The Earth’s carrying capacity for human life is not fixed

This article by Ted Nordhaus was originally published at Aeon and has been republished under Creative Commons.


In a recent Nature Sustainability paper, a team of scientists concluded that the Earth can sustain, at most, only 7 billion people at subsistence levels of consumption (and this June saw us at 7.6 billion). Achieving ‘high life satisfaction’ for everyone, however, would transgress the Earth’s biophysical boundaries, leading to ecological collapse.

Despite its seeming scientific precision, the claim is old, not new – the latest iteration of the longstanding assertion that our population and consumption might soon exceed the Earth’s fixed ‘carrying capacity’. The concept, tellingly, owes its origin to 19th-century shipping, referring to the payload capacities of steam ships. It jumped from the inanimate to the terrestrial at the end of the 19th century, describing the maximum number of livestock or wild game that grassland and rangeland ecosystems could sustain.

Applied to ecology, the concept is problematic. Cargo doesn’t multiply of its own volition. Nor can the capacity of an ecosystem be determined from an engineer’s drawings. Nonetheless, environmental scientists have, for decades, applied the concept to human societies with a claimed precision that belies its nebulous nature.

The ecologist William Vogt was the first to do so in the 1940s, predicting that overuse of agricultural land would lead to soil depletion and then catastrophe. In the late 1960s and early ’70s, Paul Ehrlich focused on food production, and the Club of Rome on material resources; while latter-day environmental scientists and activists have focused more on the effects that pollution and habitat destruction will have on the ‘Earth systems’ that human wellbeing depends upon.

But all hold the same neo-Malthusian view of human fertility and consumption. From the 18th-century arguments of Reverend Thomas Robert Malthus onwards, prophets of environmental doom have imagined that in response to abundance, humans would respond with more – more children and more consumption. Like protozoa or fruit flies, we keep breeding and keep consuming until the resources that allow continuing growth are exhausted.

In reality, human fertility and consumption work nothing like this. Affluence and modernisation bring falling, not rising fertility rates. As our material circumstances improve, we have fewer children, not more. The explosion of human population over the past 200 years has not been a result of rising fertility rates but rather falling mortality rates. With better public health, nutrition, physical infrastructure and public safety we live much longer.

Today, in the United States, Europe, Japan, much of Latin America, even parts of India, fertility rates are below replacement, ie the average number of children born per woman is below two. Much of the rest of the world will likely follow suit over the next few decades. As a result, most demographers project that the human population will peak, and then begin a slow decline, in some cases before the end of this century.

For this reason, today’s warnings of impending ecological collapse mostly focus on rising consumption, not population growth. As many now acknowledge, our social biology might not function like protozoa, but capitalism does. It cannot survive without endless growth of material consumption.

There is no particularly well-established basis for this claim and plenty of evidence to the contrary. The long-term trend in market economies has been towards slower and less resource-intensive growth. Growth in per-capita consumption rises dramatically as people transition from rural agrarian economies to modern industrial economies. But then it tails off. Today, western Europe and the US struggle to maintain 2 per cent annual growth.

The composition of affluent economies changes as well. Manufacturing once accounted for 20 per cent or more of economic output and employment in most developed economies. Today, it is as low as 10 per cent in some, with the vast majority of economic output coming from knowledge and service sectors with significantly lower material and energy intensities.

For decades, each increment of economic growth in developed economies has brought lower resource and energy use than the last. That’s because demand for material goods and services saturates. Few of us need or want to consume more than 3,000 calories or so a day or live in a 5,000-square-foot house. Many Americans prefer to drive SUVs but there is little interest in hauling the kids to soccer practice in a semi-truck. Our appetites for material goods might be prodigious but there is a limit to them.

Even so, that doesn’t necessarily mean we won’t exceed the planet’s carrying capacity. Some environmental scientists claim that we have already surpassed the Earth’s carrying capacity. But this view is deeply ahistorical, assuming carrying capacity to be static.

In fact, we have been engineering our environments to more productively serve human needs for tens of millennia. We cleared forests for grasslands and agriculture. We selected and bred plants and animals that were more nutritious, fertile and abundant. It took six times as much farmland to feed a single person 9,000 years ago, at the dawn of the Neolithic revolution, than it does today, even as almost all of us eat much richer diets. What the palaeoarcheological record strongly suggests is that carrying capacity is not fixed. It is many orders of magnitude greater than it was when we began our journey on this planet.

