CEPR - Center for Economic and Policy Research


En Español

Em Português

Other Languages

Home Publications Blogs Beat the Press Population Growth Makes It Harder to Address Global Warming

Population Growth Makes It Harder to Address Global Warming

Wednesday, 06 August 2014 04:38

That one should be obvious, but for some reason almost no one ever says it. This is why it is very nice to see Eduardo Porter's piece making the point in the NYT today.

The basic point is probably too simple for economists to understand, but if we have 20 percent fewer people in 2050 than in a baseline scenario, then they all can emit 20 percent more greenhouse gas (GHG) emissions in that year and have the same amount of total emissions. Alternatively, if we have the same amount of per capita emissions, we will have 20 percent less total emissions.Restraining population growth is not going to solve the problem. We have to sharply reduce the amount of GHG emissions per person, but reaching whatever targets we set will be much easier with a smaller population.

It is remarkable how frequently news stories decry evidence of slowing population growth or shrinking populations as implying some sort of catastrophe. This is nonsense. It simply implies a tighter labor market with a rising ratio of capital to labor. In this scenario, workers switch from low productivity jobs (e.g. restaurant work, house cleaning, and retail clerks) to higher productivity jobs. This is a problem for the people who want to hire cheap labor, but will likely be seen as good news by almost everyone else.

Comments (19)Add Comment
Why Sock Puppets Never Talk About a "Loose" Labor Market
written by Last Mover, August 06, 2014 6:24
It simply implies a tighter labor market with a rising ratio of capital to labor.

The sock puppets can't keep this straight with the opposing effects of the Great Recession, the output gap, stagnation and Keynesian spending, where in the short run the ratio of (employed) labor to capital would rise as full employment approaches.

They're concerned about a shrinking labor force, yet when there is more (unemployed) labor than needed from lack of demand, they conveniently switch context and talk about "structural unemployment" or "robots taking jobs".

To be consistent they should be celebrating plenty of labor available (willing to work). But that's too much to comprehend for their tiny minds, brainwashed by the economic predators who own them.

The labor market is never "loose" from lack of demand according the sock puppets. It's always "tight" enough to justify replacing labor with robots, and cause employers hiring problems for lack of sufficient skills for what labor they would hire.

It follows that as population falls the labor force falls and eventually causes a chronic shortage of labor. Look around America. It's happening before your very eyes, in the middle of a "tight" labor market that is never loose.

What Great Recession? What stagnation? What negative externalities like global warming? We're talking population and labor growth here. Econ 101 for sock puppets.
written by JSeydl, August 06, 2014 6:54
It simply implies a tighter labor market with a rising ratio of capital to labor. In this scenario, workers switch from low productivity jobs (e.g. restaurant work, house cleaning, and retail clerks) to higher productivity jobs.

My mind is a little rusty this morning. Can somebody elaborate more on this? A lower labor supply implies a tighter job market and thereby higher wages in existing industries. We then should see rising wages in our current low-wage sectors (restaurant work, house cleaning, and retail clerks). But what causes the shift of workers out of these sectors and into higher-productivity sectors? Don't we need to say something about the skill atainment of labor? Does the lower labor supply cause low-skilled workers to get more education so that they can transition into higher-productivity sectors? How does that work?
The Change in Mainstream Opinion in a Generation
written by sherparick, August 06, 2014 7:53
When I was a young lad, and growing up in the 1950s, 60s, and 70s, population growth and slowing it was one of the elite obsessions of the day. But then it was at least partly a racial fear of huge numbers of yellow, black, and brown people overwhelming the White European world and the use of state coercive authority against the "pohs" to get them to have less babies. But, now, our current elite, having been taught by the childless Rush Blowhard, Faux News, and WSJ editorial page that Environmentalism was secret Marxist-Liberal-Democrat conspiracy to take away their "FREEEDOMMM!!!," now see the need to have plenty of possible workers to compete for every available job on a global basis to depress labor's share of World GDP and increase Capital's share. Also, since population growth is slowing not due to state coercion, but because of women literacy and increase access to contraception and abortion, the wrong kind of "FREEDOM!!!" is being promoted.
2 issues with slowing population growth
written by Dave, August 06, 2014 7:58
I see two issues with slowing population growth that people worry about:

1) Rising costs of things like SS, where a growing population clearly is better than a shrinking population. It is a manageable problem.
2) A lot of people believe that our basic economic models break down in the face of a shrinking population, I think partially because many older models predicted deflation in the face of shrinking demand, and there was a fear of instability. I think sticky prices and wages have alleviated that concern.
The solution to the global warming problem is ...
written by John Puma, August 06, 2014 8:06
both restraining population growth AND sharply reducing the amount of GHG emissions per person.

We are at ?7 billion total population. With our "global economy," no longer it is just the US population that is endlessly "coached" to strive to accelerated consumerism. The US is 5% of the world population but consumes some 20% of the world's resources.

Approximating GHG emissions with consumption, suggests that only 25% of the world's population can consume at this rate without the entire global consumption causing rising emissions.

This is the population of the US and Europe but not much more.

I hope this helps re-focus the need to prioritize population and its growth in the effort to deal with GHG emissions.
written by skeptonomist, August 06, 2014 8:53
The way population trends are discussed in the media you would think there is some kind of new phenomenon or big change which would lead to disaster - this is nonsense. In the first place the ratio of working to total population does not change very much - see the blue curve here:


In the second place the expenses for old people increase but those for young people decrease. In the third place the decrease in population growth rate has been going on for a long time in the US. The red and green curves show the trend in the US for the twentieth century - have the demographic changes which have happened so far led to disaster? Actually there was even more decrease in the rate of population growth in the 19th century. This rate has actually stabilized in the US, so after about 2035 the ratios are projected to remain constant. There is a blip because of the baby boom, but this is small in relation to the overall trend.

