Consumption dwarfs population as main global warming threat

A number of commenters suggested I write about population and global warming (see here).  Leading environmental journalist Fred Pearce beat me to the punch with an excellent piece at Yale’s e360 that I almost entirely agree with.

Pierce’s key point is that the rapacious consumption of hydrocarbons and other non-renewable resources practiced by the planet’s wealthiest 10% far outweighs the effects of population growth in developing nations:

It’s over-consumption, not population growth, that is the fundamental problem: By almost any measure, a small portion of the world’s people — those in the affluent, developed world — use up most of the Earth’s resources and produce most of its greenhouse gas emissions.


The world’s richest half-billion people “” that’s about 7 percent of the global population “” are responsible for 50 percent of the world’s carbon dioxide emissions. Meanwhile the poorest 50 percent are responsible for just 7 percent of emissions.

This is not to say that population isn’t important, but mainly that the the population ship has sailed, as it were:

Even if we could today achieve zero population growth, that would barely touch the climate problem “” where we need to cut emissions by 50 to 80 percent by mid-century. Given existing income inequalities, it is inescapable that overconsumption by the rich few is the key problem, rather than overpopulation of the poor many.

To avoid catastrophic global warming impacts, the rich countries need to cut greenhouse gas emissions 80% to 90% by mid-century.   The developing countries (not including China) mostly must slow emissions growth, peak by mid-century, then decline — while ending the vast majority of deforestation by 2020.  China must peak its emissions by 2020 and then reduce after that, first slowly, then quickly by mid-century.

And that brings me to another key point that Pierce makes:

… the number of children born to an average woman around the world has been in decline for half a century now. After peaking at between 5 and 6 per woman, it is now down to 2.6.

This is getting close to the “replacement fertility level” which, after allowing for a natural excess of boys born and women who don’t reach adulthood, is about 2.3. The UN expects global fertility to fall to 1.85 children per woman by mid-century. While a demographic “bulge” of women of child-bearing age keeps the world’s population rising for now, continuing declines in fertility will cause the world’s population to stabilize by mid-century and then probably to begin falling.

Indeed, the only major “developing” country that could pretty much single-handedly finish off the climate — the one whose per capita CO2 emissions have been rising at the most unsustainably fast pace in the past decade by far, which therefore makes it the country whose population growth might have been the biggest source of concern — already has an aggressive population strategy.  The controversial “one child policy” has already helped bring China’s fertility down to 1.7 to 1.8.

For all these reasons, this blog is not going to focus on population.  I have more than enough to write about on the policies and strategies that must be enacted if we are to have a chance at preserving a livable climate — even assuming I knew of and believed in viable population-related strategies, which I don’t.

As always, I welcome your thoughts.

35 Responses to Consumption dwarfs population as main global warming threat

  1. Jeff Hale says:

    I agree that most developing nations’ population growth isn’t a serious climate issue, but I stumbled on this 2007 Slate article in which Daniel Engber argues America’s population growth matters when it comes to climate change.

  2. ken levenson says:

    But doesn’t that just make population growth in the U.S. and other rich countries 10, or more, times important?

  3. Jason Reeves says:

    I’m all in favor of the wealthy of this planet reducing their conspicuous consumption, but the statistics and conclusions in this article are horribly outdated. They are based on the way it used to be in the “third world”, not the way it is now. If the wealthiest 7% of the people cut their consumption by 50%, the rest of the world is waiting in line, eager and able to snap up and consume those resources. And now those countries in Asia and even Africa have the industrial facilities in place to quickly exploit them. Global consumption among ALL economic classes is rising. That’s a problem that will continue even if population growth were to dramatically slow down (which it is not).

    The idea that if the wealthy 7% of the world were to suddenly cut their consumption that those resources and gaseous emissions would simply stop and remain unused is just nonsense. Trying to kid ourselves that increasing population is not the single biggest driving force behind climate change is foolish and does no service to anyone.

    [JR: This is not the blog to attack straw man arguments. Please address your comments to that which has been specifically written about or proposed. Many of your statements are factually inaccurate or outright misrepresentations.]

