The purpose of this paper is to quantify the upper bound of the living standard and to conclude the necessary compromise by physical or mathematical laws, or equivalently, to quantify the effect of trade/military wars between nations, or equivalently, to quantify whether a higher living standard is considered selfish because inevitably someone in the distance must accept some lower living standard.

Following is some observations of the differences in the daily lives between developed and non-developed countries:

- The public toilets are clean, with hot tube water and automatic heat dryer and drinking water available outside. Sweepers use high power air pump to collect rubbish. Pedestrians crossing the street, three cars pipe in line with low speed limit 30 km/h; first car stops and the driver smiles and gestures at pedestrians to cross, the second and third cars stop accordingly, pedestrians cross then all cars restart and accelerate to the original speed. Supermarkets store a lot of food and fruits of all seasons, all cheap and in high quality. - Public toilets are wet and occasionally run out of toilet roll so people better bring some by themselves. Tube water being cold or even public toilets being simply a walled pit, there is no cleaning water for their hands. Sweepers use bamboo broom to sweep, or even no full-time street cleaners. Pedestrian cannot cross the road because three cars drive at fuel-efficient speed at 50 km/h. Although speed limit is 30 km/h, drivers always ignore the laws when the speed limit is below 40 km/h because brake-then-reaccelerate wastes fuel. Pedestrians wait on roadside and cautious of the dirty splash by the cars because cleaning is troublesome. Shops have only seasonal food, less imported and fancy foods.

On two ends of living standards, one is wealthy and polite and the other is nefarious. Once people get used to better places, they will never leave. This tendency is hard coded in our biological survival instinct; tasting the sweet then avoids the bitter, taking the beef once a day then avoids once a month. But what is the cause of different living standard? In fact, these differences in every delicate detail observation correspond to the amount of energy per capita. To have toilets always clean, some sweeper must often stop by for the work. Water cannot be warm without heater and cannot be disinfected without ultra violet device. Speed limit at 30 km/h costs more fuel. Food refrigeration ... etc.

Why not disposable income per person or gross annual income to measure the living standard? there are a few reasons:

1. The life of developed countries may not be in a society allowing private wealth, in some distant planet, it can also be the case to open a connection taps from the "people's commune" when energy is demanded; the laws of physics do not prohibit this possibility.
2. Individuals use their salary to pay for the gas or electricity is just part of the energy consumption, the toilet and street-sweeping usage just mentioned is not counted.
3. Energy and power is a scientific term; 1 joule is the amount of work of acceleration 1 meter/s^2 of 1 kg object for 1 meter. 1 watts is 1 joule per second. Disposable income originated in political economy, being not a scientific term, prevents people from thinking about political and economic and environmental relationships as a whole. Further, it misleads people to the false view and expectation with their respective fiat currency, while summing those expectations throughout the world corresponds to an impossible physical process.
4. Disposable income per person can also be viewed from energy point of view. Roughly speaking, Joe spends 1 dollar on a candy. If it costs 1 dollar to produce this candy and the electricity fee is 3 dollar for one kilo watts hour (3600000 joules ), then behind the scene, the globe overall actually spends 1200000 joules to produce the candy. Because energy conservation, this same amount of energy is what Joe lets out. Increase of 1 dollar in disposable income per person actually stands for increase in 1200000 joules per person to command. If it costs only 0.75 dollar to produce this candy, then the globe as a whole actually spends 900000 joules to produce it, the merchant earns 0.25 dollar and can command 300000 joules in the future which is the real wealth increase of the merchant.
5. Disposable personal income or gross annual income is described in fiat currency so it is easily manipulated and not suitable for scientific rational thinking. For example, two candidates run for an election and both want to do something good for the nation. One claims to fund the work by tax, the other claims no need of the tax and therefore implicitly means to raise the national debt. Just a recent example shows that an irresponsible candidate wins the election because voters are not aware of the whole picture of the economy. But then miserably, the disposable personal income is twisted. For the candy example mentioned above, if the government prints 1 multiple more money, the merchant's 0.25 dollar earning can only commands 150000 joules now and the other 150000 joules of commanding is moved to the government or anyone who gets the new printing money, causing rich people being richer; the increasingly wealth inequality is not the fault of the free capitalism but too many people think this easy way especially when they are angry and in a bad mood about the current unfair situation.
6. Part of gross annual income goes to saving. Normal people will always try to save some money. Equivalently in terms of energy, gross annual income shall be more than energy per capita.

