[Edwina Lee (OP)]

With humans dominating land eco-systems to such an extent that 98% of animal mass on land (humans, pets, farm animals) are human-related. (source: Population Trust)

It makes sense that humans should regenerate deserts with the help of cheap energy and sea water. A clear application for solar power I think. With more land, we can grow more food, grow more carbon sinks in the form of trees.

The Sahara and Australian deserts are obvious candidates as they are near the sea.

Let's do some calculations to see how practical this is.

[chris]

Happy to consider the calculations, if you have them?

[AndroidNeox]

Transporting desalinated water from sea level to the deserts requires establishing infrastructure. My personal preference would be to make best use of water reaching the deserts.

I have an idea for how to create oases along river beds. My suggestion (for something to try) would be to dig out a basin in a stream bed that gets flooded once per year. Then pour in a silica gel layer. Fill back in with the sand/soil, amended with biochar.

The silica gel could retain moisture for additional months and the biochar retain nutrients for millennia. Maybe chains of oases could add to the ecosystem in a relevant & useful manner.

[Space Flow]

With good statistics available on prevailing wind directions, we could implement a planting program of appropriate species, starting from where the onshore winds cross the coastline. By doing huge mass planting there it would mean those winds kept picking up moisture, and delivering it further inland.
This would be followed up by further planting as new rainfall areas developed.
This would probably work for Australia.
The Sahara is a different story.
The prevailing winds there are blocked by a huge mountain chain. Those winds dump all their moisture on the slopes of those mountains as they climb up and over to blow over the Sahara as bone dry air.
I remember as a younger lad watching every nation capable of it, doing nuclear bomb tests on our planet.
I understood at the time with the cold war that the situation would not be easily changed and they were going to keep testing, no matter what I thought of the situation.
What I couldn't understand is why they couldn't put all those tests to good use by blowing a channel through the mountains and letting the moisture get through to make the Sahara green again.
Yes it may have been a bit radioactive, but imagine the sorts of life it might have produced....

I no longer think that would have been a good idea, but with all this talk of terraforming other planets, I keep thinking, why are we not trying to develop such technology by terraforming inhospitable environments on Earth.
Instead of all the talk and speculation about detrimental large scale effects we may have caused to our life support system (Earth), why are we not thinking about and implementing beneficial large scale effects to our system?

No calculations but hopefully some logic.

[alancalverd]

Why bother? There's plenty of good farmland and productive forest in the world, just too many humans. No effort is required to reduce the human population to a comfortable level, so why mess about with huge engineering projects when we could achieve more by doing nothing?

[Space Flow]

Why bother? There's plenty of good farmland and productive forest in the world, just too many humans. No effort is required to reduce the human population to a comfortable level, so why mess about with huge engineering projects when we could achieve more by doing nothing?

The problem is getting enough Humans to agree to be euthanized for the sake of the planet.
By your statement do I take it you are putting yourself on that list?
And that still doesn't help the rest of us develop Terraforming technology.

[alancalverd]

No need to persuade anyone to do anything. They will eventually die anyway, although euthanasia seems preferable to such geriatric "care" as the Liverpool Pathway that is generally enforced on the elderly in so-called civilised countries. The trick is not to make more babies. If every woman restricted herself to one child, we would have an indefintely sustainable population within 100 years at no cost to anyone.

Civil engineering by nuclear explosive is unlikely to be costeffective. Both US and USSR programs were abandoned in the 1960s over concern with the fallout plumes. However a nuclear reactor powered excavator could almost certainly produce a neat tunnel through a mountain range. All you need to do thereafter is to find a use for salt water in a desert. But a skeptic might say why not leave the water in the sea and eat seafood? With a smaller human population we could live well on fish.

[chiralSPO]

Deserts aren't necessarily degraded or useless. There are many complex and stable desert ecosystems. Also, deserts provide nutrients for the seas (dust from the Sahara provides a lot of minerals to the Atlantic Ocean)

I agree with Alan that converting deserts to agrarian centers won't really fix many problems in the long run. By reducing the global population (I think 3 billion humans is totally reasonable) and improving the efficiency of food, water, energy, and material distribution (for instance, currently less then 50% of the food produced in the world gets eaten), we can have a much more stable and sustainable civilization.