There is no particular reason to think that we won’t be able to continue to raise carrying capacity further. Nuclear and solar energy are both clearly capable of providing large quantities of energy for large numbers of people without producing much carbon emissions. Modern, intensive agricultural systems are similarly capable of meeting the dietary needs of many more people. A planet with a lot more chickens, corn and nuclear power might not be the idyll that many wish for, but it would clearly be one that would be capable of supporting a lot more people consuming a lot more stuff for a very long time.

Such a future, however, is anathema to many proponents of planetary limits, suggesting hubris of the highest order. But if it is, it is at least born of optimism, of the conviction that with wisdom and ingenuity humans can continue to thrive. Demands to restrict human societies to planetary limits, which environmental scientists and advocates claim to know prospectively, suggest something much darker.

Viewing humans in the same way that we view single-celled organisms or insects risks treating them that way. Malthus argued against Poor Laws, in the belief that they only incentivised the poor to reproduce. Ehrlich argued against food aid for poor countries for similar reasons, and inspired population-control measures of enormous cruelty. Today, demands to impose planetary boundaries globally are couched in redistributive and egalitarian rhetoric, so as to avoid any suggestion that doing so might condemn billions to deep agrarian poverty. But they say little, specifically, about how social engineering of such extraordinary scale would be imposed in a democratic or equitable fashion.

Ultimately, one need not advocate the imposition of pseudo-scientific limits on human societies to believe that many of us would be better off consuming less. Nor must one posit the collapse of human societies to worry deeply that growing human consumption might have terrible consequences for the rest of creation.

But threats of societal collapse, claims that carrying capacity is fixed, and demands for sweeping restrictions on human aspiration are neither scientific nor just. We are not fruit flies, programmed to reproduce until our population collapses. Nor are we cattle, whose numbers must be managed. To understand the human experience on the planet is to understand that we have remade the planet again and again to serve our needs and our dreams. Today, the aspirations of billions depend upon continuing to do just that. May it be so.Aeon counter – do not remove

Ted Nordhaus is an author, environmental policy expert, and the co-founder and executive director of the Breakthrough Institute in California. He is a co-author of An Eco-Modernist Manifesto (2015). He lives in Oakland.


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Jerry Brown is a Prophet

Kiss taking showers and doing laundry at home goodbye and say hello to the world of  regulations designed to micromanaging your life. If you own a business, you already know. If you don’t live in California, you should not think it won’t happen to you, especially if you live in a “blue” state.

New Orleans, Louisiana, 1943. Line at Rationing Board during World War II. Location is the 500 block of Gravier Street. Photograph by John Vachon, via Library of Congress website. Public Domain.

The Progressive majority in California’s legislature and Progressive Governor Jerry Brown know what is best for California. They are sure the state is running out of water and they have the sure-fired cure:

(drum roll)


Senate Bill No. 606, Hertzberg, Water management planning requires the State Water Resources Control Board to adopt long-term standards for the efficient use of water and would establish specified standards for per capita daily indoor urban residential water use.

Assembly Bill 1668 establishes a 55-gallon limits on urban area indoor water use for every urban person in California.

The bill, until January 1, 2025, would establish 55 gallons per capita daily as the standard for indoor residential water use, beginning January 1, 2025, would establish the greater of 52.5 gallons per capita daily or a standard recommended by the department and the board as the standard for indoor residential water use, and beginning January 1, 2030, would establish the greater of 50 gallons per capita daily or a standard recommended by the department and the board as the standard for indoor residential water use. The bill would impose civil liability for a violation of an order or regulation issued pursuant to these provisions, as specified.

Keep in mind an average person uses an average of 90 gallons per day. If you are poor and have older water appliances, you will be hit the hardest by this act. For example, older washers will use 40 gallons per load; one load of clothes in the old washing machine and a three-minute shower and you’ve reached your legal limit for water use for the day. Flushing the toilet will have to wait until tomorrow.

So why is Jerry Brown a prophet (or anyone in the majority in the California legislature, for that matter)? I have been reading (off and on) The Wizard and the Prophet: Two Remarkable Scientists and Their Dueling Visions to Shape Tomorrow’s World by Charles C. Mann. In the book he talks of two very different men: Norman Borlaug (The Wizard) and Carl Vogt (The Prophet). In the Atlantic magazine Mann writes, “Both men thought of themselves as using new scientific knowledge to face a planetary crisis. But that is where the similarity ends. For Borlaug, human ingenuity was the solution to our problems….Vogt’s views were the opposite: The solution, he said, was to use ecological knowledge to get smaller….we may be able to grow enough food, but at the cost of wrecking the world’s ecosystems.”

Wizards see opportunities for using technology to improve humanity’s lot. Prophets see limits to what the planet can sustain and view technology with suspicion.