Energy per capita is the measure of living standard and civilization level whose definition is energy input plus domestic produced energy minus energy output minus energy inventory change then divided by the number of population. The access of energy, either stealing or granted or produced locally or trade from surpluses, is never relevant.

The definition of sustainable energy is the energy whose generating method does not change the material composition within a defined boundary. Therefore whether an energy is sustainable is related to the definition of the boundary. For example: If the boundary is the power plant's wall, then petrochemical power plant is sustainable because typical practice of these plants is burning hydrocarbons and getting water and carbon dioxide and energy. Although it will continuously produce water and carbon dioxide but water and carbon dioxide will float to outside of the wall and therefore the material composition is stable within this boundary; on the other hand, if the boundary is defined as Earth atmosphere, then this petrochemical power plant is not sustainable any more. Being non-sustainable energy, energy generation will continually change the material composition of the environment within the boundary, therefore it may in the future cause unexpected harm, such as radioactive material contamination of a nuclear accident or a huge amount of carbon dioxide on climate change. Throughout all this paper, the boundary is defined as the Earth atmosphere so sustainable energy are only solar power ( source from nuclear fusion reactions of the Sun's black body radiation ) and tidal ( source from gravity system of the Earth and the Moon ) and geothermal ( source from internal heat of the Earth ). Solar power can be further classified as: water power ( because some solar energy to move water from the lower to the higher ), wind ( as the atmosphere absorbs some solar energy ), and electro-optical response ( solar panels ).

There is a lot of scientific data. Its summary is that in order to make the economic prosperity of whole mankind in 2050, additional $15 \cdot 10^{12}$ watts of energy is necessary, and no single energy source is enough except petrochemicals and solar; nuclear energy is not enough because the Earth has not so much uranium; hydraulic and wind and tidal are not enough because the source is scarce; geothermal is not enough because a temperature differences is not big enough theoretically to have efficient thermodynamics heat engine. But the demand of petrochemical energy (natural gas and coal) will produce a scary amount of carbon dioxide, even holding annual leakage 1% of carbon dioxide was terrible. So, only solar panel is feasible. The educative part is, viewing these scientific data in the other way, it allows your own settings to conclude the energy per capita level. So you can imagine yourself as the Earth or a country's dictator, without any difficult political problems, to set the energy policy and the living standard under the laws of physics and mathematics.

Since energy usage focuses on solar panels, energy are classified into six classes, three domestic and three foreign: solar panels, sustainable energy other than solar panels, non-sustainable energy. This classification has the following explanation:

1. If exports of energy, input energy is negative. Inventory change is counted into this figure.
2. Foreign energy inevitably involves transport over long distances where the energy is stored in the form of battery or raw materials loaded onto tankers and is shipped to the importer and the importer enables the battery or generate energy by these raw materials. For example, "foreign non-sustainable energy" is basically the ship carrying natural gas or coal or uranium ore, "foreign solar panel" refers to solar power producer stores the energy in hydrogen and oxygen or other compounds after electrolysis, and ship these compounds to the domestic, and then enable these compounds to get energy. Because this process involves conversion into chemical energy form, it would in theory have a thermodynamic efficiency losses, coupled with current technology (far) lower than these thermodynamic efficiency limit, so foreign energy must have a significant energy efficiency loss.
3. Domestic energy only involves transport over short distances, for example, convert the electricity into high voltage power to wire to the destination and then convert back to low voltage, but efficiency loss is smaller than that of the long distance. Even, for example, solar panels are installed on the roof or yard, so-called demanding-end generation which has little transport losses.
4. The Sun is the mother of life. Many biomass can also be considered under this class of solar panels. For example, biodiesel growing a bunch of green plants and turning them into diesel, the planted area is area of solar panels; it involves optical and chemical energy conversion efficiency, though.

