Jakarta Is Sinking So Fast, It Could End Up Underwater • Hacker News Board

Re: Jakarta Is Sinking So Fast, It Could End Up Underwater

#111

Post by openasocket » Sun, Dec 24, 2017, 6:23 AM UTC

oldandtired wrote: post #104

openasocket wrote: post #89

Earlier quoted context omitted.

Surface area? Don't you need volume to compute the thermal expansion of the ocean? And you also need the volume of land ice to compute how much might melt... if you want to convince people, you need to do more than just provide four statistics and walk away, you need to show how you use those to compute the level of expansion. Which you haven't done, and I'm 99% sure you can't with just those four numbers.

Surface area by height (1 to 10 metres) is volume. Of course, if one doesn't know that specific idea then one might be stuck. The volume of land ice can be assumed to be sufficient by the scenarios given. As far as ice expansion is concerned, not really relevant for a first approximation for the energy required as it is relatively small.

I mean you need to know the volume of all the water in the ocean. Because as the temperature rises the water expands, which leads to rising sea levels, in addition to the land ice melting.

Re: Jakarta Is Sinking So Fast, It Could End Up Underwater

#112

Post by ajmurmann » Sun, Dec 24, 2017, 6:52 AM UTC

justicezyx wrote: post #22

org3432 wrote: post #12

Earlier quoted context omitted.

Right, it's the corruption and disorganization that's the problem.

Why not blame the socialism?

Yeah, socialism is why Europe is struggling so hard and Bavarian slums look like a hell hole especially compared to the American South.

Re: Jakarta Is Sinking So Fast, It Could End Up Underwater

#113

Post by rsj_hn » Sun, Dec 24, 2017, 7:09 AM UTC

defo_nonconvex wrote: post #54

rsj_hn wrote: post #51

Earlier quoted context omitted.

Ultimately the resources a nation has are the skills of its people and political will. No nations resources are limitless, and the Netherlands has far fewer real resources but much better skills and organizational capabilities. The fact that the Netherlands was a former colonial power doesn't give them any "colony juice" that they can squeeze onto the ground and dams rise up like apple trees. They still have to desig…

Tiny country by land mass maybe, but you know the Dutch East India Company's peak market cap was (inflation-adjusted) 8x10^12 USD, right? If you don't understand the economic impact of early resource abundance, on the ability to construct education systems, universities, professional organizations, infrastructure, and industry, and the 'pool of available talent', then pick up a strategy game. Otherwise just Rand-ian…

Yes, but those nominal amounts are just paper. They are a mechanism to marshall labor, nothing more. They don't correspond to real resources. This is an interesting fallacy -- I remember playing Freeciv, and you would get 1000 coins in the bank, and if you wanted to speed up building of some monument, you just spend the coins and poof, all these things get built, even if you don't have the labor or real resources to do it. The world doesn't work like that. In the real world, if you try to cash out your stock and sell it to build something without the real resources to do it, all that happens is inflation goes up. But a country really only has the labor and land and domestic equipment that it has, and it needs to use that to build all the dams. You can create paper claims valued at hundreds of trillions of dollars if you want, but it doesn't add a single hour of manpower to the country.

Re: Jakarta Is Sinking So Fast, It Could End Up Underwater

#114

Post by stmfreak » Sun, Dec 24, 2017, 7:13 AM UTC

Sea levels have risen a couple millimeters in recent decades, but Jakarta has sunk (according to this article) 14 feet in some areas. But keep on beating that climate change drum!

Sea level rise is global, but it seems wherever we can find sinking cities we get stories about climate change and its relation to rising sea levels.

Re: Jakarta Is Sinking So Fast, It Could End Up Underwater

#115

Post by rsj_hn » Sun, Dec 24, 2017, 7:18 AM UTC

defo_nonconvex wrote: post #54

rsj_hn wrote: post #51

Earlier quoted context omitted.

Ultimately the resources a nation has are the skills of its people and political will. No nations resources are limitless, and the Netherlands has far fewer real resources but much better skills and organizational capabilities. The fact that the Netherlands was a former colonial power doesn't give them any "colony juice" that they can squeeze onto the ground and dams rise up like apple trees. They still have to desig…

Tiny country by land mass maybe, but you know the Dutch East India Company's peak market cap was (inflation-adjusted) 8x10^12 USD, right? If you don't understand the economic impact of early resource abundance, on the ability to construct education systems, universities, professional organizations, infrastructure, and industry, and the 'pool of available talent', then pick up a strategy game. Otherwise just Rand-ian…

You are confusing real and financial resources. Financial resources make sense at the micro level. If I have $100 and you have $10, I can purchase ten times the real resources that you can. But

1) that relative advantage doesn't correspond to an absolute advantage that can be compared across nations. A nation with ten times the market cap of another nation doesn't have 10 times the real resources. It may just have a more developed stock market, or a more financialized economy, or a lower discount rate, or more optimism for future earnings.

2) Neither does market cap mean anything for the nation as a whole. If I have 10 times the wealth of you, I can buy 10 times as many real resources as you can, but together we can still buy only all the real resources available -- when market cap goes up, that doesn't mean more labor is available to purchase, or the nation has more skills or more equipment. It could just mean that there is more optimism about future profits, or a lower discount rate. Market cap doesn't measure the real resources of a nation anyway -- it's a measure of the discounted flow of earnings, but not of the gross value add of the economy. For example, if labor costs go up, profits fall and market cap shrinks. But the real resources do not change -- the labor supply does not shrink. Just the relative price of labor and capital changes. These relative prices can fix the market cap at any point between zero and infinity (exclusive). All by tweaking the risk free borrowing rate, risk premium, and relative prices of labor and capital. You get zero information about the total size of real resources by looking at market cap, all the information is about relative prices for a given set of real resources. The same is true for the total amount of paper claims in an economy -- they give no information on the size of real resources available. They are dominated by relative prices. The proof of this is exactly the fact that the Dutch had such huge market cap when their real resources were so small.