Prophet Jerry Brown sees California’s Mediterranean climate as limiting. Perhaps we could supply water for people and agriculture but only at the cost of wrecking California’s ecosystems. So if you disobey the almighty God  state, thou shalt be smote but good…daily.

(1) If the violation occurs in a critically dry year immediately preceded by two or more consecutive below normal, dry, or critically dry years or during a period for which the Governor has issued a proclamation of a state of emergency under the California Emergency Services Act (Chapter 7 (commencing with Section 8550) of Division 1 of Title 2 of the Government Code) based on drought conditions, ten thousand dollars ($10,000) for each day in which the violation occurs.

(2) For all violations other than those described in paragraph (1), one thousand dollars ($1,000) for each day in which the violation occurs.

The poor will be hit hardest by this boondoggle. There are better ways to meet California’s water needs other than punishing people.

But then,I am a Wizard living in the land of Prophets.

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California’s Solar Virtue Signal Could Put Housing Out of Reach

The California Energy Commission (CEC) said, “Eureka, we have a refulgently brilliant idea! Let’s require installation of solar panels on new home and low-rise apartment building construction.” Assuming the California Building Standards Commission ratifies the CEC’s proposal (a purported slam-dunk) it will take affect starting January 1, 2020. Less than two years from now.

”The case for this was extremely strong,” [1] CEC commissioner Andrew McAllister said. “[In] California, we do believe in climate change, we do believe in facts … It’s become clear to all of us it’s the right thing to do and that the marketplace is ready.”[2] the UPI reported.

In light of their actions, what the CEC doesn’t believe in are: 1) carbon-free nuclear power plants, 2) consumer choice, or 3) free markets. California has bent to activist pressure and already closed the San Onofre nuclear power plant. Diablo Canyon’s nuclear power plants will close in 2024 and 2025. When the Commish said, ”[T]the marketplace is ready” he didn’t mean a marketplace where you get to choose what you want. He meant a marketplace where you get to pay for what he wants. He meant delicious gooey Crony Capitalism[3], where well-healed, well-connected lobbyists convince bureaucrats to employ the lobby’s preferred remedy.

According to NPR, “Representatives from construction groups, public utilities and solar manufacturers all spoke in support of the plan, which they’ve helped the commission develop for years,” the AP reports. “No industry groups spoke in opposition.” Of course, no groups spoke in opposition: the benefits are concentrated in a few industries and the harm is dispersed among many lower income people and potential homeowners.

The result is Crony Capitalist Pork. Keeping with the meat metaphor, I have no beef with these groups representing their constituents, but I don’t have to like the result. I like markets to sort out such things. Government’s role is to enforce contracts between individuals and protect citizens from crimes against themselves or their property. Beyond that, government’s top-down approach hampers market-driven, bottom-up solutions.

And the bottom line to everyone–but especially the people on the bottom economic rung–is it effectively takes money from their pockets to pay for this scheme. Under this program, everything is going to cost more, especially housing. And not just newly constructed housing. All housing will cost more, including rentals. Look for an upturn in people looking for existing homes because they’ve been priced out of building new. This will force prices up. It is obvious that the CEC does not understand supply and demand curves, incentives, or anything from a basic economics course.

Unlike Classical Liberals, Progressives within government are sure they know not only how to diagnose a market problem, but how to “fix” it with a sure fire prescription. It’s like your nosy neighbor telling you what’s wrong with your life and has the answer to help you. Now imagine she has the power to force you to do it. That is what the CEC has done. As Veronique de Rugy writes on, “These members of the ‘government within the government,’ produce one freedom-restricting, economy-hindering rule after another without much oversight. These rules take many forms, and few even realize they’re in the making—until, that is, they hit you square in the face.”

Photo Credit:

The progressive Los Angeles Times editorial board is all for punching you square in the face. “Of course California should require solar panels on new homes,” An LA Times opinion piece gushed.

The opening paragraph says, getting punched in the face is good for you.

The benefits of solar power are well established. Photovoltaics harness the sun to create electricity, reducing the need for dirtier forms of energy. And residents generate their own power, cutting their utility bills.[4]

There is so much wrong with this paragraph. It begs the question with “The benefits of solar power are well established.” No, the benefits of solar power are not well established. As Michael Shellenberger, President of Environmental Progress notes, If Solar And Wind Are So Cheap, Why Are They Making Electricity So Expensive? “Electricity prices increased 24 percent in California during its solar energy build-out from 2011 to 2017.” And from 2011 to 2017, California, a state whose progressive leadership is committed to renewable energy, saw electricity rates rise to five times higher than the national average. And California is not a one-off in the rate hike department. Germany, Denmark, and Spain already blazed that trail.