But here in this paper the living standard ceiling is the only concern, so these conversion efficiency losses are ignored. Data demonstrated may not be consistent, you are welcomed to add the additional data to your own account. Following argument bases on only arithmetic operations, so please be sure to read on.

The power of the Sun inversely proportional to the square of the distance from the Sun, reaches the Earth with power per square meter 1370 watts. Because the spherical area is 4 x PI x square of the radius of the Earth, and sun exposure area is PI x square of the radius of the Earth, so the surface of the Earth receives an average of only 1/4 solar power, 342.5 watts per square meter. After being scattered and absorbed into the atmosphere, the photon finally touches the solar panel on the ground. Solar panels cannot be installed on the sea because collecting photon usually requires a parabolic reflector mirror or a stable angle toward the Sun. Because the wavelength of the Sun is yellow, according to the photoelectric effect of quantum mechanics, the energy is converted a maximum efficiency of 0.87 of which current technology solar panels achieve 40%. Denote the population by P, each person's square meters to accommodate solar panels by A, other sustainable energy by B x 10^9 w, non-sustainable energy by C x 10^9 w, annual import solar panels by D x 10^16 joules, import annual sustainable energy sources by E x 10^16 Joules, import annual non-sustainable energy by F x 10^16 joules, a year 31557610 second, table columns are as follows:

The Sun power in the distance of the Earth	w / Square meter	1370
Light scattering	The proportion	0.3
Light absorb by the atmosphere	The proportion	0.19
Theory limit of black body radiation from the sun into electrical energy efficiency	The proportion	0.87
Current photoelectric technology relative to the theory of black body radiation conversion efficiency limit	The proportion	**0.4**
Area of solar panels per person	Square meter	**A**
Population	1	**P**
Other sustainable energy	10^9 w	**B**
Non-sustainable energy	10^9 w	**C**
Import annual solar panels	10^16 joules	**D**
Import annual sustainable energy other than solar panels	10^16 joules	**E**
Import annual non-sustainable energy	10^16 joules	**F**
Number of seconds of year	1	31557600
Country area	Square kilometers	G
Solar panels area with respect to total land area ratio	The proportion	**H**
Energy per capita	10^9 joules / year	**I**
Electricity fee	Fiat currency / KWh	**J**
Gross annual income	Fiat currency	**K**
Gross annual income	10^9 joules	**L**

(Non-bold black lettering is for physics setting, bold blue is for the technology improvement, bold red is for your decision, bold black is for the conclusion)

Then:

H cannot be large because it represents the ratio of reduction in services provided by the land. It cannot be greater than 1 because not all land is for solar panels. === Problem 1 ===

If Taiwan uses domestic solar panels as the only energy and solar panels all on people's private house roof, how high is the living standards?

Ans: Assuming that on average each person has roof of 10 square meters ( because of urbanization actually it is very little ), by the formula, the annual energy per capita is 19.18 x 10^9 joules. By the data [Https://goo.gl/HFdhxJ](http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2FHFdhxJ) energy per capita of all countries, it is the living standard of Philippines.

Problem 2

If Taiwan uses domestic solar panels only and solar panels are on people's private land and maintains Japanese living standard, how large private land should be?

Ans: By data [Https://goo.gl/HFdhxJ](http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2FHFdhxJ) energy per capita of Japan is 149.96 x 10^9 joules, by solving the formula, each person's solar panels is 78.17 square meters and this is the least size of private land of each person.

Problem 3

10cb88d78d5d688921d9386209f0623735455d374efb1841e84ab734 If Taiwan uses domestic solar panels and solar panels are on people's private land and maintains Japanese living standard, how to do it?

Ans: According to Problem 2 everyone's private land is at least 78.17 square meters. According to Problem 1 the roof of each person is only 10 square meters. So the only way is to reduce population eight times fewer and solar panel area for each person can be eight times greater accordingly. In other words, population shall decrease from 23 million to 2.87 million.

Problem 4

If besides domestic solar panels Taiwan also considers importing energy and solar panels per person only 10 Square meters and maintains Japan's living standard and does not reduce the population, how much is the input energy?