I have not looked at the data for China, but obviously the birth rate declined a great deal because of the draconian one-child policy. How exactly has this slowed economic growth in China? Economists used to say that the population growth rate in China was a major barrier to economic growth; it looks like they may have been right.
Burning Fossil Fuel is the Culprit
written by Juan Valdez, August 06, 2014 8:54
You should frame the argument around where the emissions are coming from. The largest greenhouse emissions come from electricity production, transportation and industry -- in that order. If people alter their behavior and go 'green' in these sectors that would make your argument easier to grasp.

Economists have failed miserably to study climate science in any meaningful way. They want to apply the capitalist approach to everything -- build it easier, faster, etc..... which is bad news for the climate. Yep, climate science throws a wrench into economic theories.
Don't forget immigration
written by Mike Brennan, August 06, 2014 9:01
Dean is obviously correct about the connection between population and climate change. And not just climate change: EVERY environmental insult is multiplied by the number of people contributing to it. Lake Erie algae is but one small example.

The population of the United States continues to soar, much of it driven by immigration and the high birth rate of immigrants. Because the U.S. has very high per-capita wealth, each resident of the U.S. has a proportionally large impact on the planet. Like it or not, a growing U.S. population implies a growing environmental burden.

Why, then, do we NEVER discuss the "right" size for the U.S. population when we debate immigration? It simply doesn't happen. We constantly hear about the essential contribution of past immigrants in making us what we are today. Quite true. We talk about justice, opportunity, decency. Very important, to be sure.

But none of that changes the fact that America is full. We need to come to terms with that reality and find other ways to promote economic justice for the world's disadvantaged.

I wrote this back in 2006 when the U.S. population was closing in on 300 million:


According to the United States Census Bureau, the U.S. population now stands at 316 million. Simply stunning. Is anybody paying attention?
Why is a shrinking/stable population something human creativity can't handle?
written by John Wright, August 06, 2014 9:58
The people who optimistically believe human creativity allows the growth of the WW population without limit, ostensibly required to 1. provide more young workers to shore up social services such as SS, 2. care for the elderly, or 3. stimulate demand seem to have an underlying streak of pessimism about the limits of human creativity.

The "must grow the population" crowd is conflicted about human creativity as they seem to believe humans will ALWAYS solve problems related to population growth, human creativity will not be able to solve problems/issues related to population stabilization or population shrinkage.

Given the rapid growth of technology, I believe the world can adapt to a smaller human population base quite nicely.

And AGW may force this with a vengeance.
written by medgeek, August 06, 2014 10:36
"Yep, climate science throws a wrench into economic theories."

Maybe climate science throws a wrench into bad or incomplete economic theories. There's no problem with economics per se when the externalities of environmental damage and the costs to clean up such damage are properly accounted for.
written by AndyFromTucson, August 06, 2014 10:41
The headline should be "it is impossible to address global warming without addressing population growth." As long as the population continues to grow carbon levels will eventually reach the maximum possible level as long as per capita carbon emissions are non zero. Because population growth is geometric, reducing per capita emissions just delays the warming by a few decades at best.
written by Kat, August 06, 2014 11:06
Does the lower labor supply cause low-skilled workers to get more education so that they can transition into higher-productivity sectors? How does that work?

I would think that a tighter supply would allow workers to be more choosy, employers less so. There were many people in the lower employment 90's who could enter the IT field without lots of credentials or experience. Somehow that worked out fine then.
written by Kat, August 06, 2014 11:13
ah- lower "unemployment"
written by Kat, August 06, 2014 11:23
Oh, and on the subject of meaningless numbers how about the growth of CO2 emissions in poor countries (180%) v. wealthy nations (60%)? Sorry, our 60% is more the problem.
Actually, it is more Bangladesh's problem as we await the next major flooding event there.
"The nation always suffers from a shortage of labor"
written by Sandwichman, August 06, 2014 1:30
This from 1939 congressional testimony on Social Security by an economics professor:

"The truth is, of course, that every worker turning out a salable product thereby automatically generates a demand for other products, and thus sets others to work. The Nation always suffers from a shortage, not from a surplus of labor. The more persons working, the greater is the national product, the national income, and the national welfare."
Going a little too fast-- silly math error
written by benamery21, August 06, 2014 5:18
If we have 20% fewer people, they can emit 25% (not 20%) more per capita before reaching the same total emissions.
The I word
written by Juan Deshawn Arafat, August 06, 2014 6:33
It's really amazing Dean that you can write a post like this and not mention the only policy lever the US has to control population growth, which is curbing immigration from low wage (low carbon producing) countries.
@ Sandwichman
written by Larry Signor, August 06, 2014 9:27
Say what? :-)
written by PeonInChief, August 07, 2014 10:43
Kat is right on the issue of getting the necessary skills. In the 1980s I knew someone who was part of a BofA program to train people in IT. They didn't need a bit of computer experience, and were fairly well-paid during their training. And if we really need more skilled workers, the government could make getting those skills cheap and easy. The reality is that we need relatively few well-educated workers for our economy, so we ration education through the marketplace.

Write comment

(Only one link allowed per comment)

This content has been locked. You can no longer post any comments.


Support this blog, donate
Combined Federal Campaign #79613

About Beat the Press

Dean Baker is co-director of the Center for Economic and Policy Research in Washington, D.C. He is the author of several books, his latest being The End of Loser Liberalism: Making Markets Progressive. Read more about Dean.