Let’s assume that that everyone in the world got along peacefully from the beginning of time. Would the earth be over saturated with people? Would we have used up all of our natural resources long ago? I’m thinking of all the people that have been killed in wars, and all the children in their family that would have been born, and so on. How large would our population be today?
Too many parameters. No way to tell how we would have developed, what diseases would have sprung up, what cures might have sprung up, what methods of population control might have sprung up etc. etc. etc. ad infinitum.
First of all, infectious diseases have killed many more people historically than warfare. The Black Death is estimated to have killed 60% of the population of Europe, and it is believed that diseases introduced from Eurasia and Africa killed about 90% of the indigenous population of the Americas after contact in 1492. Wars have never had anything close to that effect (excluding perhaps some deliberate genocides).
Second, there is a positive feedback between population density and disease. Disease can spread more easily in denser populations. So if people weren’t being killed by warfare, an even greater number would have been killed by disease.
Overall I suspect the answer is essentially indistinguishable from the current population. Wars have not killed enough people to make much of a dent in things. For most of history simply getting to be old enough to get killed in a war was the main battle.
You could perhaps argue that there is a roughly constant portion of the population that gets killed in wars. You might then simply add that to our current population. But it won’t make much difference, and indeed with the other variables in our history, is probably in the noise.
My guess is that not much would change if wars didn’t exist. Other factors would prevent overpopulation, mainly famine and disease. For state-level societies at least, the actual demographic impact of wars as compared with other factors is often highly overstated, because wars are dramatic (example: the Spanish Flu epidemic killed at least twice as many people as WW1, and happened at the same time, but gets a lot less press).
Death toll from Flu: 50-100 million
Death toll from WW1: 18 million.
Edit: thoroughly ninja’d!
In addition to disease and famine picking up the slack, there’s also a subtler demographic effect in that resources freed up by the absence of war and competitiveness channeled into peaceful competition would presumably lead to faster economic development, which tends to result in lower birthrates.
Wars cost money, and perhaps money not spent on war would be spent on disease prevention and/or cures?
edited to add: And what Steve MB said.
Interesting.
I didn’t include disease in my original thoughts, but it most certainly is a deciding factor.
Am I wrong to think that the earth itself will control the balance of population by introducing sickness and famine when necessary?
For most of history, this was true even of combatants during war. World War I was the first major war where battle killed more people than disease (about 1/3 killed by disease, 2/3 by battle). Prior to that, disease killed more soldiers than fighting did during wars.
Another point is that warfare has always fueled increases in technology and knowledge. Modern computers got their start in primitive calculating machines used to calculate missile trajectories and to decode cyphers. A lot of medical knowledge along the way has come from desperate doctors experimenting on field casualties in an effort to reduce the death rate of wounded soldiers. Without warfare spurring us on, our knowledge of technology and medicine would not be as advanced as it is now.
The earth won’t do much of anything - it’s a lump of rock. There’s no concept of necessary here - population pressures have impact but there’s no reason to believe that sickness and famine can’t be avoided with better technology and hygiene. There’s no set carrying capacity of the planet, and there’s no actor who can introduce famine or disease into the equation.
Population density, poor hygiene, and other factors can cause diseases that exist to become more prevalent, and evolution can result in variations that are resistant to our current crop of drugs. But no particular directed outcome is necessary or inevitable.
Yes, that is wrong. “The Earth” doesn’t care whether it’s inhabited by 15 billion people or 100 billion jellyfish.
Populations do encounter natural limits to growth, such as starvation when they exceed the amount of food available, or become dense enough for disease to propagate. Human populations have exceeded those limits greatly in the past few centuries through agriculture providing much more food than previously available and by eliminating most infectious diseases as a major cause of mortality.
New infectious diseases are unlikely to again be a major source of mortality on a world-wide basis to the extent that they limit population. Even such diseases as HIV/AIDS have done little to slow population growth worldwide.
At some point, perhaps in this century, we will begin bumping up against the limits of the amount of food that can be produced by the amount of arable land available. (Famines today are mainly produced by failures of food distribution rather than food production.) However, predictions of when that would take place have repeatedly been proved wrong by new innovations in food production.
I think there’s some misconceptions about how lethal even bloody wars like WWII are; the 60 million killed as a result of the war was just 3% of the world’s population in 1945.
So overall, it didn’t do much at all in terms of decreasing population. I don’t doubt that post-war Europe, Russia and Japan were deeply affected in a local sense, but in terms of total human population, the war didn’t do a whole lot.
And the birth rate often goes up after a major war, as witness the Baby Boom in the US.
One should also look at migration patterns because often an area was taken over by another power in a war and that war was often caused by a lack of resources in another area.
This is true in historical periods, because war (well, violent death in any form) makes such a small dent in the vast state-level society populations that existed when people had the tech to write histories.
Interestingly, while murder made a larger impact, percentage-wise, on hunter-gatherers, it wasn’t that much larger.
Where wars and violent death made the greatest impact, was in agricultural or pastoral societies at the tribe/chiefdom level of social evolution: they were (and to the extent they still exist, are) often much more violent, in percentage terms, than either hunter-gatherers, or state-level societies. If you lived in such a society, in some cases, your chances of dying by violence ranged from 10% to over 50%!
Here’s an example of some very interesting stats on the subject:
Note the relatively low level of death by violence in even the most violent state-level society surveyed - 5% for ancient Mexico.
For US in Europe, from 1900-1960, the rate is less than 1% …
If there were no wars, can it be assumed that people would migrate only to places where there were no already established populaces? Short of one country just volunteering to give up their sovereignty to another for the greater good, expansionism would be an alien concept. Smaller countries with tighter borders-not to keep out human invaders, but microscopic ones. Some countries will be successful, some not so much. Those that fail miserably will free up land to expand.
I’ll agree wars cost money, but it’s not like that money disappears. It gets spent on the manufacture of weapons, trucks, ships, uniforms, planes, etc. Which means the money goes into the economy, workers get paid.
I’m not saying the money disappears, but it would be spent on something different. If the current big crisis is not war but disease, might not the big money be concentrated there?
True, but it isn’t an optimally efficient use of money. This issue is often discussed in the context of the “broken window” fallacy:
There are leaps forward in emergency medical treatments during wartime due to necessity (head trauma, pain management, artificial limbs, burns, infection, blood transfusions). These work their way back into general usage fairly quickly so there is already a strong correlation between war and trauma medicine.
Is there any similar correlation between war and contagious diseases? It looks like there were treatments for malaria developed during WWII, for example.