  4. hapa says:

    more people in the planetary slums means more people totally exposed to the ecological mess we create, so helping other places set up schools, public health, food, livable income distribution, resilient green tech (through open sharing) and so on is part of our job to do

  5. The article linked through Climate, see
    brings reality into the picture.

    A couple of years ago we were hearing that there was “excess liquidity” in the markets. It was then hard to argue that there would not be money to pay for ambitious wind and solar projects, and that a burden on consumers to pay for such would not be tolerable.

    It seemed almost criminally willful to not take part in the Kyoto treaty because it might set back our economy. The excuse that China and India would not slow their progress toward reducing poverty by restricting their development, though it had obvious truth in it, seemed like abdicating of responsibility to lead.

    And all this was in context of massive spending on an unnecessary war.

    How could we expect action from China and India in this context?

    So not much happened except for a lot of talk. Some action started shaping up that would have the effect of shifting away from foreign oil as a fuel source, but that action rarely included measures that would impact life style. A trick was discovered where we could continue to guzzle energy with inefficient cars, by shifting to coal power through electric means. This served to give an appearance that action was being taken.

    There has been no shortage of passion in claiming “greenness” of electric cars as if the hypothetical future of clean power was on the near horizon. Some that should know better are happy to take advantage of the widespread American gullibility in this field.

    The irony seems to be setting in where, even though the average person in USA lives more luxuriously than by average person in countries such as China and India, our economic reality is closing off our options such that our choices are also quite limited.

    In the present reality it seems that people everywhere will have to be offered ways to accomplish CO2 reduction that do not limit life. It is not reasonable to expect people to change basic living patterns. Neither is it reasonable to expect people to take on severe financial burdens.

    Fluorescent light bulbs are good, building insulation has some limited benefit. The big things are motor vehicles and power generation. How can we fix these high waste activities in ways that do not limit life? Perhaps we can figure out practical ways to do this that we can pass on to the developing countries.

  6. paulm says:

    The two are intimately entwined and ultimately result in the same climatic outcome.

  7. MikeB says:

    I think population is still a critical factor on the consequences side, though not as much on the cause/solution side.

    I’m mostly worried about food production. What happens when global food production drops by 10%? 20%? 30%? Currently, we are just barely able to feed 6.5 billion people, but that is as much a distribution problem as a production problem. But if we don’t deal with global warming effectively, I bet we won’t fix food distribution either.

    My prediction is that the richest half-billion people will continue to eat well. However, the remaining 6 billion will suffer massive starvation, and we will very rapidly have less than 6.5 billion people living on this planet. That sudden population drop will almost certainly be accompanied by disease and warfare, and things could get quite ugly.

    Of course, if the world population is closer to 9 billion by the end of the century, and we haven’t stabilized our climate (and thus food production), it’s only going to be worse.

    Since some amount of warming is now inevitable, and a decrease in world food production is also inevitable, I think taking a look at population levels would be a sensible part of our damage mitigation strategy.

  8. Harrier says:

    I’ve begun to wonder if our entire socio-economic system isn’t ultimately the root of our troubles. The current global economic model demands growth, because growth is the only way to counteract the accumulation of crushing debt. Growth in population, growth in carbon emissions, growth in production of both food and goods… the current global system demands that growth continue indefinitely, when the finite resources of our Earth make such a thing impossible.

    The climate crisis, combined with the financial crisis, seem to combine into an indictment of modernity itself.

  9. john says:

    I read recently — can’t remember where or I’d link — that if the world lived at “western” levels, global consumption would be equivalent to more than 30 billion people consuming at today’s average per capita.

    Which means Joe is spot on — consumption (overconsumption) trumps population.

    It might have been work from the the University of British Columbia — Reese et. al. have been doing this kind of analyis for decades, now.

  10. hapa says:

    harrier: “an indictment of modernity itself”

    maybe. personally i think it’s a mismatch between our political arrangements and our scientific understanding; not a modern problem. “economic growth” is in some ways only an institutionalization of big and long-ongoing changes in human development and labor productivity.