Ans: $\begin{aligned}H &= A \times P \times G / 10^6\\&= ( ( 1370 \times 0.25 \times ( 1 − 0.3 − 0.19 ) \times 0.87 \times 0.4 \times A \times P + ( B + C ) \times 10^9 ) \times 31557600 + ( D + E + F ) \times 10 16 ) / P / 10^9\\&= 4.795721689 \times 0.4 \times A + ( ( B + C ) \times 31557600 + ( D + E + F ) \times 10^7 ) / P\\L &= 1 / J / 10^9 \times 3600000 \times K = 0.0036 / J \times K \end{align149.96 = 4 . 795721689 \times 0.4 \times 10 + 0 + 0 \times 31557600 + ( D + E + F ) \times 10^7 / 23000000$ so every year Taiwan needs to import $300.78 \times 10^{16}$ joules of energy.

Current Taiwan And USA

According to official data released [Https://goo.gl/Q2j3pS](http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2FQ2j3pS) , Taiwan's current situation is:

The Sun power in the distance of the Earth	w / Square meter	1370
Light scattering	The proportion	0.3
Light absorb by the atmosphere	The proportion	0.19
Theory limit of black body radiation from the sun into electrical energy efficiency	The proportion	0.87
Current photoelectric technology relative to the theory of black body radiation conversion efficiency limit	The proportion	**0.4**
Area of solar panels per person	Square meter	**0.070746865**
Population	1	**23395600**
Other sustainable energy	10^9 w	**1.08**
Non-sustainable energy	10^9 w	**2.62**
Import annual solar panels	10^16 joules	**0**
Import annual sustainable energy other than solar panels	10^16 joules	**0**
Import annual non-sustainable energy	10^16 joules	**431.05**
Number of seconds of year	1	31557600
Country area	Square kilometers	36190
Solar panels area with respect to total land area ratio	The proportion	**4.57354E-05**
Energy per capita	10^9 joules / year	**189.3705742**
Electricity fee	Fiat currency / KWh	**2.7**
Gross househode annual income	Fiat currency	**665415**
Gross household annual income	10^9 joules	**887.22**

The gap between 189.37 and 887.22 suggests that Taiwan saves a lot and hopes the world will not continue printing money to dilute these earned capability to command energy. If Taiwan does not import energy and maintain the current living standard and population, solar panel area for each person requires 96.11 square meters and the ratio of solar panel area with respect to total land will be 0.06 which is also the reduction in services provided by wild land.

According to the official figures of United States [Https://goo.gl/SFfvzC](http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2FSFfvzC) and (http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2FeuSZ9D) , United States current situation is:

The Sun power in the distance of the Earth	w / Square meter	1370
Light scattering	The proportion	0.3
Light absorb by the atmosphere	The proportion	0.19
Theory limit of black body radiation from the sun into electrical energy efficiency	The proportion	0.87
Current photoelectric technology relative to the theory of black body radiation conversion efficiency limit	The proportion	**0.4**
Area of solar panels per person	Square meter	**1.36026**
Population	1	**324118787**
Other sustainable energy	10^9 w	**284.1**
Non-sustainable energy	10^9 w	**2265.61**
Import annual solar panels	10^16 joules	**0**
Import annual sustainable energy other than solar panels	10^16 joules	**0**
Import annual non-sustainable energy	10^16 joules	**1344.07**
Number of seconds of year	1	31557600
Energy per capita	10^9 joules / year	**292.3285486**

(http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2Fn5jGXR) page 10 United States 2003 Annual roof area 5800 Square kilometers. [Https://goo.gl/U1tR4l](http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2FU1tR4l) America 2003 historical data 291005482 population. Assuming the population proportional to total housing area, solar panel area per person can be 17.89 square meters. So if United States does not use non-sustainable energy and remains the population and the roof are full of solar panels, energy per capita will be 61.98 x 10^9 joules, only Azerbaijan's living standard.

