Population is driving climate and jobs
A small cluster of issues drives climate change. We’re used to thinking and talking about carbon emissions and often many of us quit there. Some think, “If only we had a way to reduce emissions, we could solve the problem.” Unfortunately, emissions are not the whole story, they’re more like a chapter in a book. Important but not everything. Solving climate change is like solving a Rubik’s Cube(2 minute video). You have to solve all sides at once in order to have a true solution.
We’ve explored emissions before as well as carbon absorption and peak oil all of which add a dimension to the problem. But until now we haven’t examined population though it is central to the whole discussion. People use resources and the more people there are, the greater the resource use. More people means greater demand for energy as well as things we don’t think enough about like fresh water and farmland. Yet each of these is under increasing strain from a rising population.
At some point we need to discuss Earth’s carrying capacity which, simply put, is the number of any species that the planet can sustainably support indefinitely. The constraints on the carrying capacity include how much of the many resources we can obtain from the natural environment. For instance, food and water are two foundational elements of carrying capacity but so are safety, shelter, jobs, and clothing. Add to this the things that make life worth living such as culture and entertainment, love, esteem and self-actualization which Abraham Maslow documented in his hierarchy of needs.
At some point, all of the basics that make human life possible and worth living come down to the availability of energy because energy can enhance what the natural environment provides as ecosystem services. For instance, with enough energy we can convert ocean water to fresh water to irrigate farmland. Energy helps us plow fields, pump irrigation water, transport goods to market, light homes, offices, and factories, and it can sometimes be used as a substitute for them. All of these things can be considered supply and population creates demand.
Climate change is a by-product of demand because the more people there are the more they need the things that energy plays a role in providing. Today there are 7.7 billion people on the planet and although various estimates place Earth’s carrying capacity for humans at about 10 billion, demographers predict that’s a number we will reach by mid-century. What happens then?
Carrying capacity can change. For instance, human population was stable until the early 19thcentury when it hit one billion for the first time. Despite the fact that there was a great amount of land available for farming at that point, humans didn’t possess very many machines for most things we take for granted like plowing land or travel. They were largely done by muscle and wind power. Fuel was wood and coal use was in its early days, candles illuminated the night unless you were rich enough to afford whale oil for lamps.
When we began tapping vast reserves of fossil fuels like coal and later petroleum to run machines, we were able to save labor in ordinary processes which enabled us to do more with less. Food became more plentiful and jobs in new industries opened up to employ people. Consequently, the carrying capacity of Earth expanded too and so did the population.
Population increases
Global population passed 3 billion in 1960 and near the end of the baby boom in 1961, the US population totaled more than 183 million. This means that in the roughly 50 years since then we’ve added nearly 1 billion people to the planet per decade so a discussion of Earth’s carrying capacity is not an idle exercise.
Unlike in 1800, there is little additional land to farm, few sources of fresh water that have not been tapped, and our sources of fossil fuels are drying up. The US Department of Energy estimates we have a 50-year supply of petroleum (1.687 trillion barrels) and 100 years’ worth of coal (477 billion metric tons) left on earth.
Energy isn’t our biggest concern though. There are multiple proven technologies available and coming to market that derive power from the sun, wind and earth that will satisfy our future needs. Importantly these technologies can scale up to industrial levels and they are outcompeting fossil fuels on price, all necessary conditions for disrupting the fossil fuel paradigm.
It’s something of a race right now between running out of conventional energy sources and reaching completely unsafe levels of carbon in the environment. Even with all the renewable energy coming online though, we still need to be mindful of Earth’s carrying capacity.
A new green revolution?
By the time Earth’s human population reaches 10 billion we will need to have figured out how to grow more food, make more fresh water, and provide other essentials of life that we once looked only to the ecosystem to provide. We’ll also need to devise new solutions to old problems that are still with us though they’ve been dormant for a long time.
