About 10 days ago Ian Parsons bravely wrote a guest blog on the subject of population. It elicited a lot of comments as raising this subject almost often does.
This post is not a reply to Ian, nor to any of the comments made, but simply comprises some developed thoughts, with some data, on the general subject.
There aren’t too many people in the world, people are quite nice; in fact, some of my best friends are people. But those people are consuming the world’s resouces and emitting pollutants at an unsustainable rate. So, on average, we could solve or reduce those problems by getting rid of some people. If we halved the number of people on Earth that would halve the consumption and the emissions. But that would be a very inefficient way of doing things. Some people are more consuming and more polluting than others.
Let me illustrate that with some numbers although, the numbers will require a bit of explanation so you’ll have to bear with me (or not).
Let’s take global fossil fuel use as the thing we will look at – partly because it is important and partly because there appear to be some fairly good numbers surrounding it.
Starting at a global level, the annual carbon emissions of the Earth through burning fossil fuels are roughly 10 gigatonnes (1 gigatonne = a billion tonnes = 1,000,000,000 tonnes).
The first thing that leaps out at us from this is that the average carbon emissions of the Earth’s 7.5bn people is about 1.3 tonnes of carbon per capita per year.
OK, we have to pause now to explain something else. It’s not my fault, it’s the way that climate scientists do it. There is a difference between a tonne (or an ounce or a packet) of carbon and a tonne (or an ounce or a packet) of carbon dixide. Carbon has an atomic mass of 12 and carbon dioxide has a molecular weight of 44 (12 for the C and twice 16 for the two Os in CO2). Different people, books, websites use different ways of measuring these things so you have to keep an eye on whether you are working in carbon or carbon dioxide (I hope I’ve kept a good enough eye on it).
So, the Earth’s average 1.3 tonnes of carbon per capita per year is the same as an average of just under 5 tonnes of carbon dioxide per capita per year.
Where are you, do you think? according to this information you and I are, on average, a bit, but not a lot, above average at 5.7 tonnes CO2 per capita (look at the right hand column in the table – to make it easier you can order the table by the values in any column by clicking on the arrows in the legend at the top of the column).
Once you’ve got a table like this one (and once you have ordered it by per capita emissions per year) it’s a lot easier to go on an informed witch hunt for the big polluters. It’s quite difficult to start, for me, because before looking it up I had no idea where Palau, with its 65 tonnes CO2 emissions per capita per year actually was. When I discovered it was in the middle of the Pacific (I guessed it might be) and has a population of 25,000 I decided to let them off!
There are some quite striking countries near the top of the tonnes of CO2 per capita per year table though. For example, there are a lot of Middle East countries in about the 20 tonnes per capita per year range. I guess a hot climate, small populations and cheap oil explain that but I’m less inclined to let them off than I am the 25,000 inhabitants of Palau. But wait! Saudi Arabia has 33m people (cf UK 67m) and has a per capita CO2 emission per year of 19.4 tonnes (cf UK of 5.7 tonnes). So there are half as many inhabitants of Saudi than of the UK (Did you know that? Nor me!) but they are each pumping out getting on for four times the emissions each. Well, I didn’t know that. Yet another reason not to sell them arms, if any were needed.
Several of the world’s most populous countries are quite low in the per capita CO2 emissions charts – India, Philippines, Bangladesh. Even China is a bit lower by this measure than I would have thought.
Canada, USA, Russia, Australia and Japan are all populous, developed countries with high emissions per capita where, surely, massive savings could be made.
In contrast, the Democratic Republic of Congo is the 16th most populated country on the planet and yet is bottom of the list in per capita CO2 emissions from fossil fuels per year.
Yes, I know fossil fuel emissions aren’t the whole story but they are quite a bit of it. And I suspect that if we took any other measure of importance we would find a similarly complicated and textured picture.
