ve read relate to animals changing the colour of their coats and feathers. A study published this year by Scott Mills, found a direct correlation between seasonal coat colour of animals in the northern hemisphere and the changing climate. Results suggested that animals who have winter white coats are retaining their brown coats year round due to the impacts of a shorter snowy season. In finding these patterns, it is possible to locate and identify polymorphic zones; areas of greater variation and therefore higher evolutionary potential. These polymorphic zones are deemed as hotspots for ‘evolutionary rescue’, and so research such as this can help guide conservation and highlight where human intervention is needed to help animals deal with climate change impacts.
Another ecosystem which, quite surprisingly, appears to be adapting well to climate change is the coral reefs. A study by Palumbi et al., 2014, on a coral reef in the U.S. National Park of American Samoa, showed significant resilience. For a long time, coral reefs have been regarded as a particularly vulnerable ecosystem and as a result, the effects of coral bleaching are now widely understood. The native corals in Samoa, however, show both short-term acclimatising techniques and perhaps long term adaptive strategies through an improved heat tolerance. Palumnbi suggests that natural selection may have changed the genes of the hot-pool corals, allowing the most heat tolerant to continue surviving, thriving and producing more offspring. This links climate change with genetic evolution and emphasises that the adaptive abilities of the ecosystem may slow and reduce the likelihood of our previously pessimistic predictions of the extinction of coral reef systems, becoming a reality.
Summary
What we should learn from this is that adaptation stretches beyond the realms of human society and climate change has wider implications on a broader range of ecosystems. The aim of this post was to emphasise the need to protect biodiversity. Unnatural climate changes are an anthropogenic result, so it could be argued that we have a duty to reach out and prevent the impacts of climate change. But what can you do? Read this blog post to get some inspiration on how YOU can prevent biodiversity loss!
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