One example is food production. After World War Two, Earth witnessed a massive one-time expansion in conventional food production. Farms were industrialized and, in the process, we optimized every part of growing food crops. We fertilized them, ensured abundant water supplies, restricted weeds and other pests, and used hybridized plants that increased yields and resisted disease. In animal husbandry, we did similar things. We hybridized popular food animals such as beef cattle and chickens, fed them antibiotics and hastened their growth cycles so that we could bring them to market as efficiently as possible.
All this wasn’t an unalloyed good. Farm animals lead dismal, crowded, and short lives. The waste from slaughterhouses is sickening, and many countries don’t want anything to do with genetically modified plants. And there are still nearly half of Earth’s population or 3 billion people are chronically near starvationsubsisting on $2.50 per day or less.
We’ll need another agricultural revolution to feed the world at mid-century but we won’t be able to replay the one that took place in the 20thcentury. All of those easier fixes have been absorbed and while there’s lots of talk and some progress in genetically modifying food crops to improve yields, large parts of the planet want nothing to do with that practice.
The next green revolution will likely involve bringing more marginal lands into production through the use of large amounts of irrigation and fertilizers. The technology and know-how are already here but it will take a lot of new energy sources to desalinate sea water or cleanse grey water from urban uses to make water safe enough for irrigation. The same is true for fertilizers. We need to add nitrogen and phosphorus to croplands to ensure acceptable yields and each has to be acquired from the natural world (phosphorus) or synthesized from petroleum by-products or ammonia (nitrogen). We’ll need new energy sources to do all that.
People pressure
Population pressures make themselves felt in most other aspects of life too like housing, transportation and much more. In some extreme past cases, when a population found life too difficult, a wave of migration began that is very hard to control and is often very hard on the migrants. Currently the UN estimatesthat there are 68.5 million forcibly displaced world-wide, equivalent to the population of France.
There are many reasons for deciding to walk away from one’s homeland, often the reasons are political but increasingly they are climate related. The northbound exodus from Central America is an example. Over population, few jobs, and restricted resources have driven gang violence and drug trade causing many people to flee northward to the United States where the reception has been hostile. Coffee farmers in Central America are reporting that it’s increasingly difficult to grow coffee at lower elevations.
Syria is another example. Droughts early in this decade caused the collapse of farming and farmers moved to already crowded cities with few opportunities. The Arab Spring revolt set off a civil war that caused millions of Syrians to attempt to leave the country by sea where many drowned. European governments were ill prepared to handle the wave of refugees which caused instability throughout the region.
Final thoughts
The Club of Rome, a non-profit organization formed in April 1968 to alert the world to the dangers and challenges of overpopulation and resource depletion, published its seminal work, Limits to Growth, in 1978. It was broadly criticized and successfully ignored by those uninterested in bad news, but it was never refuted or disproved, and it has sold more than 12 million copies. Many of its predictions are coming to the forefront now that global population has exceeded 7 billion (and is still rising).
According Limits to Growth, The 30-year Update, based on the Club of Rome’s landmark report and computer models, resource constraints will restrain population growth but not necessarily in a benign way. If we do nothing, sooner or later, resources like food and water will become scarce enough that people will begin fighting over them and it’s not simply poor people living in emerging countries who will do the fighting, as we see today in impoverished parts of North Africa and elsewhere.
We have the tools and know-how to head off a mid-century disaster in the making but it will take time which means we need to get started building new infrastructure to support ecosystem services and converting the economy to renewable power. We’ll need some of that renewable energy to support those services too.
It’s a heavy lift but one that’s within our abilities though it may not be top of mind. As former two-time EPA administrator William Ruckelshaus said in 1989, the move to sustainability,
“[W]ould be a modification of society comparable in scale to only two other changes: the Agricultural Revolution of the late Neolithic and the Industrial Revolution of the past two centuries. Those revolutions were gradual, spontaneous, and largely unconscious. This one will have to be a fully conscious operation, guided by the best foresight that science can provide. … If we actually do it, the undertaking will be absolutely unique in humanity’s stay on the Earth.”
Climate change is the visible portion of a big iceberg. There’s much more at stake than what we’ll drive in 20 years or how long we’ll need to run our air conditioners. The future of our species is at stake because Earth’s carrying capacity is.
