Monday, July 02, 2018

What, We're Running Out of Sand?

Apparently the global demand for construction-grade sand has reached the point where gangs now strip paradise islands of their beaches.

Our insatiable appetite for new buildings, roads, coastal defences, glass, fracking, even electronics, threatens the places we are designed by evolution to love most. The world consumes between 30 and 40bn tonnes of building aggregate a year, and half of this is sand. Enough material to build a wall 27m high and 27m wide around the equator. Sand is second only to water as a natural material extracted by humans, and our society is built on it, quite literally. Global production has risen by a quarter in just five years, fuelled by the insatiable demands of China and India for housing and infrastructure. Of the 15 to 20bn tonnes used annually, about half goes into concrete. Our need for concrete is such that we make almost 2 cubic metres worth each year for every man, woman and child on the planet. 
But what of those oceans of sand stretching from the Atlantic to the Persian Gulf – the Sahara and the Arabian Desert? The wrong kind of sand, unfortunately. Wind action in deserts results in rounded grains that are too smooth and too small to bind well in concrete. Builders like angular sand of the kind found on riverbeds. Sand, sand everywhere, nor any grain to use, to paraphrase Coleridge. A textbook example is the Burj Khalifa in Dubai, the world’s tallest skyscraper. Despite being surrounded by sand, it was constructed with concrete incorporating the “right kind of sand” from Australia. Riverbed sand is prized, being of the correct gritty texture and purity, washed clean by running fresh water. Marine sand from the seabed is also used in increasing quantities, but it must be cleansed of salt to avoid metal corrosion in buildings. It all comes at a cost.
The operative words here are the three above, "our insatiable appetite." This sand problem is an apt metaphor for what we're doing with so many natural resources.

For the past forty years and at a steadily worsening rate, man has been consuming the planet's resources, renewable and non-renewable, at levels far beyond the Earth's carrying capacity. We have ventured further and further into what's called "overshoot."  At the moment we would need almost another planet Earth's worth of resources to sustainably meet our needs.

When nature couldn't supply enough we pillaged the planet's reserves. Not enough surface water? Well, there's water down below. Groundwater, in those ancient aquifers. How much water down there? Who knows, who cares? Only now those groundwater reservoirs are being tapped out. Which brings to the forefront the greater problem, our mortal dependence on resources that are becoming exhausted.

We are depleting nature's reserves. It's called "eating our seed corn." You gorge yourselves on that leftover grain in the silos over the winter and then, come spring, you've got nothing to plant. Can you see how that ends? You may, soon enough.

With the benefit of research and analysis, we know - in hindsight, naturally - that Earth has, or rather once had, the ability to carry a human population of three billion people - max. That's three billion based on levels of population, longevity and consumption as that stood in the early 70s. We've more than doubled in number and we've also grown to live longer and consume, per capita, way more. And most of it we've financed on the resource "never, never."

The thing is, we can't stop. It's a dependency as powerful, more powerful, than being addicted to the very worst drugs. Here we are whining about carbon taxes but have you heard anyone talking about how we'll shed five, maybe six billion people - in a hurry? Why so many? This simple graph illustrates our dilemma.

See where the red line, consumption, first crosses the dotted line, carrying capacity?  That was the early 70s when we first reached three billion people. It took 12,000 years of human civilization to reach that intersection.

You'll see what happens to carrying capacity as consumption steadily increases. Carrying capacity degrades. Resources become exhausted. The planet can no longer support as many people as it once could.  And, once consumption can no longer expand it becomes a tail chase. Resources collapse, population and consumption collapse.

The latest estimates I've read hold that today, the Earth's carrying capacity can support no more than two billion people. It was three billion in the early 70s. Less than half a century later, it's just two billion. But wait. Earth's ecological carrying capacity may be starting to tank but we're still increasing, and at a rapid pace, in population and consumption and pollution of all sorts.

The floor is collapsing beneath us but our momentum is still propelling us ever higher, ever bigger, ever more demanding. We'll even pillage tropical islands for their sandy beaches. We'll fish down the food chain, exhausting the best species and settling for the best of what remains, for now. To feed ourselves we'll so overwork our farmland, with increasing applications of chemical fertilizers, insecticides and pesticides, that our agricultural production will collapse within a lifetime. We are literally working the soil to death. The UN Food and Agriculture Organization, echoing a load of research by agronomists, warned we, mankind, have 60 years of harvests left - max.

Look at that graph again. Once this starts, once that dotted line begins to plunge, and it very much has, it becomes a matter of when, not if.

Which brings me to Jared Diamond and the growing number of scientists speaking out with the same message. It's good that we're now talking about climate change. It would be great if we were serious about the problem. We're not. It would be terrific if we summoned up the resolve as a global community to decarbonize our economies and our societies just as rapidly as possible. We're nowhere near that point, not yet. But the message they're now passing to us is that we also have to resolve overpopulation and over-consumption because you can't hope to solve any of these existential challenges unless you solve all of them.

These problems are linked. They all arise out of one thing - our interaction with this extremely finite planet.

The first home I owned was a neat little 1940s bungalow on the west side in a neighbourhood of neat little 1940s bungalows. Two bedroom, one bath, L-shaped living and diningroom, small but functional kitchen. All the houses were really well kept up with lovely gardens. There was a lane out back and each house had a one-car garage. The lots, for Vancouver, were pretty generous - 50 X 110 and that allowed a decent, pleasant backyard, maybe a deck.

Those houses are all gone now. They have made way for what is called the "Vancouver Special." McMansions, lot line to lot line, with a three car garage (some, more) on the lane and more cars lining the street out front. Some of them are occupied, some aren't. Where that lot used to have one car associated with it, sometimes two, there are now four, five, even six cars.

At my birth the Earth's human population was estimated to be 2.5 billion, an all-time record. Now we've blown past 7.5 billion, heading for at least 9 billion and, by some estimates, 12.  Look at that graph again. We're propelling ourselves into overshoot as fast and as far as greed and technology can take us.

We're not done yet, not nearly. Even our own leaders shamelessly, boastfully proclaim their pursuit of perpetual, exponential growth. I suppose they haven't seen that graph. They don't know about overshoot. They didn't get the press release from the UN FAO. They haven't heard what is visible to the naked eye of scientists orbiting Earth on the International Space Station. They don't know that wildlife stocks have declined by more than half over the past four decades or that species are falling extinct at rates estimated to be as much as 1000 times normal. They don't see man's hand on the algae blooms that are choking our lakes and rivers or the coastal dead zones that have increased by a factor of five along our coasts.

You can't think about those things without realizing that pursuit of perpetual, exponential growth in the world as it is today is a crime against humanity. When you run out of stuff, hit resource "walls," it strictly a net sum game after that. You want to grow, somebody else has to shrink and that's truly diabolical when the most affluent, advantaged and wasteful bunch insist on growing and another group, often struggling for survival, have to do with even less. Meh.


Gyor said...

I don't see why they can't come up with a process that modifies desert sands to make it more useful for construction purposes.

The Mound of Sound said...

Perhaps someone could, Gyor, but that's not the point. The sand represents just the latest aspect of our extreme consumption that will wreck our civilization and our societies. We've gone beyond the point of no return.

Anonymous said...

I remember saying that on the comments page a long time ago. Anyong.