mhaze,
>Well yes [Malthus] obviously was wrong. Even the man himself accepted that later in life.
Do you have a reference for that?

>He thought that population would continue to increase but agricultural innovation wouldn't.
No he didn't. His point was that although agricultural innovation would continue to increase food production, the increase would not be exponential.

He was wrong on the details, but his basic point was correct: human populations are capable of exponential growth. If population continues to grow exponentially, it's inevitable the food supply will eventually not be able to keep up. However that's of little relevance today, as humans can now control their fertility, and the population is not growing exponentially.

> Environmentalism is a religion
No it isn't; it's a philosophy.
LEARN THE DIFFERENCE!

Popnperish,

Oh dear. Check out:

https://ourworldindata.org/world-population-growth

Population growth in Europe, Russia, Iran, Japan and other countries is flat-lining, either falling or not rising or barely rising. Birth rates are lower than ever. In China, the annual number of births has reached a plateau and soon will start to slowly fall - population there will rise only because older people live longer, i.e. they do not die as early as before and thereby contribute to the mortality numbers.

If Australia had no immigration, our population would barely rise. Similarly, the US.
Populations in Africa and South America are rising and could double by 2070. But as Jack caldwell pointed out ( https://archive.org/details/demographictrans00cald/page/n1/mode/2up ) the requirements of compulsory education have as massive impact on family size, as children become financial liabilities instead of economic assets. As well, as the years of education for women lengthen, their chances of marrying young diminish and they will tend to have fewer children, if any at all, of only because their chances of reliable employment improve.

So it's possible that the populations of Africa and South America will stabilise by the turn of this century.

Meanwhile, food production techniques are always improving - water use, plant varieties, efficiency of transport and storage (and reduction of wastage).

So, no, the sky is not falling. Be of good cheer :)

Joe

Aidan,

"Do you have a reference for that?"
6th edition of 'Principle of Population'. It wasn't a full throated retreat but he did seek to change the emphasis of his original claims and walk back the certitude of those original claims.

" His point was that although agricultural innovation would continue to increase food production, the increase would not be exponential."

Well that's true - I was just summarising. And he was wrong on both points. Population growth wasn't exponential and agricultural grow was(at times).

"No it [environmentalism] isn't [a religion]; it's a philosophy.
LEARN THE DIFFERENCE!"

No need to yell Aidan. We can all hear you just fine. I do know the difference, although I'd argue one is a subset of t'other. But its because I know the difference that I label environmentalism as a religion.

popnperish,

"We are indeed facing a possible collapse of food supply and in turn human numbers before the middle of this century, largely because there is insufficient land, water and nutrients, and growing conditions made difficult with climate change."

Rubbish. Calories grown per capita (repeat - per capita) have been increasing for 2 centuries. But somehow to the doomsayers the end is always just over the next hill.

Land usage for food growth is decreasing in most locations due to better technology.
Ditto water.
Ditto nutrients.
A warming climate improves food production yields

Mhaze,

In the southern hemisphere, it is mostly water. In the northern hemisphere, it is mostly land. At NH middle latitudes, across northern China, Siberia, Central Asia, northern Europe, the US and Canada, much of that is relatively flat or undulating. Good for grain-growing.

With the blessings of climate change, I wonder how far further north the boundary for grain-growing, and longer growing seasons generally, would be for every C degree rise: fifty kilometres ? One hundred ? And we're talking about, say, twenty thousand kilometres around the hemisphere. So perhaps an extra million, perhaps two million, square kilometres could be opened up to the production of staple food crops by 2100.

Not to mention improved food production, water management, wastage-control, etc. techniques between now and 2100.

If the total human population falls or stabilises by 2100, and food production rises, we could be the very difficult situation where we all have to eat much more than now in order to keep total food supplies down.

Joe

Sorry mhaze, it is you that is wrong about food. Please note the last month's report by the Commission for the Human Future on Food Security in the 21st century:
https://humanfuture.net/sites/default/files/Final%20Report%20on%20Food%20Security.pdf

It warns that The global food system is headed for failure, with potentially catastrophic consequences for all people, nations and for civilisation as a whole.

mhaze and others are assuming that we will always be able to pull the rabbit out of the hat, much like Julian Simon claiming that there would always be enough resources for a growing population for the next 7 billion years (long past the time when our sun will have turned into a red giant and probably expanded beyond Earth's orbit). Even a continued population growth rate of 1% would result in the entire mass of the solar system being turned into a ball of human flesh expanding at the speed of light in a matter of a few thousand years.

Simon's bet with Ehrlich is irrelevant compared to his wider claims.

http://www.mnforsustain.org/partridge_e_j_simon_and_perilous_optimism.htm

As has often been pointed out, in any case, Ehrlich would have won if a different date had been chosen. There are hard physical limits to growth, as explained by the physicist A/Prof. Tom Murphy at the University of California,

http://dothemath.ucsd.edu/2011/07/galactic-scale-energy/

http://dothemath.ucsd.edu/2012/04/economist-meets-physicist/

Aidan may be right that people will come to their senses and stop population growth, but the UN has had to keep revising its projections upward as fertility rates have remained stubbornly high in some countries, mostly in Africa. Australians aren't having too many babies, so our population would stabilise and then even slowly decline with zero net immigration, but we don't have to overpopulate. Our government is doing it for us.