More and more of us are living better than ever before. In most of the world, an expectant mother can be reasonably confident that she will deliver a healthy baby, who will parent the next generation and live long enough to help educate the generation after that. Wars continue, but the all-out disaster of World War II is ancient history for many of us, and a fading memory for the rest. With our accumulated knowledge and wisdom, and the things we’ve built, we have converted a world that might support a few million hunter-gatherers into home for over 7 billion of us, heading for 9 or 10 billion. When problems arise, we usually invent and cooperate to solve them. We have never fully agreed on the purpose of our existence (and we are not likely to agree in the near future!), but if you approve of any form of “The greatest good for the greatest number”, then this really may be the best time in history.
And yet, we can easily believe we are cursed to live in these interesting times, with disasters waiting at every turn. Perhaps a billion or more people—one in six of us—exist in such poverty or violence that they cannot reasonably expect their children to live long and prosper. Various accounting methods suggest that we are using, and often using up, nearly half of everything that the planet makes available to us and to all other species, with rising population and expectations pushing us rapidly towards using 100%.
We have removed perhaps 90% of the large fish from the ocean—we have no idea what a natural ocean ecosystem looks like, because we fished out so many species before scientists learned to really see what is going on. Roughly 1/3 of the land surface not covered by ice sheets is now used for cropland or grazing, with logging extending our impact. Water is essential to us, but in many places a large fraction of the water we use is not being replaced, as we pump it out of old deposits in the ground or melt it from old deposits in glaciers much faster than new rainfall or snowfall supply more. The soil that grows our crops is being washed away far faster than nature can produce more, so farming is becoming more difficult, especially as we use up the “easy” deposits of phosphate for fertilizer.
With human population expected to increase, many of us not getting even the minimum that most civilized people believe is needed for a proper life, and almost everyone hoping to improve their lot, it takes an optimist to believe that the demands on the planet will “only” double. If our use is already approaching half of everything supplied by the Earth, where will the rest come from? And what does our growing use mean for the other species that share the planet with us, and their ecosystems on which we rely?
A pessimist can easily look past our successes in advancing knowledge and skills and infrastructure and healthy people, and see the history of disasters, wars, environmental refugees, starvation and failure. Humanity has more than enough successes to show that we can succeed, but more than enough failures to show that success is far from guaranteed.
If water runs out, we can desalinate and pump. If soil runs out, there are people growing crops hydroponically without soil, or we might dig the dirt out of the reservoirs behind dams and spread it back on the fields while adding key nutrients, much as a home gardener builds raised beds. If phosphate becomes scarce, we can mine lower-grade ores, and use our knowledge of chemistry to enhance them.
But, desalination uses energy, and lots of it. So does building a hydroponic system, or mining a low-grade ore. So do plowing and shipping, heating and cooling, flying and driving, and so many other things we do. We are relying heavily on energy use to solve our problems already, pulling water out of the ground with pumps to grow our crops, digging phosphate with huge shovels and shipping it—often great distances—to the farm fields to be spread by tractors, and much more. And, our energy use is arguably the most unsustainable thing we do. Roughly 85% of the world’s primary energy production today is fossil-fueled, relying on oil, coal and natural gas, with only 15% from nuclear, hydropower, wind, or other sources. We are using the fossil fuels approximately a million times faster than nature saved them for us, and they will run out.
We apply cheap energy to almost all our problems, a “silver bullet” to slay the dragons that trouble us. But, if we continue on our present course, we will run out of silver bullets. Our current energy system cannot last. Worse, the byproducts of that energy system threaten to change the planet in ways that will make our lives much harder—if we burn all of the fossil fuels before we learn how to use new energy sources, we will have greatly increased the difficulty of our education.