‘A plague on both your houses’

Romeo & Juliet, Shakespeare

Spoiler alert – humans are the ones causing millions of species to be pushed to the brink (literally, over 1 million plant and animal wildlife are now threatened – IPBES Report, 2019)  so no, you don’t have to wait to the end of this story to find out ‘who dunnit’ because this story isn’t about finding the culprit. Since public consciousness of wrongdoing towards wildlife is increasingly well established, it’s worrying that public (and thereby political) will seems lacking in the scale of biodiversity loss we are talking here. And so I think to myself, maybe that is why there is this lacking, because there may be a knowledge gap in people’s understanding of quite how ‘mass’ of a biomass loss there has been and will continue to be in the very near future (at least that is my hope, for if people did know and continued with a lack of concern and commitment to change…well, sign me up for a one way ticket out of here).

And so, in this piece I uncover the true extent of the biodiversity crises we are experiencing in comparison to the average extinction rate (from hereon called the background extinction rate – Turvey, 2019) and talk to the top major threat factors posed by human activity. In the final body of this blog, I’ll then circle back to what this means for us as a sort of ‘kalmic retribution’ if we don’t respond to this crisis and cover two main lines of debate for valuing biodiversity.* Finally I’ll conclude on some high level steps you can take to personally respond, and of course explain why on earth I have used that famous shakespeare quote at the top 

*Note there is a common misconception of what the term biodiversity actually means, usually public thinking attributes this to the species level. However, this can be applied across the biomass scales: genetics > species > ecosystems > communities. Of course there are connections across these scales, but it’s important to consider, beyond a species, what a decline in genetic biodiversity means – leave that one with you!

What is the sixth mass extinction then? Prove it!

I enjoy skeptical readership, so let’s pretend (or not) that you don’t take my word for this mass extinction. Here’s the sciency part:

The background extinction rate – Recent scientific analysis used data spanning historic stratigraphic eras for thousands of mammal species, different time intervals were used from years to millions of years, and for these intervals the mean extinction rate and variance were calculated. This lead to a figure of just under 2 E/MSY (that is to say, 2 extinctions per 100 years per 10,000 species)

The sixth mass extinction – Scientists used this background extinction rate and then applied it to the current E/MSY data in the last century. Findings demonstrated the rate is 100 x higher than the background extinction rate. 

Let’s just replay that one – 100 times higher than the background extinction rate – meaning the number of species that have died out in the last 100 years would have taken up to 1000 years normally  – on average and dependent on the given species taxa of course (Ceballos, 2015). Caveat here that the background extinction rate was only applied to mammals, but given what is going on in our seas (and see my searies for more on this!) it’s likely the figure would be worse if such marine life was taken into account. 

And it’s no coincidence that roughly 100 years ago we embarked on a little thing called the industrial revolution people. In today’s accelerated anthropocene where we produce (and reproduce) exponentially, our consumption demand grows with it. We need and demand more; more than Earth naturally regenerates. This is known as ecological overshoot, calculated at 156% (Bradshaw, 2019). To make that more real, in a given year with this ecological overshoot, humans consume more than Earth restores by August. More on this shortly. 

Wow, those are pretty awful stats. What are the main human causes?

As mentioned, humans have been identified by the scientific community as the ultimate cause of such monumental biodiversity loss, but there are some clear dissections that have been made:

Climate Change

no major explanation needed here really, we’re causing it, and it is wreaking havoc on the Earth’s biodiversity. And this in itself has an amplifying feedback loop to the rate of climate change, for example with a reduction in blue algae, which absorbs carbon, this carbon instead remains in the atmosphere, further speeding up climate change. Temperatures rising as a result of fossil fuel burning and land change (deforestation for example) means a whole heap of climate disruption I won’t go into, which is why the 1.5 degree limit was agreed to forming the Paris Agreement. What I will just mention on this point though is the recent IPCC report, the leading body reporting on the state of climate change internationally, finds: 

unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5°C or even 2°C will be beyond reach. (IPCC Special Report Press Release, 2021). 

