Well, another Earth Day has come and gone. And amid all the articles and blogs, symposia and TV specials about all the things we can do to save the planet, once again it was hard to find any substantive discussion of the single biggest threat to the environment.
Namely, the staggering rise in global population.
That monumental increase - from 2 billion people when my parents were kids, to 3 billion when I was a kid, to nearing 7 billion today - has placed such an unprecedented stress on nature that it threatens to annihilate nature. Or at least us.
And the funny thing is, we never seem to talk about it. Even on Earth Day.
If you doubt that sheer human numbers stand at the root of our environmental mess - from the destruction of rainforests to the collapse of fisheries and coral reefs to the mass extinction of species to global warming itself - just try a simple thought experiment.
Imagine a world just like our present-day world in terms of technology, industry, urbanization, agriculture, pollution, and so on. But this imaginary world has the same population that the real world had just a century ago, in 1909. Namely, 1.6 billion people, instead of the 6.8 we have today. Or about one quarter of today's population.
One quarter of the population translates into a lot of things. For example:
The world would only need one quarter of the farmland we currently use. The rest would go back to the wilderness.
We'd only need to catch one quarter of the fish we currently catch. So no more collapsing fisheries.
We'd only burn one quarter of the fossil fuels we currently burn, and we'd produce only one quarter of the greenhouse gasses we currently emit. So no more global warming. Or Peak Oil.
We'd only dump one quarter of the waste we currently dump into landfills, rivers and oceans.
We'd only pave over one quarter of the land we currently pave over for housing and development.
The list goes on and on.
Now I know what you might be thinking. The problem is not population, it's development and waste and all the evils of our western, nature-abnegating way of life. Case in point: The US has only five percent of the global population but we use 26 percent of the world's energy. So it's not just population.
This is certainly true so far as it goes. It's not just population. The famous I=PAT Equation states that environmental Impact (I) equals Population x Affluence x Technology (PAT). The more Affluence and Technology you have, the greater the impact of Population in terms of consumption and pollution.
But even in the case of woeful consumers and polluters like modern Americans, awash in Affluence and Technology, our thought experiment still holds true. Imagine:
A century ago the US population was 76 million, or one fourth of today's 306 million. So if the US population were still at the 1900 level, then even if Americans were as affluent, technological and wasteful as we currently are, we'd still be only consuming and polluting one quarter of what we consume and pollute today.
And the impact of population can be just as great, or greater, in developing nations, where population increase has been far more pronounced.
Take Brazil and the destruction of the Amazon rain forest. We tend to think of that destruction as a tragic product of environmental recklessness. Yet consider this: One century ago, when the Amazon was still pristine, Brazil's population was a mere 17.5 million. At that level, the temperate areas of Brazil were plenty large enough to accommodate both agriculture and industry without laying a finger on the Amazon.
Today, Brazil's population is 191 million. That's right - eleven times the population of just one century ago. And the Amazon is rapidly disappearing under the onslaught.
Another way to look at the impact of population is to consider the direct results of industrial pollution back in 1909 versus today.
In 1909, industrial pollution was not as bad as it is today - it was far worse. Factories and municipalities dumped deadly effluvia directly into rivers and streams. People everywhere burned filthy coal as their primary fuel. None of the safeguards and regulations on today's pollution were then in place, and certain limited areas - major cities, stockyards, industrial sites - were as filthy as can possibly be imagined.
And yet the rivers and oceans teemed with fish, the wilderness was alive with diverse species, the sky swarmed with birds. Disasters like global warming, oceanic dead zones, rainforest destruction and the mass extinction of species weren't even dreamed of, even in the most industrialized nations.
The reason is simple. The 'inefficiencies' of technology were worse, but the scale of technology was so much smaller - because population was so much smaller - that nature was easily able to absorb the relatively minor assault. Not any more.
The point of my thought experiment isn't to bemoan the fact that the human population isn't at the level of my grandparents' era any longer. Nothing can roll it back to those good old days.
The point is to illustrate that wherever you look, the fundamental issue driving every environmental crisis that threatens the planet today - from mega disasters like global warming to the loss of the fields and woodlands around your home town - is the massive overshoot of the human population.
And nothing we attempt to do to fix those problems, no matter how well meaning and critically important, will succeed if population keeps rising. Basically, everything we discuss on Earth Day amounts to trying to increase 'efficiencies' on the Technology side of the I=PAT equation. Greener energy, better waste disposal, more recycling, fewer greenhouse gasses, etc. All of which is great.
But every time population increases 10%, the efficiencies in T have to increase 10% just to maintain the same impact. And if both Population and Affluence continue to grow - and of course we want Affluence to grow to raise the poor out of poverty - the efficiencies of Technology have to be even greater just to maintain the same level of impact. Thanks to runaway population increase, we're like the Red Queen in Alice in Wonderland - we have to keep running faster and faster just to stay in the same place. And it's not a good place. It's a place that's already destroying the world.
So in the end, the biggest thing the human population can do to save itself and the planet is to stop growing as quickly as possible, and then quickly reduce itself to a sustainable level that prevents us from committing ecocide, or self destruction via ecological suicide.
And yet, with the oceans of ink we spill over the environment - especially on Earth Day, but increasingly all year - a vast silence blankets this topic, the elephant in the room of environmentalism.
As Alice would say, that silence is getting curiouser and curiouser. And as 80 million people join the human race each year, more and more ominous.