  11. Pangolin says:

    I believe it is very important to separate resource conservation from deprivation. If there is to be an increase in global economic output that has to come entirely from resource conservation rather than consumption. If the rich are going to share resources willingly they have to feel they are not accepting undue deprivation in exchange.

    The opposition to climate change action wants people to believe that reducing consumption means shivering in a cold house eating potatoes with no meat or salt. We in turn have to demonstrate repeatedly that we can offer improved quality of life with less resource use.

    The examples are out there. We have electric cargo bikes, light-rail transit, super-insulated houses, green roofs, solar panels, high-speed rail, local farmers markets and green vacations somewhere. The challenge is to get them where everybody can see them and put them within the price range of the resource consuming alternative. The rich aren’t going to turn the heat down and put on a sweater just because we say so. We have to prove our tools work better.

  12. Robert says:

    Communication technologies and the internet are producing a very “flat” world in which anyone with intelligence and motivation can join the excess consumption set. This is why India’s economy is still growing at 6% while the West has stalled. The rich 7% is quite likely to become the rich 50% as the Chinese and Indian populations become fully fledged consumers.

    Bottom line – global population has to be slashed as dramatically as CO2 emissions. If you think this is negotiable nature may disagree with you.

  13. Harrier says:

    The difficulty in talking about population reduction, of course, is convincing people to do it. Which tack is best? An appeal to enlightened self-interest? A modification of existing religious precepts? The simple illustration of overcrowding?

    We are going to get a population reduction this century, of course, as the age of cheap energy ends and climate change begins to affect habitable land and agricultural production. As MikeB says, the cull will come when there’s no longer enough food to go around. Then you’ll get all four horsemen riding across the world. This seems to be the most realistic method of population reduction, sadly.

  14. Gail says:

    Harrier, I doubt it’s an indictment of modernity, since from what I have read, societies have overrun their resources and collectively perished in remote places and the distant past, albeit on a smaller scale. Perhaps an indictment of the short-sightedness of human nature?

  15. Bob Wright says:

    The US has just about the highest CO2 footprint per capita in the world, probably wastes the most energy per capita, has just about the fastest population growth (300 million is just around the corner), and is supposed to be a leader. Finally, the US is a world technological leader.

    Its pretty obvious who should and can make the biggest strides reducing GHG emissions.

  16. Jason Reeves says:

    Sorry if I failed to make myself understood: I am all in favor of the wealthy west drastically slashing its disproportionate emissions quickly. I was simply trying to get my head around the idea the article pushes that continued population growth is somehow a far lesser problem than consumption. Yes, excessive consumption by the top 10% is an issue we can do something about more immediately, but to headline that it “dwarfs population as mail global warming threat” throws me a curve.

    To say “the population ship has sailed” may be factually true, but seems to ignore the additional fact that there is another population ship boarding at the dock right now. The best-case estimates from the UN project 3 billion additional consuming humans born between 2000 and 2040, almost all of them very poor. That’s a 50% increase in the number of consuming human being. Even if the west reduces by half the 50% of global emissions it accounts for by 2030, that gain will be canceled out by all the new consumers being born, even if they are “poor”. Consumption and population are directly linked. They have to be considered together and solved together.

    To suggest that all these additional billions and their parents don’t have to practice CO2 reduction right now and that they can even increase their per capita CO2 emissions for the next 10 or 20 years simply because they are poor may seem ‘fair’ in a moralistic sense, but it doesn’t work in the scientific sense: Such a course can never achieve the goal of stabilizing CO2 levels at under 500 ppm.

    The article seems to acknowledge this obliquely, but for some reason seems to say in the same breath that it’s OK for China and other countries to keep *increasing* per capita emissions until 2020 or beyond simply because they have a lot of poor people.

    Since you claimed I was factually wrong, I feel compelled to add two citations even though this is getting to be a very long comment:

    “Global consumption of livestock products has more than doubled in the past 30 years, driven mainly by substantial growth in meat and dairy consumption in developing nations. In fact, demand for livestock products in developing countries grew THREE TIMES FASTER than in industrialized countries (Delgado et al. 1999; Pinstrup-Andersen et al. 1999:5).”

