“In the drive to sustain the $125-trillion a year explosion of human consumption we have, since 1970, devastated 60% of the vertebrate species on Earth,” ran the editorial in City Press on 4 November 2018. It based this number on the 2018 edition of the Living Planet Report, published every two years by the Worldwide Fund for Nature (WWF).
The Guardian wrote: “Humanity has wiped out 60% of animal populations since 1970, report finds,” adding: “The huge loss is a tragedy in itself but also threatens the survival of civilisation, say the world’s leading scientists.”
Leaving aside the description of WWF activists as “the world’s leading scientists”, these headlines are dead wrong. They’re just not true.
The WWF itself said: “In less than 50 years, we’ve seen an overall decline of 60% in population sizes of vertebrate species.”
It calls this number the “Living Planet Index”.
Those well-versed in the art of alarmist spin might detect that the phrasing by the WWF is slightly different from the claims in the media. It’s still deceptive and ambiguous. For example, “overall” actually means “average”. It does not refer to the number of species, nor the total global wildlife population, as the media reports claim.
We decidedly have not lost 60% of all vertebrate species. Since 1970, only four species of mammal went extinct, and one more went extinct in the wild. Perhaps two dozen bird species went extinct since 1970, although most of them remain classified as critically endangered because we can’t be sure.
The IUCN Red List classifies 361 vertebrates as extinct in all of recorded history, which is only 0.78% of the 46,556 species and subspecies that have been assessed. Extinctions are not all that common.
The 60% figure is also not the number of individual animals that have been lost since 1970, as most of the media reports suggest. It is an average of each species’ population loss. All species are weighted equally, no matter their actual population size.
In The Atlantic, Ed Yong does an excellent job of explaining the WWF’s figures:
“To understand the distinction, imagine you have three populations: 5,000 lions, 500 tigers, and 50 bears. Four decades later, you have just 4,500 lions, 100 tigers, and five bears (oh my). Those three populations have declined by 10%, 80%, and 90%, respectively — which means an average decline of 60%. But the total number of actual animals has gone down from 5,550 to 4,605, which is a decline of just 17%.”
And those are just hypothetical numbers. In reality, we don’t know the percentage of wildlife we might have lost since 1970. The WWF only sampled 4,005 species, which is a small fraction of the 63,000 known species of vertebrates, and ignores the millions of species of invertebrates altogether. A few species with low population numbers, but showing a dramatic decline, can heavily affect the WWF’s dramatic final number, although it is quite dishonest.
One chart in the report inadvertently gives the game away. At face value, it appears to contradict the headline finding of the Living Planet Report.
I drew some guidelines on it. Reading off the chart, the “percentage decrease in mean species abundance” was about 19% in 1970, from some unspecified baseline that clearly long predates 1750. By 2010, that decrease had risen to just under 31%.
Now a hike from 19% to 31% is indeed a 60% rise, as suggested by the Living Planet Index. Yet the absolute decline in mean species abundance since that unspecified baseline of long, long ago, is shown to be only 31%.
The more honest calculation would have been to consider the remaining average populations of 81% in 1970, and noted that the decline to 69% in 2010 amounts to a decline from the 1970 baseline of 14%. But a 14% decline doesn’t make screaming headlines the way 60% does, does it?
That a decline of 60% since 1970 would leave us with average species populations of 69% is probably not what you expected. That’s because it takes a special kind of statistical manipulation to suggest this. The Living Planet Index is deliberately deceptive, designed not to inform, but to alarm.
Of course, before 1750 we had lots of scientists spread around the world counting animals, so at least we have a firm grasp on the true value of the baseline. Oh, no, wait, we didn’t, and we don’t. That baseline is entirely arbitrary.
The other theme of the Living Planet Report, about the ecological footprint of humanity, is equally flawed. I dissected this part of the 2014 report in a column at the time, concluding that the WWF’s statistics really showed the sustainability of economic growth. I’m not going to repeat the exercise for the 2018 report.
Instead, let’s track the WWF’s Living Planet Index over the years, as published in previous issues of the Living Planet Report. Doing so is very revealing about the reliability of these numbers.
In 1998, the Living Planet Index consisted of the average of indices for forest cover, freshwater biomes and marine biomes. The latter two comprised population data for 158 species for which statistics at more than one point in time could be found. This is an extraordinarily low hurdle for which data to consider reliable enough to include, but include it they did.
By 2000, the forest cover index had been transmuted into a species index, covering temperate and tropical forests. If you’re measuring two different things, you cannot claim there is a trend. If you have eight apples today, and six oranges tomorrow, you cannot conclude that you lost two bananas.
In 2002, the index was still limited to vertebrate species living in forest, freshwater, coastal and marine ecosystems. A total of 694 species were sampled.
The LPI had worsened from a 30% loss since 1970 to a 40% loss since 1970 in the 2004 report. The survey now included 1,145 species, but forest species now morphed into terrestrial species. The minimum number of data points required to determine a long-term trend remained a measly two.
By 2006, the number of sampled species increased to 1,313, and the LPI miraculously recovered from a 40% loss since 1970 to a 30% loss. Between 2000 and 2003, the years included in the new report, the animal planet must have enjoyed a frenzied bout of procreation.