[Space Flow]

Civil engineering by nuclear explosive is unlikely to be costeffective. Both US and USSR programs were abandoned in the 1960s over concern with the fallout plumes. However a nuclear reactor powered excavator could almost certainly produce a neat tunnel through a mountain range. All you need to do thereafter is to find a use for salt water in a desert. But a skeptic might say why not leave the water in the sea and eat seafood?

Alan you misunderstood me. One those were the musings of a very much younger me and I certainly don't hold the same views now.
And two I never intended for sea water to be let through to the Sahara. Just the moisture laden trade winds.
Off course as chiralSPO points out, you would thus destroy existing eco systems and I no longer think we have the absolute right to knowingly plan to do that. That does not stop us from doing exactly that everywhere we go on this planet, but at least so far we have been able to plead ignorance to some degree.
It appears we can destroy the world as long as we can say we didn't know but we can't make a change for the better on purpose because we don't have the right.

Edwina, it would seem that your grand proposal is defeated by logic that is dependent on Humanity agreeing to reduce it's population to about 3 Billion in time to solve all our problems.

And I thought a young teenage me was a dreamer!!! LOL

[alancalverd]

And two I never intended for sea water to be let through to the Sahara. Just the moisture laden trade winds.

The 1962 "Sedan" plowshares shot displaced 12 million tons of earth and created a crater 320 feet (100 m) deep and 1,280 feet (390 m) wide

That was the effect of a 120 kiloton bomb. Imagine the crater inverted, and it would possibly take a couple of hundred feet off Ben Nevis. I don't think the world ever possessed enough nuclear explosive to take 5,000 feet off the top of the entire Atlas range, which is what you would need to do to make a useful dent in the Sahara. And in doing so, of course, you would sterilise the previously fertile strip of north Africa.

Off course as chiralSPO points out, you would thus destroy existing eco systems and I no longer think we have the absolute right to knowingly plan to do that. That does not stop us from doing exactly that everywhere we go on this planet, but at least so far we have been able to plead ignorance to some degree.

No longer justifiable. We have the means at our disposal to change the only parameter that matters - the human population. If we don't, our starving successors will not forgive us.

[Space Flow]

Alan, you have no argument from me on anything you said.
you have to understand that the whole Nuclear thing was the fairly ignorant musings of a 12-13 year old at a time that we would go to bed every night wondering if the world would still exist in the morning. A beautiful sunset would bring up thoughts of I wonder if someone pressed the button. The French were doing continuous tests not far from my Australian home. It was a strange time and to a young teenager continually kept the nuclear arms race close to the surface.
It has nothing to do with what I think now. I am almost 58.
By the same token, I am watching a world today, maybe "world" is too much of a generalization, so a country, (Australia) with a social security system that pays young girls a living away from home allowance, just for running away from home, and pays them extra for every kid they have. And a social attitude, that if you speak out against such things you are branded as inhumane. Personally I think it's inhumane to encourage them to run away from home and then to further encourage them to be single parents to multiple kids that will never be in a position to reach their full potential in life, by offering them money. But I am obviously inhumane.
Having said all that I think you are dreaming to suggest we have the means at our disposal to reduce the Human population.
I sincerely hope I'm wrong.

[alancalverd]

a social security system that pays young girls a living away from home allowance, just for running away from home,

[ A good thing if home was abusive - the usual reason for running away

and pays them extra for every kid they have.

a bad thing under any system.

Having said all that I think you are dreaming to suggest we have the means at our disposal to reduce the Human population.

AFAIK, Australians reproduce pretty much the same way as everyone else. If you keep your knickers on, you won't make babies. Eventually you will die. Then the population will be reduced by 1, without anyone doing anything at all.

My proposal is to give every woman aged 15 - 55 £500 (AU$1000) every 6 months if she isn't pregnant. No child support allowances, maternity leave, etc. and you lose the payment after the first live birth. Overall, this represents a huge saving in health, education and social security costs and encourages girls (a) to save money for a wanted baby (b) to have regular gynae health checks and (c) to establish a stable partnership or accumulate sufficient capital before making babies.

[Space Flow]

A good thing if home was abusive - the usual reason for running away

Again totally agree. And the reason it was set up in the first place.
Unfortunately any system no matter how good the reasons for setting it up in the first place, is then open to abuse. That is the conundrum that we can't seem to find a solution to. How to be fair to those in desperate need to get out of an abusive home, without encouraging the 15 year olds that just simply don't like the home rules.
The second lot seem to far outnumber the first today.
I have a niece who at 14 ran away because her parents objected to her boyfriend and her desire to have him in her bed. She ended up on the street and pregnant (of course). The police have their hands tied by the law and when they were called about my niece, they tracked her down gave her advice on how to get money from social security, and were not allowed to tell the family her whereabouts.
I'm happy to say this was a few years ago and she is now married with a couple of kids and back in the fold. She is one of the lucky ones.