Population growth:

The figures for human population growth in recent years is quite eye watering, doubling since the 1970s, and set to be c. 9.9 billion by 2050 (Bradshaw, 2019). Now that’s a lot of mouths to feed and bodies to house. Which is why urbanization and agriculture (particularly this latter) has meant land usage has dramatically reduced what once was wild, and exploited it for human use. Indeed, urban areas have doubled since 1992 and (deep breath) over 1/3 of Earth’s surface and 75% of freshwater sources are designated for crop and livestock purposes (United Nations, 2019). Habitat loss poses an obvious but significant threat to biodiversity, but not only that, the human uses of these areas ‘leak out’ into other natural environments – the chemical run-off from fertilisers into our oceans, the ‘edge effects’ that occur next to urban developments (e.g. did you know the noise pollution from a road affects how birds sing?) 

Interestingly, with many other species, a natural phenomenon occurs as its population grows like this, called density feedback:

 ‘as a population approaches its environmental carrying capacity, average individual fitness declines’ (Bradshaw, 2019)’

This means that, normally, as the availability of critical resources is less than the cumulative need of the population, it naturally declines. But, for us, we continue to evade our natural carrying capacity as we have leveraged technology and exploited more and more resources globally. Finally time for my plague of locusts analogy to kick in. Locusts are well known for rather spontaneously swelling in abundance, reaching numbers sometimes in the billions if the swarm is successful. The metaphor here is that locusts don’t ‘give back’ to their environment, they simply devour everything in sight. The swarm exponentially grows. And so they must move faster and faster so that they can find enough resources to sustain its gigantic numbers – like nature’s colonialists. The more they expand, the faster natural resources are depleted, the faster they must move. Until eventually they can’t move quick enough and the swarm dies off….(now you’ve got that nice image, picking up this analogy again in the wrap up)

My personal argument here though is not that our numbers are unsustainable, but it is HOW we are living that is unsustainable.  

Political and environmental institutional impotence. 

If only there was a viagra equivalent for this one…

Up until very recently we have seen a rise in populist, anti-environment leadership in many countries – the US, Brazil, Australia. The divides between wealth and access to public services make it difficult to align on an environmental agenda nationally, let alone internationally (Bradshaw, 2019). Therefore international law around taking biodiversity into account when making national decisions does not exist, and of course national legislation is provoked largely by the political leadership. And so, political impotence leads to a lack of legal enforcement of any standard biodiversity protective measures. 

What about international cooperations like the COPs or the Aichi Biodiversity targets? Well they have been a bit of a flop (cough) too. None of the Aichi Biodiversity targets set for 2020 were achieved and the current 17 Sustainable Development Goals (SDGs) are also not on track (Bradshaw, 2019). Why are they continuously ineffective? Well there’s been a lot of speculation, some regarding the above i.e. that there is a lack of legal enforcement to drive the commitments through, a failing of conservation areas to be managed effectively but also things like a lack of data and transparency to accurately measure against these targets in the first place. It’s all a bit murky, but what this means for biodiversity is that the institutions in place that should be focusing on its preservation are, in fact, failing. 

Natural resource exploitation. 

Ok final quick point on this, there are several outlets for this factor – overfishing/ destructive fishing methods (like dynamite fishing), illegal wildlife trading, illegal deforestation, these all lead to rapid decline in ecosystem health and species extinction. You wouldn’t believe it, but as much as 30,000 species are estimated to go extinct annually as a result of the illegal wildlife trade for pets, food sources or, of course, decoration (ivory would probably be first in your mind) (Lai, 2022). In fact, conservation areas struggle with protecting against these threats, such as illegal fish trawling in marine protected zones, or protected reserves in Africa being continuously monitored with armed guards against the very real threat of equally armed and dangerous poachers. 

The impacts on us – Ecosystem services

Ecosystem services (ES) is exactly what is says on the tin – these are benefits realised by humans from the natural ecosystems that surround us. These benefits are wide ranging and are categorised into 4 main areas – regulation, provisioning, cultural and supporting (Pearce, 2023) – think anything from air purification, water/ nutrient cycling, storm & flood protection through to more standard provisioning based – food, medicine, wood etc. And so these invisible to visible services have huge value, whether that be directly attributed to economic terms or not. 