    Clearly, given the opportunity, people in the developing world did rush to adopt ‘western’ eating habits and there is no reason to believe they haven’t been and won’t continue to adopt other western consumer habits if they can. Why shouldn’t they?

    India, which is on track to become the world’s most populous country in a few more years, is now actively trying to establish its own Detroit Madness and churn out millions of low-cost gas-burning automobiles not for export to the wealthy west, but for consumption by its own internal population:

    Again, here we see a developing country with a massive and rapidly increasing population of impoverished people nonetheless adopting the bad old consumer habits of the west.

    I think it is a mistake to emphasize CO2 reduction over population control. They are both of equal importance in achieving a sustainable planet.

  17. Jesse says:

    I left a similar comment earlier on the original e360 post to snip the neo-Malthusian rhetoric in the bud, but i think some of it bears repeating here. Mostly just to state specifically that discussion of population sneaks into conversations about emissions and global warming in a particularly destructive and distracting way. As the article illustrates, population reduction doesn’t bear that much weight on environmental problems compared to consumption.

    Importantly, the difference is that “population” has no bearing whatsoever on political or economic systems that reinforce the way the greenhouse gases are emitted into the atmosphere. Neglecting these realities or looking at ecological problems as anything but social problem is a dangerous illusion that leads to more injustice and poverty. This author is looking critically at what “sustainability” is actually looking to sustain.

    I guess if you’re invested in inequality, poverty and mass consumption, population is a pretty great way to frame global warming. Might also want to look into bio-fuels. If not, it’s worthwhile not to look at WHO is actually doing the damage more specifically than just “humans” in general. Just because the issue at hand is an environmental one doesn’t mean that blaming “population” or “humans” (as opposed to oil companies, over consumers, input-intensive agriculturalists, etc) makes anymore sense than blaming “population” or “humans” for the War in Iraq, human rights violations in China or genocide in Darfur. There ARE responsible parties with significant agency in all these situations, including global warming, and they SHOULD be held accountable- not guarded by some discourse about overpopulation.

    I think Romm’s choice is to neglect this discourse is apt, well guided and politically progressive.

  18. ecostew says:

    Bob Wright, I agree. And, readers really should read “Collapse” and think about what they are doing and what their communities, counties, states, and federal governments are doing. Yes, the countries/per capita in the 2-3 unit range must engage, but the top few in the 20+ range must get real if AGW is to be mitigated.

  19. Glenn says:

    I agree that it starts with communities, and even in absence of enlightened local elected leadership, people are coming together to look at transitioning to a new paradigm of sustainable living. We have transition towns in Vermont that are looking at data, asking the tough questions, brainstorming, supporting each other and plotting change. This blog is a great foundation and reality check for anyone involved in that work.

  20. EarthFire says:

    I have the perfect solution.

    Bring back polygamy! (For women only).

    The conservative Rs ruined any objective, thoughtful discourse on population when they harped on abortion and wrongly focused public attention on this relatively minor aspect of public policy. Sensible population discourse has been tainted forever — they essentially won this fight. It really, really, really sucks that they did. Good thing most of us recognize that having 6,7,8,9 + kids is an unsustainable practice, esp. if we all do it at roughly the same time in evolutionary history. Exponential growth is bad for most systems in equilibrium, which, we are most definitely not, anymore. For me, human populations are like the bacteria in a very big petri dish, growing wildly, within a closed system, until the natural law of self-limited growth takes over and, well, everyone dies.

    Oh well.

  21. Sasparilla says:

    Gail I think you nailed it there. Joe, great article.

    MikeB, from what I’ve read we can plan on relatively large decreasing of food resources worldwide, from climate change and also human short sightedness (draining aquafers at much faster than replenishment rates for crop irrigation), and while we might get to 8.5 billion people over the next 20 years (basically in the pipeline), I doubt we’ll maintain that for long (as the world’s, particularly Asia’s, fertile river delta’s are inundated with higher sea levels and snow pack/glacier fed rivers become non permanent affairs) and desertification wipes out large swaths of the worlds breadbaskets – and don’t forget the effects on the oceans. Food production is a majorly ugly picture that awaits us no matter what we do. The implications for overall human population numbers by the end of the century are staggeringly bad if we get everything right (don’t ask if we totally blow it – we can’t let that happen) – and the world’s poor will be hit the hardest of course.

