It is no secret that climate change and environmental negligence have been worsened by human activity and accelerated industrialization over the past century, and that wildlife greatly suffers as a result. A recent study published by the World Wildlife Foundation (WWF) analyzes the most recent data of animal populations worldwide, and shows an average 60% decrease in vertebrate populations globally.
Polar bears’ habitat and food sources are shrinking at an alarming rate. Image credit: Skeeze.
The Living Planet Report 2018, a recently published landmark study from the WWF, thoroughly investigates the myriad of human-caused effects on the natural world, and it’s not a pretty picture.
From 1970 to 2014, our planet has lost over half of our wildlife population, as measured by population size changes according to the Living Planet Index.
Analysis of nearly 17,000 populations that represent 4,000 vertebrate species spread across the globe, shows a mass average 60% reduction in population sizes.
The most dramatic change was seen in Central and South America which make up the Neotropical zone, where abundance counts of over 1,000 measured populations have dropped by about 4.8% every year since 1970, equating to an overall decline of 89% in less than a half-century.
When we step off solid land into freshwater, an 83% decline has been reported across 880 species spanning mammals, birds, amphibians, reptiles, and fishes.
These numbers show the changes specifically in the populations that were measured, and therefore don’t represent the entire scope of animals’ biodiversity.
The Living Planet Index (LPI) for each realm: the white line in the LPI graph shows the index values and the shaded areas represent the statistical certainty surrounding the trend (95%); threat data is available for 3,789 — just under a quarter — of the populations in the global LPI. Image credit: WWF.
Study Technique
It is important to keep in mind that this index is a metric, or a standardized way to estimate the unquantifiable, of our planet’s biodiversity, which we will never be able to measure with absolute precision.
Therefore the Zoological Society of London and the WWF teamed up to create a model that controls for biases that influence the way that these counts are established.
These biases include the non-uniform distribution of sites of data collection (most measured populations were from North America) and the relative ease of estimating different species (we are more likely to accurately count the number of rhinoceroses than field mice).
The most common techniques for measuring animal populations include direct counting, camera traps, tracking devices, and analyzing tracks.
These results, while striking, must be further contextualized by the fact that vertebrates make up only 3% of all living animals.
Population data for invertebrates is much more scarce, as they remain elusive to study, but published reports show a similar trend of defaunation, or the loss of abundance and variety of species, among invertebrates as well.
The loggerhead turtle (Caretta caretta) trapped in a drifting abandoned net, Mediterranean Sea. Image credit: Naturepl.com / Jordi Chias / WWF.
Humanity’s Impact
The end of the last ice age approximately 12,000 years ago, marked the beginning of the geologic era known as the Holocene epoch.
However, there is mounting pressure to redefine this age as the Anthropocene, taking it’s anthrop– root from the Greek for human.
There is evidence that the impacts of the physical byproducts that humans leave behind on the planet as well as our influence on flora, fauna, and the inorganic geochemical makeup of the earth will mark a distinct period of time in Earth’s broader history.
The results of this latest Living Planet Report adds evidence indicating that we are well in the midst of the most recent mass extinction, the 6th in a line of extinction events that each saw the immediate expiration of 50-90% of species at their respective occurrences.
Many current outlooks are grim, largely because there is little that is being done on an institutional scale large enough to effectively counter this devastation, in hand with opposition suggesting that since it is all in the course of nature, it requires no intervention from us.
However, we are more dependent on our planet’s biodiversity than we may give credit for.
“For too long we have taken nature for granted, and this needs to stop,” says Marco Lambertini, Director General of WWF International.
For example, coral reefs are animals that serve many purposes as a habitat for marine life, a natural source for medicines, and as underwater barriers that protect against coastal flooding.
However, increasing ocean temperatures is causing widespread coral bleaching, which will lead to an estimated 91% increase in costs related to flood damages worldwide for so-called 100-year storm events.
These benefits plus the many more invisible ones that are omnipresent contribute to an estimated $125 trillion per year value of the total ecosystem.
The Living Planet Report 2018 indicates that the most substantial human-exacerbated threats to biodiversity include pollution, habitat destruction, unsustainable overfishing, and climate change.
Now more than ever, it is critical that we factor in environmental impacts to our everyday decision-making.
With an exponentially increasing population, the force of our cumulative individual choices has immense impact.
However, this is not a lost cause, and there are steps we can take to mitigate our impact on climate change and biodiversity depletion.
These include attention to our diet (cutting down on meat), avoiding unnecessary expenditures of energy (carpooling, walking to work), and attention to environmental impacts among our day-to-day decisions (do I really need to use a plastic straw?).
Sacrifices are required to implement changes that will positively impact our environment, so the question turns to us as we must ask ourselves, “is our planet’s health worth it?”