Which brings me on to my next point around value. There are two main stances on this – intrinsic and market value. Intrinsic value is around the concept that species ‘should be conserved simply because they exist: they are the product of a long history of continuing evolution…and so they have the right to a continued existence.’ (Aho, 2008) Therefore this is a purely altruistic valuation on life forms, not for personal gain but for a moral notion of what is right. However, market value is applied when there are obvious benefits – be they monetary or usually product based (a la I cut down this tree species, I can use it for firewood). Therefore, even if we apply this largely ‘selfish’ value onto biodiversity, it is hugely important, in sustaining us through the critical ES we directly or indirectly experience. 

Wrapping up… 

So, you’ll be glad that we’re returning back to our plague of locusts and our good old friend Shakespeare. Taking into consideration the ecosystem services biodiversity provides us free of charge, the plague is on both our houses – biodiversity decline equals our decline too. We can continue to devour everything in sight and move faster and faster and FASTER until…eventually…our frenzied swarm must end…OR we can change. We can find a balance that symbolises our consumption rate equalling the Earth’s regenerative capacity. In other words, we can enable our vibrant species and ecosystems to survive through co-habitation and conscious management of what we take matching what Earth can restore. The headline from the most recent COP 15 montreal biodiversity conference indicates just this – 30% of Earth to be given over to biodiversity protection by 2030 ( (United Nations, 2022) but, as we’ve explored, these targets are futile if the political will is not there to back it. So what can you do about this?

• Engage in the politics – look at party manifestos relating to environmental targets and governance, challenge your employer on what lobbying they are doing or targets they have for reducing their environmental impact (check this awesome vid out for more on the topic of corporate ‘externalities’ – no time to cover here I’m afraid). Political will is, in functioning democracies at least, defined by the public will.  

• Spread the word – as I’ve mentioned, I think this topic isn’t well understood in its sheer scale and how many species will disappear entirely in the all too near future. Speak to both the intrinsic and market value of biodiversity when building your case – alas many do still think of things in purely economic terms – luckily this is a pretty easy sell to make 

• Put your hand in your pocket for science and conservation. There is still so much we have yet to uncover about the value natural flora and fauna could provide us – the more we uncover, the more compelling an argument we can make to defend it. And conservation areas are largely funded through a ‘polluter pays’ approach (i.e. the tourists and private companies contributing to the areas continued management as compensation) but with greater funding they can go further and deeper with their measures, moreso liberated from that funding model which has its own trade offs and conflicts of interest, empowering their biodiversity agenda. 

So, we are standing on the precipice of the sixth mass extinction, and it’s a daunting challenge to stop it. But isn’t the alternative of a world void of the beautiful biodiversity we have a deeply disturbing one? One without our thriving coral reefs, tropical rainforests, wild woodlands. I don’t want to be a locust any more, do you?

References:

• IPCC, ‘Climate change widespread, rapid, and intensifying – IPCC’, IPCC’s Sixth Assessment Report (AR6) Press Release (2021). 
• Bradshaw, C.J., P.R. Ehrlich, A. Beattie, G. Ceballos, E. Crist, J.  Diamond, R. Dirzo, A.H. Ehrlich, J. Harte, M.E. Harte and G. Pyke ‘Underestimating the challenges of avoiding a ghastly future’, Frontiers in Conservation Science 1 2021, p.9.   
• Ceballos, G., P.R. Ehrlich, A.D. Barnosky, A. Garcia, R.M. Pringle and T.M. Palmer ‘Accelerated modern human–induced species losses: Entering the sixth mass extinction’, Science Advances 1(5) 2015.  
• Turvey, S.T. and J.J. Crees ‘Extinction in the Anthropocene’, Current Biology 29 2019, R982–R986
• United Nations ‘UN report: nature’s dangerous decline “unprecedented”; species extinction rates “accelerating”’ (2019). 
• United Nations, ‘COP15 ends with landmark biodiversity agreement’, UNEP Environment programme (2022). Available at: https://www.unep.org/news-and-stories/story/cop15-ends-landmark-biodiversity-agreement.
• Pearce, N., ‘what are ecosystem services?’, Earth.org (2021). 
• Aho C.J.R., ‘The value of biodiversity’, Brazilian Journal of Biology 68(4) 2008. 
• Lai, O. ‘Biodiversity loss and definition and examples’, Earth.org (2022).
• Phavan, S., ‘Put a value on nature!’, TedX, 2011.