    Another cheery thought along this line is that in the last 7 of 8 years the world consumed more grain than it produced (you can only do that for so long) – that is basically a quote from James Lovelock in 2008.

  22. Harrier says:

    Maybe we’ll be able to supplement lost growing areas in the southern hemisphere with more available land and longer growing seasons in the northern hemisphere?

    … of course not. There’s no way we’d be that lucky.

  23. Richard Brenne says:

    Joe, I admire what you do a great deal, and hope to have you join my panels and discussions that have included population and peak oil experts like Al Bartlett and Jim Kunstler in addition to climate experts like Kevin Trenberth and dozens of others.

    We’re always looking for full cost accounting and to factor in all the relevant parts of the equation.

    The consensus we usually reach on my panels is similar to your conclusion, that growth of all kinds is the problem. Bartlett has been a leader in communicating this for 40 years. If we keep population the same and grow per capita consumption, we have a problem with growth that can not and will not be sustained. If we keep per capita consumption the same and grow population, we have the same problem.

    We’re growing both. Many of my panelists feel the world doesn’t have the resources (all fossil fuels, all minerals, topsoil, fish, trees – especially oil and fresh water) to grow the population along UN-projected estimates.

    I’ve had and will continue to have NCAR experts discussing what climate change will mean to agriculture, NOAA experts on fresh water, topsoil, peak oil and peak natural gas (the primary feedstock for fertilizer) experts all discussing what each of these will mean to agricultural productivity. The concerns in each of these areas alone should produce (but of course never have been) front page headlines for a month.

    Combining these concerns is quite sobering. All the mainstream media has done in this regard is to bury the lead, presumably until we start burying each other.

    Keep up the good work, which I support, and I hope to have your contributions to our attempts at full-cost accounting.

  24. Robert says:

    Its not fashionable, but the real problem seems to individual freedom in a global market economy.

    Of course we are going to over-breed, over-consume, over-pollute. It’s what we do. It’s what every species does in the absence of external limits.

    This is why efficient cars, more windfarms and voluntary “green” action by minorities will never acheive anything in isolation. A global political framework is ABSOLUTELY REQUIRED to force people to curb their natural behaviour. We are very rsistant to such a thing so it almost certainly won’t happen.

  25. Gail says:

    Robert, at least Obama gets it, one of my favorite quotes of all time:

  26. Ronald says:

    This article is exactly right.

    A Climate Progress website has to specialize on the problem of Climate. And it’s how much carbon fueled energy that’s being used, not the number of people. Does fewer people help? sure. But If you got people to put to work, have them build noncarbon fueled energy sources, and energy efficient economic processes. That’s the solution.

    I read a book that said that a Human male can live on 1000 square feet, a female can live on 800 square feet of intensive food gardening and a vegen diet. Every person in the United States could be fed if only the land that we have as lawn was intensively food gardened. (including your front and back yards, your companies, golf courses, baseball parks, etc.) That doesn’t mean we have to go to the extreme of plowing up the baseball parks, but that might mean gardening the areas that are now not gardened to grow vegatables for direct human consumption instead of vast fields of grain fed to fatten animals. It’ll let people be healthier too.

    There are ways to solve problems if there is focus on the solution.

    The focus on the climate problem is non and low carbon energy and energy efficiency over carbon based energy.

    A world population of a billion people and uses coal, oil and natural gas as energy sources will have climate problems where a planet with 10 billion people that does not use coal, oil and natural gas will not.


  27. Justus says:

    Joe, I support your decision for a climate blog to focus on climate, but I wanted to address your closing comment – “even assuming I knew of and believed in viable population-related strategies, which I don’t.”

    Every report on the subject I’ve seen has concluded that the surest path to lowering birth rates is improving access to basic education and family planning tools for women. Our support for these policies, in the US, has been inconsistent and often conflicted. But it would be most effective – not to mention the most ethical – approach to lowering global population, while we learn to model resource-efficient prosperity.