My point, such as it is, is that the global footprint of the Earth’s human population is massive, and the population is massive, but some people are consuming massively more than others. Even looking at per capita emissions by year by country the figures cover three orders of magnitude – a vast range! To focus on global population is not to focus well enough on global impact.
So if we were looking to halve global emissions then I wouldn’t look for a cull of half the world’s population (not that anyone would ever suggest such a thing, of course) but I’d look to more than halving emissions in the high-emitting countries ranked by their per capita emissions first. There is some interesting information in the first three data columns of this table which show total (not per capita) emissions per year by country – most European countries are reducing their emissions a bit (some a lot) but some of those Middle East countries are really letting rip!
My firm contention is that we could reduce global footprint much more quickly through behavioural change and technology than we could by any methods aimed squarely at bringing population down. Personally speaking I’d love to live on an Earth with half the number of people on it. I can remember such a time in the 1960s and 1970s: there were the Rolling Stones, miniskirts and I added lots of new bird species to my life list every year because I was just getting into birds.
More seriously, I assume that everyone who is bothered about population levels is asking for a cessation into medical research which postpones average age of death for old people in the developed world? It’s not just about birth rate – clearly it’s about death rate too.
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Infant death rates and those of females upto the time they stop reproducing are the most important death rates for a population equation. I was not aware of the Guest blog which I will read when I get the chance.
Generally, my feeling is that the overpopulation argument generally comes from the blame someone else school of thought and actually there are far right wing think-tanks, sponsored by big oil, promoting such ideas.
But Mark is right, children themselves have very little impact on climate, they hate the heating turned up and don’t have any money to frivolously waste on unnecessary journeys. Whereas the old are not only redundant in terms of population equations, but largely those who expend the resources. So in terms of overpopulation blame games and who to cull?????? I’d rather see it as a planning issue actually. Reorganisation around public transport hubs with centralised industry and work. And hike up the price of petrol with tax.
I posted this before but icymi here it is again. This chap has created graphs and animated graphics on many topics relevant here: https://twitter.com/countcarbon
Filbert – I suspect I strongly disagree with you over many things to do with climate change, but Robert Wilson’s graphs and animations are extremely useful and interesting. Many thanks for drawing my attention to them.
Excellent blog, Mark, very helpful data and context.
Re your last point about medicine’s role in increasing longevity, I’ve always thought that for religions – Ok I mean Catholicism – to object to birth control, because it interferes with God’s Purpose (apparently) logically requires equal opposition to death control. There’s a much stronger case that prolonging life after what would otherwise be its natural end is far more intrusive into the Ordained Order Of Things than preventing life starting in the first place. I’ve asked the odd Catholic about this and never had an explanation, but then I strongly suspect they were all Catholics who ignore the edict against birth control anyway so good for them!
And of course, there was the incident at school when a Catholic Priest came in to talk about the Catholic doctrine about contraception. If the almighty and omnipotent God can be excluded by a thin film of rubber, then a) he ain’t almighty and omnipotent and b) I can commit any sin I fancy – mass murder even – provided I do it under a rubber canopy. I remain amazed to this day that the Priest was so ill prepared he didn’t see that question coming from a bunch of teenage boys.
Criticisms of other sects and other religions are available.
Finally – I watched both my father and my brother in law die slowly over 2-3 weeks each in the same year. Both extended deaths were thanks to modern medicine. My siblings and I , as legal next of kin to each other, have all agreed that if it comes to it we all want the machines turned off. When its time its go its time to go. Its extremely important to tell your next of kin of you feel like this, and to write it down, otherwise the doctors may overrule them and keep you alive and suffering against their and your wishes.
Medicine should be about helping people to live better, healthier, happier, and more fulfilling lives, not just the longest one NHS money can buy.
Well done, Mark. Facts & figures used correctly give a balanced perspective on the debate about population size and global warming. Blaming the ‘reproducers’ of the world does not let us off the hook over our polluting lifestyles.
Way too simplistic.
If Mark’s argument is way too simplistic, your response falls some way short of adequately detailing the shortcomings in his analysis. Can you provide some detail on where he is wrong please?