My proposal is to give every woman aged 15 - 55 £500 (AU$1000) every 6 months if she isn't pregnant. No child support allowances, maternity leave, etc. and you lose the payment after the first live birth. Overall, this represents a huge saving in health, education and social security costs and encourages girls (a) to save money for a wanted baby (b) to have regular gynae health checks and (c) to establish a stable partnership or accumulate sufficient capital before making babies.

You have my vote when running for that position on the world council.
A word of warning. Whenever any of our political candidates have taken a hard line towards these subjects, they have consistently lost the election because of the backlash from the various do gooders and the Catholic church. We are not constitutionally a Catholic nation but it's amazing the amount of power they carry anyway.
I hate to say it but we may have to find ways to reclaim those deserts after all.
The numbers will just keep going up.

[alancalverd]

Pretty soon, half of the world will realise the religion of any sort is a Bad Thing, and the perverts who influence the young by threats of bogeymen or promises of infinte sexual pleasure in the afterlife will be discredited for ever, in favour of rational thought. Until then, I guess things will continue to get worse, with good christians murdering doctors or buggering choirboys, and good muslims murdering everyone else. But one day, Joe Public will stop and say "why do we tolerate this fairytale bullshit?" and take arms against superstition and juju. Either that, or we will all die a horrible death from overcrowding or failure to submit to whatever bizarre rituals the last bent mullah demands of us.

[Edwina Lee (OP)]

With 32,400 sq mls (just over 1%) of Australia burnt up from Sep 2019 till 7th Jan 2020, it is now a perfect time to revive this topic.   
Clearly, starting from the coast with solar power to desalinate ocean water and near civilization, a greening of Australia project would have the best starting point. As more & more desertifying land is regenerated, more value is added and more farming land is available by design. And the more carbon absorbing surface is available to reverse global warming.

[Bored chemist]

No effort is required to reduce the human population to a comfortable level,

Citation needed.

[alancalverd]

No effort is required to reduce the human population to a comfortable level,

Citation needed.

Vide supra (replies # 6 and #11)!

Making babies involves effort. Raising children involves effort. So we start by encouraging girls not to make the effort.

Eventually we die, despite the strenuous efforts of benign health legal and religious professionals to keep us alive until our money runs out. Good taste and humanity suggests a little less of such effort might be welcome, and the decriminalisation of assisted suicide is overdue by at least a thousand years, but even without such humanitarian disintervention, we all die eventually.

So with a little less effort, the population will decline.

There are significant short- and long-term economic advantages in reducing the birth rate to half the replacement level, particularly in the UK. Here, the population is roughly 25% under 20 years old, 50% aged 20 - 60, and 25% over 60. Only the 20 - 60 year olds are economically productive, the others being a net drain on personal and central finances and labour resources. If we reduce the under-20 population by half, the "working fraction", the percentage contributing to the economy, increases, and the money spent on perinatal and education services decreases, so we can afford better public services and pensions. Long term, allowing the UK population to drop to about 5 - 10 million would guarantee our descendants a far better and entirely sustainable (zero-carbon) standard of living. At that point (around 100 years from now) you might consider reproducing at replacement level again.

The argument often advanced against the Chinese one-child policy, that "there will be no young to look after the old", doesn't apply in the UK where we devote as much resource to looking after the young as to the old, and a reasonable pension system means that to a large extent the old  (I'm 75) can look after ourselves. A counterexample came from my own experience: a very bright radiotherapy physicist gave birth to twins. Child care would have cost her 90% of her salary, so she gave up working (principally for the old) to raise the kids. Years of expensive education and training down the drain, followed by state aid and more educational and healthcare costs, and in that case a complete shutdown of regional cancer services. Not quite the model of 5-year olds working in subsistence farms and backyard foundries that the critics have in mind!

[Bored chemist]

That's OK.
It seems we already died out.

Except that, in reality, overcoming the innate desire for kids typically takes more effort than having kids.

[alancalverd]

Hence my suggestion of £1000 a year for not being pregnant. Even if the effect is marginal, it will save public money.

[Bored chemist]

So, you can get £1000 without any effort.
Lucky you.