“This global trend suggests that we are degrading natural ecosystems at a rate unprecedented in human history,” the authors wrote, failing to explain why the rate was exactly precedented in 1998, and was worse in 2000, 2002 and 2004.
For several years, covering the 2008 and 2010 reports, with data from 2003 to 2007, the degradation stagnated at 30%. In 2012, it miraculously improved again, to a mere 28% decline since 1970. By then, the number of species in the index had increased to 2,688, and we had apparently recovered 30% of all the animals that had been declared lost in the 2004 report.
The amazing recovery of the animals came to a grinding halt by 2014, however. Numbers that were stable or improving were obviously not good for fundraising. To jolt people into reaching for their wallets, you need to make them believe that things are getting worse, much worse.
So, in the 2014 report, average animal populations completely collapsed. From a loss compared to the 1970 baseline of only 28% in the 2012 report, suddenly, the average species population loss compared to the 1970 baseline was an astonishing 52%. This is an inexplicable change in just two years, which the WWF attributed to having included more species in their data.
At the time, I noted that even ecologists raised serious concerns, saying that the report’s data quality was often terrible, and it tended to favour populations already in decline, because those are more interesting to science than populations that are thriving.
It only got worse from there. In the 2016 report, the decline from 1970 was 58%, and when the 2018 report was released a couple of weeks ago, we discovered that it had reached 60%.
So from 28% average species population loss in 2012, we went to 60% in 2018. Nobody at the WWF thought that this apparent holocaust, which only appears to have happened in the pages of the Living Planet Report, might cast doubt on the robustness of their vaunted Living Planet Index, and indeed on the quality of all their other published research.
Suspiciously, the WWF’s 2018 chart of the Living Planet Index over time does not record any of these ups and down over the years.
It’s as if the past reports didn’t happen, and all those results were simply adjusted to match the neat curve the authors wanted to present. So much for a “robust index”.
Since we now know how the statistics were manipulated, it is reasonable to suppose that the sudden rapid decline reported from the 2014 report onwards is a statistical artifact, and not at all real.
There are other indications that the WFF is playing fast and loose with graphs and statistics.
On pp24-25, for example, we find a series of charts. On the left hand side, we see socio-economic trends. On the right, we see trends in “earth systems”.
Many of the charts are based at zero on the y-axis, as they should be. Generally, they show a sharp rise, particularly during what the WFF calls the “great acceleration” since 1950.
Although the WWF does not remark on these, a few of the charts show a marked s-curve, that is, the rate of growth has slowed down, levelled off, or even become negative.
This is not yet visible to the naked eye in the population chart, although it is happening. Adding the seventh billion to the global population took longer than it did to add the sixth billion. Population growth is slowing down.
This slowing down of growth is most visible in water use, fertiliser consumption, the number of large dams built, methane emissions, domesticated land, stratospheric ozone, and marine fish capture. It is also visible in the terrestrial biosphere degeneration chart noted above, and even surface temperatures show a plateau since 2000, although it is hardly noticeable at the tiny scale the WWF charts are published.
Five years ago, I noted that we appear to have reached “peak farmland”. Although land is still being converted for agriculture in some areas, this is balanced by land being returned to the wild elsewhere. There is no net growth in agricultural land use any more. Since expansion of agriculture, and resultant habitat loss, has traditionally been the greatest source of pressure on animal populations, the WWF really ought to trumpet this great news.
The apparent visual similarity of the WWF charts is intended to suggest a link, that “all of them are interconnected”, as the report says. Apparent correlation is meant to imply causation.
But the tiny scale also conceals that the various growth rates have been wildly different over the last few decades. There is no s-curve in the rise of real GDP, for example, nor in the urban population, nor in the availability of transportation. Unlike the charts mentioned earlier, those charts continue steeply upwards.
Several of the charts would be far less dramatic if they were based at zero, as they should have been. Take the three gases at the top right. This is what those charts should look like.
This is much less dramatic, of course. Not basing charts on zero is the primary means of exaggerating changes in data. By manipulating the scale of the y-axis you can make any change, however small, appear like a steep, dramatic rise. Here’s what the temperature and ocean acidification charts would look like without such manipulation.
Are those increases still significant? They might very well be, but they look a lot less scary when presented properly.
We need healthy ecosystems in order to thrive. We live in the environment, and we grow our food in the environment. The WWF reports this as a revelation:
“The evidence becomes stronger every day that humanity’s survival depends on our natural systems, yet we continue to destroy the health of nature at an alarming rate.”
Yeah, no, they’re stating the blindingly obvious. They follow that by an exaggerated half-truth. As societies grow wealthier, their negative impact on the health of nature declines, and eventually turns positive.
There is no recognition at all of this reality in the WWF’s alarmist report, nor any discussion of how the problem of scarcity is solved by the price mechanism and free markets, and how these principles might be applied to unowned, communally owned or state-owned natural resources.
In assessing the potential harm some of our activities might do to the environment, we need reasoned conclusions from credible data. All the WWF is offering is dodgy statistics and rhetorical hysteria.
That is of no use to anyone, other than activists who want to blame capitalism for all the world’s ills. Giving them lies for ammunition is a disservice to humanity, and to the ecosystems on which it depends. DM
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