And your previously expressed belief that the World population should be reduced to 1% of its current level is all very well but you have not explained how on earth we can possibly do that without resort to inhumane forced controls. I believe when I asked, you suggested that it only required six generations of everyone restricting themselves to 1 child per couple and that ‘we only had to choose’ which itself seems ‘way too simplistic’ a response. How do you propose to persuade the entire population of the World to make this choice for even one generation let alone six consecutive ones, especially given that the economic value of children will rise strongly in a significantly shrinking population?
I think M. Parry’s comment”way too simplistic” might concern the size of the human population. Mark’s argument is based on a static figure for this, while the situation on the ground shows doubling every 30 – 35 years. If we commit to halving our resource use by 2050,, that will be simply marking time. Climate change will progress at the same rate then as now, for overall, annual CO2 emissions will not change – even though individually they will have halved.
John – that’s quite a guessas to what M. Parry might have meant. But you are wrong in any case in your argument – it depends what type of consumer/emitter doubles in numbers, that was the point of the blog. And we haven’t committed to halving our emissions, even the UK his aiming for zero emissions by then. And that makes a lot more difference than DRC making the same commitment.
If an argument is 3 dimensional, saying it’s not n dimensional enough and then reducing it to 1 dimension doesn’t really cut it. I’m taller than you therefore I am right and your wrong.
Nice blog! The onus is definitely on us to reduce our emissions and resource consumption.
There’s an article in today’s Guardian about increased risk of heart attacks and strokes on high pollution days so burning more fossil fuels might be self-limiting behaviour in population terms.
Yeah, it is all the cyclists bursting a blood vessel over it being harder to run red lights and weave through lanes of traffic when there are more cars on the road. And all the pedestrians getting scared into arrhythmia from the cyclists whizzing by them on the pavements with nary a bell ring to be heard. Typical Guarniad lot, really.
Once you’ve got a table like this one (and once you have ordered it by per capita emissions per year) it’s a lot easier to go on an informed witch hunt for the big polluters. ‘
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Only if you disregard the fact that we have exported our polluting industries to the far east.
De omnibus – good point but not ‘only if’ but ‘whether or not’.
Note last paragraphs in the wiki article with the table: “Territorial-based numbers of emissions do not account for global trade, where emissions may be imported or exported in the form of traded goods. Accordingly, a proportion of the CO2 produced and reported in Asia and Eastern Europe is for the production of goods consumed in Western Europe and North America.
Other powerful, more potent greenhouse gases, including methane, are not included in the data of this article.”
Only a part of the story – much of western consumerism dumped on other people. CCA relies on false accounting.
“go on an informed witch hunt for the big polluters. ”, that would be BP( according to Greenpeace) not little me who actually burns the petrol in my car. So that lets me off the hook.
Doing something about it. The problem is turkeys don’t vote for Christmas. didn’t Macron try putting a tax on fuel and that spawned riots and there are riots in Ecuador etc about the the removal of fuel subsidies.
Answers on the back of an envelope please.
And don’t forget small numbers of people disrupting major transport routes in this country over proposed tax increases on fuel – not so long ago. One of the reasons why I don’t think the current XR approach is justified – because if they can use this tactic then why can’t other groups with small numbers of supporters who believe passionately in their chosen cause. Having said that, the fuel protests undoubtedly worked in blocking the tax increases so perhaps there is no other option…
Very interesting blog, as is usual for this site. I agree with a great dial of what you say (with the possible exception of the last paragraph), but I think there is much that you don’t say that is also relevant.
I think it is a huge mistake to think about population issues just in terms of climate change and carbon emissions. There is no doubt that production and consumption are far more important drivers of climate change than population. However, climate change is not the only process bringing about the destruction of the natural world, and population increase has had a far greater impact in some of the other drivers.
