Population

[chaggle]

We've been here before. The Royal Society is starting a proper investigation into population growth. Could be interesting, I don't understand why it's taken so long.

http://www.bbc.co.uk/news/10578484

The UK's Royal Society is launching a major study into human population growth and how it may affect social and economic development in coming decades.

The world's population has risen from two billion in 1930 to 6.8 billion now, with nine billion projected by 2050.

The society acknowledges it is delving into a hugely controversial area, but says a comprehensive and scientific review of the evidence is needed.

[Tony Williams]

Because the obvious response is to try to enforce lower birthrates, as in China (and the abandoned attempt in India), and no politician wants to go there.

The best solution is to ensure that girls have equal education opportunities to boys, that contraception is widely (and preferably freely) available and that women have equal property rights and are aided to set up in business. In every society which has achieved true gender equality, birth rates have plummeted. Most women given the opportunity to be something other than a baby factory jump at the chance.

Unfortunately, the number of children already in existence is now so large that a rise to around 9 billion by the middle of this century seems inevitable (barring lethal pandemics of other global disasters), so we'd better plan for that.

[panama]

Malthusian catastrophe any one?

http://en.wikipedia.org/wiki/Malthusian_catastrophe

[wombatwal]

We are in the throes of a General Election at the moment here in Aussie.
This has come up as a small issue.
The current Prime Minister mentioned she wants a smaller Australia in comparison to the previous Prime Minister from the same party that was espousing a large population.
Of course the usual big business lobby are all over this wanting a large population.
This I think will be a bigger issue in future elections.

[chaggle]

We are in the throes of a General Election at the moment here in Aussie.
This has come up as a small issue.
The current Prime Minister mentioned she wants a smaller Australia in comparison to the previous Prime Minister from the same party that was espousing a large population.
Of course the usual big business lobby are all over this wanting a large population.
This I think will be a bigger issue in future elections.

Hi wombatwal - nice to welcome anther Aussie to UK Skeptics.

I might be exhibiting my ignorance here but I would think that due to its large size, small population and relative affluence this would be less of an issue in Australia than in most other countries.

[Tony Williams]

I might be exhibiting my ignorance here but I would think that due to its large size, small population and relative affluence this would be less of an issue in Australia than in most other countries.

Isn't fresh water supply the main limitation?

[chaggle]

Isn't fresh water supply the main limitation?

Looks like it could be a factor

http://www.circleofblue.org/waternews/biggest-dry/

[wombatwal]

Water is a big problem here, or lack of it, is.
Not many people want to live in the central parts of Australia because of the harsh conditions.
We mainly cling to the coastal fringe.
There has been many ideas about greening the centre but generally these ideas have been hair brained.
Like turning the rivers inland. Building massive water pipe lines thousands of kilometres to pipe the water to where it is needed.
We have to learn to live with the country like the Aboriginals did for 50 to 60+ thousand years. We are slowly learning with water saving initiatives mainly in the cities.
The Farmers have a long way to go, particularly the irrigators.

[Harryprice]

Why would anyone want to 'green the centre'? It is stunningly beautiful and a great attraction for tourists. I love deserts!

[ZERO]

Water is a big problem here, or lack of it, is.
Not many people want to live in the central parts of Australia because of the harsh conditions.
We mainly cling to the coastal fringe.
There has been many ideas about greening the centre but generally these ideas have been hair brained.
Like turning the rivers inland. Building massive water pipe lines thousands of kilometres to pipe the water to where it is needed.
We have to learn to live with the country like the Aboriginals did for 50 to 60+ thousand years. We are slowly learning with water saving initiatives mainly in the cities.
The Farmers have a long way to go, particularly the irrigators.

I don't understand why ground water is not used more. It is in a lot of places and generally good quality too.
Instead these irrigation schemes bring in water from else where which percolates down to the water table and raises it. This cause salinity which has rendered thousands of acres unuseable.
Pipelines and turning rivers around are just expensive ways to cause other problems.
Seems crazy to me.

[Tony Williams]

I don't understand why ground water is not used more. It is in a lot of places and generally good quality too.
Instead these irrigation schemes bring in water from else where which percolates down to the water table and raises it. This cause salinity which has rendered thousands of acres unuseable.
Pipelines and turning rivers around are just expensive ways to cause other problems.
Seems crazy to me.

For the use of groundwater to be sustainable, it can only be extracted at the same rate at which it is replenished. Otherwise, the level will drop steadily until there is no more left in that aquifer.

I would assume that any aquifers in central Australia would not be replenished by rainfall or other natural means, so there's no point in extracting the water. If you did, you could create nice green farming areas for a while, but it would all collapse into dust once the water ran out.

[wombatwal]

Why would anyone want to 'green the centre'? It is stunningly beautiful and a great attraction for tourists. I love deserts!

My thinking also. But there are people with different views that would love to open the centre to farming and development.
Water is only a part of the problem. The soils are so ancient and depleted of any nutrients that only very specialised plants can grow.

[wombatwal]

Groundwater is used reasonably extensively across central Australia. There is a massive artesian basin called the Great Artesian Basin it covers 1.7million square kilometres. It is used by graziers to water sheep and cattle. Bores are sunk to gather the water. The water is apparently not suitable for crops because of the dissolved minerals, but ok for stock.

[chaggle]

Wiki entry here

The basin is 3,000 metres (9,800 ft) deep in places and is estimated to contain 64,900 cubic kilometres (15,600 cu mi) of groundwater.

That's bloody hell of a lot of water but it does seem as if even that amount is being depleted much faster than it is being replaced

Water extraction from the GAB is essentially a mining operation, with recharge much less than current extraction rates. In 1915 there were 1,500 bores providing 2,000 megalitres (1,600 acre·ft) of water per day, but today the total output has dropped to 1,500 megalitres (1,200 acre·ft) per day

[ZERO]

For the use of groundwater to be sustainable, it can only be extracted at the same rate at which it is replenished. Otherwise, the level will drop steadily until there is no more left in that aquifer.

I would assume that any aquifers in central Australia would not be replenished by rainfall or other natural means, so there's no point in extracting the water. If you did, you could create nice green farming areas for a while, but it would all collapse into dust once the water ran out.

It is not an all or nothing proposition. Relying solely on ground water would be unsustainable as you say but the current heavy use of imported water is causing salinity. A balance between the two seems like the obvious solution.