  28. Robert says:


    Obama may get it. Many other politicians get it as well. But the problem is can any of them do anything about it and stay elected? Do they even want to? Much easier just to make a few green noises, ignore the problem and collect a big fat pension.

    If some magical technological fix came out of the blue (e.g. a small black box that could deliver limitless electrical power) then the world would stop using fossil fuel overnight. If not then we’re screwed.

  29. Gail says:

    Robert, did you read Obama’s speech? I don’t know IF he can do anything about it given the amount of damage already done, but I do think he wants to. He obviously understands the science, and he’s got two kids. I’m not very optimistic that Obama will be able to thwart the impending disaster because of pubic inertia and the petroleum industry profit motives. But one thought gives me cheer – there is no one on this planet better suited to the task of leading us out of this morass than our President, and aren’t we incredibly lucky that he came along when we have completely run out of time to fool around.

    Isn’t solar limitless electrical power? The problem is, once installed, there’s not much money to be made, and that is why powerful interests resist it.

  30. Robert says:

    Gail, I don’t know if you have looked at the CDIAC site:

    It produces graphs of CO2 emissions (up to 2005) for countries, regions and globally. Emissions are increasing in just about every part of the world, particularly China and India. Liquid fuels in the US is a small part of the overall problem and even if eliminated altogether would not change the overall picture much.

    Can Obama provide global leadership on the CO2? That is what is needed. However, it will be an impossible task unless he can commit the US to a contraction and convergence trajectory that brings them in line with other countries. That will go down a storm with his electorate.

  31. Do we honestly have the luxury of leaving a potential wedge on the table because it isn’t the most important contributor to climate change? And who says “population” is only about rapid growth in the developing world? If discussions of population deflect in any way from consumption as a focus, it is counter-productive. But why are these discussions mutually exclusive and narrowly constructed? We need to move beyond the oversimplification arguments common in the classic UN megaconference divide pointing fingers back and forth saying too much consumption, no, too many people. There are a set of important analytical questions that serious IPCC types are investigating in this realm – why throw it overboard before we even have the results of their research?

  32. Milan says:

    The response to this seems obvious: Population control in the rich world.

  33. Sidharth says:

    Brilliant Figures and excellent post !!!


  34. Thank you for laying this canard to rest. I suspect the obsession with population with respect to climate is a spillover with the (justified) obsession with population with respect to many of the features of Limits to Growth. When you’re talking about overshooting locally-available resources, population is quite relevant.

  35. Rick DeLong says:

    I agree that population is not directly related to climate change and should not be seen as being a synonym or proxy issue for climate change. However, that the two are somehow related is undeniable. The only reason we can have such a large population today is because of the use of fossil fuels in agriculture. It’s possible, maybe even likely, that the Earth would have reached 6.5 billion people in the absence of any fossil fuels, but these sources of cheap energy have allowed food production to skyrocket unsustainably “ahead of time.” Modern agriculture accounts for a large chunk of our total fossil fuel usage, and agricultural land use practices also contribute to the increase in CO2 levels.

    Land use is just as relevant to climate change as the use of fossil fuels in modern transportation and deserves to be discussed in the same breath as climate change as a major emitter of GHG.

    Population growth is to climate change what economic growth is to climate change. It is not THE problem (resource consumption and management is the problem), but it is a kind of underlying paradigm or cultural assumption that is driving consumption of fossil fuels. I would argue that your (Joe’s) philosophical forays into modern economics (e.g. the “Ponzi scheme” topic) could just as easily touch upon population growth. Isn’t it also a Ponzi scheme of sorts? In Michigan, declining population is seen as a threat to county and state budgets because of the diminishing tax base. In Ukraine, Russia, and many other countries, the official press decries population decline as a “grave threat to national security,” and mothers receive substantial government aid for having more children. Population is important to domestic politics (the idea of continual economic growth and an expanding tax base) and geopolitics (competition with other nations; the realization of nationalist agendas). What might be done to redirect states’ incentives toward stabilizing or even lowering population?

    This isn’t directly related to climate change, but then neither is the concept of economic growth.