In particular, the rise of agriculture is widely accepted to have been, and globally still is, the main driver of wildlife loss. Most importantly, the problem is not restricted to intensive agriculture in developed nations. Simple production of basic foodstuffs has and still does represent the single largest threat to what remains of the natural world, and is very closely linked to population growth. Of course, the problem is exacerbated by increasing demand for meat and high levels of food waste (which could be addressed by changes in behaviour and technology), but there still remains a relentless exploitation pressure on land and the oceans primarily due to increasing population.
Sometimes I think that climate change is far from the most difficult problem that we face…
Alan – spot on.
And a lot of problems could be sorted out by applying a bit of common sense – something which, alas, the world’s religions in general tend not to facilitate.
If we could only abolish religion… Instead we’ve got people shoving the evangelising religious agenda into works that were explicitly free of religion as part of their set up. Looking at you, Star Trek:STD and Picard, looking at you! At very least we should have codified in the laws about freedom of religion, the right to be from other people’s religion too.
I’d say “first against the wall, come the revolution”, but at this point I have so many people in line for that that I’d have to build new walls. And that is a problem because I have sodding builders in the line too. I have a neighbour who is having work done, and the builder is a council worker who is moonlighting. That means they are in at 6am before nipping off to their work and coming back and working for him from 7pm sometimes until midnight. First against the wall come the revolution, mark my words!
For me, I currently travel 25 miles each way to work and back every day. On the assumption that the density of petrol is around 0.78 g per mL, that is 36 kg per week x about 42 weeks per year, 1.5 tons of carbon since pretty much the whole mass of petrol is carbon. divide that by 12 and X by 44 gives the CO2 output from this activity = 5.54 tons, that equals the rough total CO2 output per capita of a member of the UK population. There it is, a significant factor that could reduce CO2 emissions.
I desperately don’t want to sit in a car for actually and hour and a half every day. I need to seek a job nearer to home that I can either walk to or get the bus.
I quite liked my car commute, when I was able to drive, even when sitting for an hour on the M8. In fact there were days that that was the only time to myself I actually got. The peace and quiet and relief from chatter and hectoring did me good. I’d love to go back to being on a nice long car commute, with the pay level appropriate to sustain it of course.
And that was in a mini-metro too.
George died before the Deviceocene. I like to imagine he would have made some coruscating stuff about it
https://youtu.be/MvgN5gCuLac
The big question is how do we (note: not can but do we) work out how to continue not just with our current standard of living but improving on it with everyone having access to meat meals twice a day and increased personal private mobility options (and long range, not just a mile or two) without increasing emissions and with increased room for nature. That is the aim, not impoverishing and denying ourselves for it.
Because anything other than that only plays into the 0.01%’s plans for a new feudal era of peasants, servants, and a few ultra rich bozos in their gold plated towers.
Erm… reinforced concrete towers! (for when the wheel comes off)!
In a 2016 report by ADAS for the CCC – UK land use projections and the implications for climate change mitigation and adaptation – much was made of the fact that Agriculture had lagged behind other industries in cutting emissions. Well of course it had. The other industries had off-shored large chunks of their emissions whereas food ins and outs were relatively stable. The CCA allowed the off-shoring to disappear, thus presenting a false impression of “progress” under its Alice in Wonderland scheme of Emissions Accounting.
Meanwhile – had the burning desire for more Stuff declined. Of course it had not. Nevertheless bony fingers pointed at farming for not playing its part.
Stakeholders felt quite strongly that the pathway to net zero for agriculture should allow for no export of emissions outside of the UK but the report wobbles in favour of economic performance of the producer countries. So – no ambition to drive down imported food. No point in upsetting trading partners.
And then there is food waste. Eliminate the ~30% waste and it’s nearly equivalent to 50% more production – yet only 4 out of 61614 words in the report were “waste” in the food context. But the report is full of worthy stuff: full of Trade-Offs and Synergies and Pathways and Baselines and Multifunctional yada yada.
Do the easy stuff first – go and Clean Your Room, why don’t you?