The Times editorial goes on to say, The energy commission’s new building standards, which require both solar panels and upgraded insulation, air filters and other efficiency measures, are expected to raise the cost of a new home by $9,500. That’s about half the cost of installing solar systems on existing homes (although tax breaks and other financial incentives can lower the bill). And homes built to the new standards are expected to use 50% as much energy as homes built in 2016 without solar panels….

Yes, the new standards will increase the cost to build homes and apartment complexes. That’s a concern in California, which is in the midst of a housing crisis because it failed for years to build enough homes to keep up with population demand. However, energy-efficiency investments save money over time. The energy commission estimated the new standards will add $40 per month to the average new home mortgage payment, but save $80 per month on heating, cooling and lighting.

The installation cost appears correct though it may turn out to be higher. It is the anticipated savings in energy that they expect that should trouble you. Federal and state governments continue to press for efficiency as a way to save fuel (in order to lower greenhouse gas emissions). And they are usually dead wrong. Too often, government officials do not consider The Energy Efficiency Paradox. Basically, if you save money on one thing, you have money for more of that thing or of something else. If your house is better insulated you might opt to make it cooler or warmer to be more comfortable. You might take a drive to the beach with your savings or buy a bigger car.

And the mandate will be a tax on other rate payers. According to Severin Borenstein,  E.T. Grether Professor of Business Administration and Public Policy at the Haas School of Business writing to Commissioner Weisenmiller, “The savings calculated for the households are based on residential electricity rates that are far above the actual cost of providing incremental energy, so embody a large cross subsidy from other ratepayers. This would be a very expensive way to expand renewables and would not be a cost effective practice…”  In a nutshell, the LA Times editorial board and the CEC cooked the numbers.

The state is spurring innovation and job creation in the clean-energy sector. (California is ranked first in the nation for solar industry jobs at 86,000 — seven times more than the second-ranked state.)

Whenever you hear about government “spurring innovation and job creation” it is to cover the noise of cash being sucked from your bank account. Pork rarely innovates anything. And, the number of jobs is not a good thing. It is the opposite of a good thing for the majority of us—the people paying for electricity and for stuff made with that electricity. The electricity made with solar costs more because it takes forty people in solar to produce the same amount of electricity produced using natural gas. Lots of Jobs per KWH is Bad, not Good. [5]

The Times board sums up their argument with, At the moment, there’s simply no better way to reduce the power demand and greenhouse gas emissions from new residential developments than combining solar power with more energy-efficient designs. The long-term savings, both to homeowners and to the environment, are well worth the up-front cost.

I can think of several reasons for the editorial board lobbing this insane whopper. The possibility that I favor is they have their heads so far up their asses they can’t see more obvious possibilities, such as nuclear.[6] Robert Bryce said in a talk he gave, “There has been a continuing pursuit of density, and, more particularly, power density. And yet now when it comes to energy production, we are told we should go the other way. Toward low power density…. This makes no sense. I’d call it insane but it would be an insult to crazy people.”

In an insult to crazy people, California is requiring a hella-expensive feel good virtue signal and shutting down its power-dense, carbon-free nuclear power plants and replacing them with natural gas and coal (forget the solar panels—they all make power at the same time—driving down the value of the electricity they produce.)




  1. No. He lies like a cheap rug. Cardboard suitcases are stronger than this case’s raison d’être. The case isn’t very strong at all. 
  2. Translation: “The fix is in.”
  3. Also known as cronyism, venture socialism, corporatism, mercantilism, or just plain horse droppings. “Unlike in a free market capitalist system, under crony capitalism it is often more profitable for businesses to spend resources lobbying legislators for handouts in the form of grants, loans, or tax advantages, and protections against competition in order to increase their profits.  In turn, the government’s willingness to hand out special privileges promotes the politically well-connected rather than those who seek to earn the preference of investors and consumers based on merit. The gains of such activities usually accrue to the businesses and politicians involved at the expense of consumers and taxpayers.”
  4. See Footnote 1
  5. Imagine going to Burger King for dinner and, by law, each BK must employ 40 times the people it would normally at $15 per hour to make your meal. The result is one hellaciously expensive burger.
  6. “Of all ignorance, the ignorance of the educated is the most dangerous. Not only are educated people likely to have more influence, they are the last people to suspect that they don’t know what they are talking about when they go outside their narrow fields.”- Thomas Sowell

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