Re: Jakarta Is Sinking So Fast, It Could End Up Underwater

#116

Post by yorwba » Sun, Dec 24, 2017, 7:19 AM UTC

openasocket wrote: post #111

oldandtired wrote: post #104

Earlier quoted context omitted.

Surface area by height (1 to 10 metres) is volume. Of course, if one doesn't know that specific idea then one might be stuck. The volume of land ice can be assumed to be sufficient by the scenarios given. As far as ice expansion is concerned, not really relevant for a first approximation for the energy required as it is relatively small.

I mean you need to know the volume of all the water in the ocean. Because as the temperature rises the water expands, which leads to rising sea levels, in addition to the land ice melting.

To compute the total energy requirements, you don't really need to know the ocean volume, if you are willing to linearly approximate the thermal expansion. If you have less water, the same amount of energy will heat it up to a proportionally higher temperature and correspondingly expand it more, resulting in approximately the same sea level rise.

Obviously this breaks down if you want a more accurate figure, but in that case you also have to account for water shrinking with increasing temperature between 0 °C and 4 °C and so on.

In any case, melting a bunch of ice is a much more energy-efficient way of increasing the volume of liquid water than heating already molten water. The energy required for melting ice is roughly the same as that for heating the water to 80 °C, and 80 °C is not twice as voluminous as 0 °C water.

Re: Jakarta Is Sinking So Fast, It Could End Up Underwater

#117

Post by averagewall » Sun, Dec 24, 2017, 7:45 AM UTC

pje wrote: post #32

sathackr wrote: post #25

So the city is sinking many inches, even feet per year(due to excessive ground water withdrawals). With all the problems the city has, how does climate change(an average sea level rise of a few millimeters per year) even wind up on the reporters radar? I'm no denier, but it aggravates me when someone tries to force a connection to global warming/climate change.

Sea levels are projected to rise from 0.6 to 6 meters this century. [1] So while urban sinking is a much bigger immediate threat, climate change will pose a significant problem in the near future, and—crucially—will affect every coastal city in the world , not just Jakarta. [1]: https://sealevel.nasa.gov/understanding-sea-level/projection...

Actually the lower bound for sea level rise by 2100 predicted by IPCC (0.2 m) is about the same as the natural rate of rise that's been happening since the ice age. So, no, we're not sure climate change will cause significant sea level rise in the near future, although we are pretty sure it'll rise.

Re: Jakarta Is Sinking So Fast, It Could End Up Underwater

#118

Post by frik » Sun, Dec 24, 2017, 7:56 AM UTC

sathackr wrote: post #25

So the city is sinking many inches, even feet per year(due to excessive ground water withdrawals). With all the problems the city has, how does climate change(an average sea level rise of a few millimeters per year) even wind up on the reporters radar? I'm no denier, but it aggravates me when someone tries to force a connection to global warming/climate change.

NYT websites looks ugly on iPad. Doesn't someone test changes these days? All photos of the article have a white 50% transparent rectangle over them, make the photos look like really washed out. Fix your site...

Re: Jakarta Is Sinking So Fast, It Could End Up Underwater

#119

Post by averagewall » Sun, Dec 24, 2017, 7:59 AM UTC

oldandtired wrote: post #104

openasocket wrote: post #89

Earlier quoted context omitted.

Surface area? Don't you need volume to compute the thermal expansion of the ocean? And you also need the volume of land ice to compute how much might melt... if you want to convince people, you need to do more than just provide four statistics and walk away, you need to show how you use those to compute the level of expansion. Which you haven't done, and I'm 99% sure you can't with just those four numbers.

Surface area by height (1 to 10 metres) is volume. Of course, if one doesn't know that specific idea then one might be stuck. The volume of land ice can be assumed to be sufficient by the scenarios given. As far as ice expansion is concerned, not really relevant for a first approximation for the energy required as it is relatively small.

I find that when you're talking about technical things on the internet, it's best to assume the other person knows common knowledge and only doesn't know the idea you're trying to express. It's almost impossible that the GP didn't know V=A*h so pointing it out is more of an insult than anything useful.

Re: Jakarta Is Sinking So Fast, It Could End Up Underwater

#120

Post by Someone » Sun, Dec 24, 2017, 1:58 PM UTC

yanowitz wrote: post #36

Someone wrote: post #18

Earlier quoted context omitted.

Lower GDP generally also means infrastructure works are cheaper. Also, the problem here mostly seems to be not money, but government. As the article states “Nobody here believes in the greater good […] There is no trust”. Short-term, how much more expensive would it be to get clean water from the rivers flowing into Jakarta, instead of from those illegal wells?

Purchasing Power Parity is meant to capture elements like cheaper costs of construction. It gives a real sense of the gap between Indonesia (4th most populous country, with China and India neck-and-neck, followed quite a bit lower by the U.S.) and the Netherlands. Corruption may be a factor too, but you can’t squeeze blood from a stone.

Is meant to, yes, but it doesn’t, because it isn’t possible to capture pricing differences in a single number. In general, cheap to transport durable goods (such as electronics) move easily between countries and, hence, are priced similarly (barring taxes and import tariffs).

Less cheap to transport (e.g. bricks) or less durable (e.g. fruit) goods move less easily, and labor moves least easily.

Consequently, it is way cheaper in poorer countries to have personnel, to pay people for repairing stuff, etc.