Planetary boundaries tipping points

Raining again in the Delta.  A crew of four from Meadowcreek have come down to get the Delta outpost in shape for the winter.  Rain is an impediment.  That’s putting me in a bad mood.  So I’m going to take it out on journalists.

planetary boundaries flawedIt’s easy to get frustrated at how stupid journalists can be.  Once I thought I might be a journalist.  I liked writing for the high school newspaper and setting type on Friday nights at the old Mexico Ledger.  No one gets to set hot type anymore, but it was sure a revolution in its day and the acme of newspaper technology in the 1960s. To work in a real newspaper alongside all the presses and huge rolls of newsprint was fascinating.  University of Missouri, barely an hour away, had the best journalism school in the country in those days, so my path was clear.   But then reality intruded.

I left the boring small town high school where even the most fascinating subjects were made tedious.  At University I discovered whole new worlds of exciting discoveries awaited me in a multitude of disciplines.  I realized that journalism and debate were my escapes from high school teachers who knew nothing really interesting.  I know that sounds harsh, but it fits the facts.

In my first semester at college, I realized I didn’t need journalism or debate anymore.  More importantly, I realized journalism and law would mean flitting from topic to topic and never understanding, or even being able to study, anything in depth.  Finally, i saw that anyone who goes into journalism or law is unlikely to even want to explore anything in depth.  They like to jump from hot topic to hot topic or well-heeled client to well-heeled client.  So, they are necessarily stupid, lacking in wisdom, and unenlightened.  However, sometimes they surprise me.  Even blind hogs find acorns now and then.

Complementary diversity is a necessary component of ecological resilience.  But journallists like to hype things up, so they call diversity a tipping point.

The tipping point concept, made popular by journalist Malcolm Gladwell, has unfortunately been adopted by scientists who should know better.  The phenomenon Gladwell looks at is universally interesting.  Why do huge changes sometimes come so abruptly?  So the idea of a tipping point, a point beyond which everything changes, is attractive.  It seems to give an explanation for why huge changes happen abruptly.  But it doesn’t.  It just pushed the can down the road at best.  At worst, it obscures reality.  It creates a concept which doesn’t really exist in the world, but can only be inferred after something has happened.

Unfortunately, some who should know better have also adopted this concept.   The Stockholm Resilience Centre (SRC) posits nine “planetary boundaries”, or limits within which the world would have to stay to avoid irreversible environmental damage, the loss of biodiversity is one the list, along with climate change, chemical pollution and land use.

No sensible person disputes that these are bad things, but the tipping point concept is superflous and leads us astray.  The SRC is trying to emphasize that we must change the way we act on this planet.  So I hate to undermine them and I agree with their motivation, but they marshal no evidence that everything will change for the world once some threshold is reached in biodiversity, climate change, chemical pollution, land use, or anything else.  Things will just get worse and worse for all of us, but a better metaphor is the frog in the pan of water.  It gradually warms up and he is cooked before he even knows it.

Let’s take the specific case of biodiversity.  Biodiversity has been understood mostly in terms of the plant and animal species in forests and grasslands and even in agriculture and aquaculture.   One recent study in Tibet focused on  the lesser studied life forms found underground and in the soil.  The journalist reported  that the study showed that soil bacteria and below-ground plant and animal species form an important part of a complex that regulates relations between parts of the ecosystem and how it responds to climate change.

A variety of species living together can lead to stability and efficient recycling of resources in an ecosystem.  Diversity is correlated with resilence. The Tibetan study championed another seemingly useful concept: ecosystem multifunctionality, or EMF, EMF is dependent on biodiversity, as probably seems obvious but wasn’t to this journalist.

Everyone should know that good soils are highly diverse.  “… Pick up a handful of soil and you might find more species there than all of the vertebrates on the planet,” An 1881 paper, “The Formation of Vegetable Mould, Through the Action of Worms, with Observations on Their Habits” by Charles Darwin, shows that diversity and importance of underground species has been long recognized.

There have also been a number of investigations of the effect that climate has on the constituents of an ecosystem, like plants, animals, earthworms, microbes and, hence, the composition of biotic communities. There have even been studies that combine variations of climate with different levels of biodiversity to see how these affect different things, like productivity and resilience and the way the whole, integrated ecosystem works. These studies have made use of changes in climatic conditions as one moves over a landscape–mainly the over-ground plant cover.

The Tibetan study covered 60 sites spanning a gradual variation of climate along alpine grasslands on the Tibetan plateau, spread over nearly 1,000 km, to examine how the EMF, the combined “suite” of environmental functions, behaved under different levels of climate as well as biodiversity, both above and below ground. For quantification of multifunctionality, eight key ecosystem features [(1) over-ground biomass, (2) root biomass, (3) soil organic carbon, (4) soil nitrogen, (5) soil available nitrogen, (6) soil phosphorus, (7) plant nitrogen (nitrogen pools in above ground biomass), and (8) plant phosphorus (phosphorus pools in above ground biomass)] were estimated at each of the sites and averaged. As for the levels of biodiversity at the same sites, estimates were made of the different kinds of (1) bacteria in the soil, (2) an ancient kingdom of cellular organisms called archaea, (3) other animal life in the soil, (4) fungi in the soil and (5) plant species to compute a “soil biodiversity index”. The method used to count the kinds of soil organisms was by analysis of DNA extracted from soil samples.

The levels of multifunctionality at the various sites, as the five elements and the combined index of biodiversity increased or fell, were then analysed statistically. The levels of EMF can be seen to increase with the increase in diversity in soil bacteria and fauna, and total soil biodiversity, while diversity in fungi and archaea do not seem to have an effect.  Sadly the  journalist appears to have read this one paper and, most importantly, takes the paper’s authors interpretations as gospel.

The paper defines EMF as a bunch of physical measurements of plant and soil activity at a particular point in time.  It fails to look at processes or interactions of species.

I can’t imagine a worse way of spending a trip to Tibet than just taking scads of samples from various spots and taking them back to the lab to kill them and break the components down into elements and gross physical measurements.

Non-biotic influences were also assessed by relating EMF levels with rainfall, temperature and the soil moisture, acidity and calcium carbonate (limestone or chalk). The strongest single driver of EMF is soil moisture.

Plant species’ richness and below-ground biodiversity have about an equal effect and the two factors, taken together, accounted for a large fraction, about 45 per cent, of the variation in EMF across sites. The finding is that the abiotic condition of rainfall increaesed soil moisture which increased biodiversity, which, in turn, increased EMF.

“That is important because scientific studies often focus on temperature – not precipitation – when predicting how ecosystems will respond to future changes such as climate change,”

So this study showed rainfall is most crucial to stimulating biodiversity.  Not exactly dificult to believe for anyone who had spent time in the desert and the rainforest.

But it has nothing to do with planetary boundaries or tipping points.  It’s just rehashing and putting new labels on observations people have made for generations.

Anyway, if you got this far, thanks for putting up with my diatribe.  it was cathartic. But the rain hasn’t stopped.  So what shall we do today?


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