Unlikely the Biodiversity Crisis Will Improve Any Time Soon

Around a fortnight ago I wrote a hastily penned post about the precarious state of biodiversity — it turned out to be one of the most-read posts in ConservationBytes‘ history (nearly 22,000 views in less than two weeks).

Now, let’s examine whether this dreadful history is likely to get any better any time soon.

Even if extinction rates decline substantially over the next century, I argue that we are committed to an intensifying biodiversity extinction crisis. The aggregate footprint from the growing human population notwithstanding, we can expect decades, if not centuries, of continued extinctions from lag effects alone (extinction debts arising from previous environmental damage engendering extinctions in the future)¹.

Global vegetation cover and production are also likely to decline even in the absence of continued habitat clearing — the potential benefit of higher CO₂ concentrations for plant photosynthesis is more than offset by lower availability of water in the soil, heat stress, and the frequency of disturbances such as droughts². Higher frequencies and intensities of disturbance events like catastrophic bushfire will also exacerbate extinction rates³.

However, perhaps the least-appreciated element of potential extinctions arising from climate change is that they are vastly underestimated when only considering a species’ thermal tolerance⁴. In fact, climate disruption-driven extinction rates could be up to ten times higher than currently predicted⁴ when extinction cascades are taken into account⁵.

Just like the failure of the Convention on Biological Diversity’s (CBD) 2010 Biodiversity Target (“… a significant reduction of the current rate of biodiversity loss at the global, regional and national level as a contribution to poverty alleviation and to the benefit of all life on Earth”), it now appears that most of the CBD’s Aichi Targets for 2020 will not be met⁶.

More broadly, most of the nature-related United Nations Sustainable Development Goals (SDGs) (e.g., SDGs 6, 13, 14, 15) are also on track for failure^6,7, largely because most SDGs have not adequately taken into consideration the linkages between them, or of their interdependencies^7-9.

So, while ecosystem services and the species that provide them are declining globally, much of our high current wealth⁶, health¹⁰ and well-being¹¹ is directly owed to the increased rate of extraction of the goods provided by nature, including energy, timber, fish, agricultural products, and various other materials⁶.

Indeed, the extraction of living materials from nature has increased by more than 200% since 1970. Therefore, the apparent paradox of high average quality of life despite a mounting environmental toll has come at a great cost to the stability of humanity’s life-support system. In other words, we are robbing Peter (nature) to pay Paul (economic enhancement).

It can be difficult to understand this apparent paradox for people not immediately exposed to challenging conditions faced by many in low-income countries. However, the ecological footprint — measuring the ecological ‘assets’ that a human population requires to produce the natural resources it consumes and to absorb its wastes (driven principally by population size and affluence¹²) — demonstrates clearly that the current robbing-to-pay model is near to the end of its lifespan.

While consumption patterns are of course highly uneven among nations, globally our ecological footprint means that we are consuming 1.6 times the regenerative capacity of the Earth to provide the goods and services we use each year.

The bank account might still hold some money, but we are spending far more than we are saving¹³ — soon the account will have insufficient funds for many of us to continue living as well as we do. Even the World Economic Forum now recognises biodiversity loss as one of the top threats to the global economy¹⁴.

As you can probably now appreciate, I’m not overflowing with abundant hope.

CJA Bradshaw

References

1. 1. Dullinger, S. et al. Europe’s other debt crisis caused by the long legacy of future extinctions. Proc. Natl. Acad. Sci. USA 110, 7342-7347, doi:10.1073/pnas.1216303110 (2013)
   2. Xu, C. et al. Increasing impacts of extreme droughts on vegetation productivity under climate change. Nat. Clim. Change 9, 948-953, doi:10.1038/s41558-019-0630-6 (2019)
   3. Vincenzi, S. Extinction risk and eco-evolutionary dynamics in a variable environment with increasing frequency of extreme events. J. R. Soc. Interface 11, 20140441, doi:10.1098/rsif.2014.0441 (2014)
   4. Urban, M. C. Accelerating extinction risk from climate change. Science 348, 571, doi:10.1126/science.aaa4984 (2015)
   5. Strona, G. & Bradshaw, C. J. A. Co-extinctions annihilate planetary life during extreme environmental change. Sci. Rep. 8, 16724, doi:10.1038/s41598-018-35068-1 (2018)
   6. Díaz, S. et al. Pervasive human-driven decline of life on Earth points to the need for transformative change. Science 366, eaax3100, doi:10.1126/science.aax3100 (2019)
   7. Messerli, P. et al. Expansion of sustainability science needed for the SDGs. Nat. Sustain. 2, 892-894, doi:10.1038/s41893-019-0394-z (2019)
   8. Bradshaw, C. J. A. & Di Minin, E. Socio-economic predictors of environmental performance among African nations. Sci. Rep. 9, 9306, doi:10.1038/s41598-019-45762-3 (2019)
   9. Bradshaw, C. J. A. et al. Testing the socioeconomic and environmental determinants of better child-health outcomes in Africa: a cross-sectional study among nations. BMJ Open 9, e029968, doi:10.1136/bmjopen-2019-029968 (2019)
   10. World Economic Forum. The Global Human Capital Report 2017. (World Economic Forum, Geneva, Switzerland, 2017)
   11. Díaz, S., Fargione, J., Chapin, F. S. & Tilman, D. Biodiversity loss threatens human well-being. PLoS Biol. 4, e277 (2006)
   12. Dietz, T., Rosa, E. A. & York, R. Driving the human ecological footprint. Front. Ecol. Environ. 5, 13-18, doi:10.1890/1540-9295(2007)5[13:DTHEF]2.0.CO;2 (2007)
   13. Ehrlich, P. R., Kareiva, P. M. & Daily, G. C. Securing natural capital and expanding equity to rescale civilization. Nature 486, 68-73 (2012)
   14. World Economic Forum. Global Risks Report 2020. 15th Edition. (World Economic Forum, Geneva, Switzerland, 2020)