Both Taiwan and United States import energy to sustain living standard. Removing the import, United States energy per capita will be 250 x 10^9 joules, only Finland or Australia's living standard. Much worse for Taiwan, the energy per capita will be 5.12 x 10^9 joules. Therefore, an easy trick of lifting living standards can always be done through the expansion of the economy where every country can improve national income, then tax money from the people to buy more energy. Wrong, because of conservation of energy, energy cannot be created from thin air, not like fiat currency which governments can print as more as they want. If country A imports energy from country B to improve country A's energy per capita, for example, installing solar panels in the territory of country B, then country B must give up some of its own solar panel area, meaning that the goal for energy per capita of country B will be reduced.

Problem 5

Using only sustainable energy. If everyone in the world lives United States living standard, how much must be the area of solar panels per person?

Ans: Data in (http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2Fn5jGXR) Page 9. The country is the globe, and other sustainable energy including, water 230 x 10^9 w, tide 0.05 x 10^9 w, wind 5 x 10^9 w, geothermal 5 x 10^9 w, bio 190 x 10^9 w, solar water heater 0.6 x 10^9 w, total 430.65 x 10^9 w. United States living standard by (http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2FHFdhxJ) is 290.47 x 10^9 joules. Population by (http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2FU1tR4l) is 7464000000. Because "the world" has no foreign countries, D, E and F are all zero. Solving the formula, the solar panel area per person is 150 square meter; essentially everyone is living in a mansion directly or indirectly, all the solar panel area will be to 0.037 of wildland areas of the planet by (http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2FmJ83PA) , So if these new solar panels are installed in the wildland, services provided by wildland ( such as cycling in fresh oxygen ) will also reduce 0.037.

The Sun power in the distance of the Earth	w / Square meter	1370
Light scattering	The proportion	0.3
Light absorb by the atmosphere	The proportion	0.19
Theory limit of black body radiation from the sun into electrical energy efficiency	The proportion	0.87
Current photoelectric technology relative to the theory of black body radiation conversion efficiency limit	The proportion	**0.4**
Area of solar panels per person	Square meter	**150.4722551**
Population	1	**7464000000**
Other sustainable energy	10^9 w	**430.65**
Non-sustainable energy	10^9 w	**0**
Import annual solar panels	10^16 joules	**0**
Import annual sustainable energy other than solar panels	10^16 joules	**0**
Import annual non-sustainable energy	10^16 joules	**0**
Number of seconds of year	1	31557600
Energy per capita	10^9 joules / year	**290.47**

  Now the big question. If everyone in the world wants to live by sustainable energy, how much can be the overall living standard? Because the relationship between population density and the solar panel area per person, without reducing population, it is almost impossible to be as same as that of the United States. The more energy per capita, the more severe reduction of population. The lower the energy per capita, the more people feel unhappy about material life although no need to reduce population. Another factor limits solar panel area is the access of a raw material necessary to solar cells. Solar cell surface needs a layer of transparent and conductive material, indium. Current mining cost is 700 USA dollars each kg meaning 2800 x 10^9 joules each kg. With mining increasingly difficult this access energy will increasingly be higher. When the access energy is comparable to the energy generated by the solar panels, it is the end of increasing solar panel area. While the best place to install solar panels is the roof followed by desert, the solar panel area is unlikely to extend and cover the whole desert of the Earth. You are the global country's dictator to set the living standard of Earth, it is your call now.

Problem 6

If the world uses sustainable energy only and doesn't reduce population and everyone can have 20 square meters of solar panels, how much is living standard?

Ans :

The Sun power in the distance of the Earth	w / Square meter	1370
Light scattering	The proportion	0.3
Light absorb by the atmosphere	The proportion	0.19
Theory limit of black body radiation from the sun into electrical energy efficiency	The proportion	0.87
Current photoelectric technology relative to the theory of black body radiation conversion efficiency limit	The proportion	**0.4**
Area of solar panels per person	Square meter	**20**
Population	1	**7464000000**
Other sustainable energy	10^9 w	**430.65**
Non-sustainable energy	10^9 w	**0**
Import annual solar panels	10^16 joules	**0**
Import annual sustainable energy other than solar panels	10^16 joules	**0**
Import annual non-sustainable energy	10^16 joules	**0**
Number of seconds of year	1	31557600
Energy per capita	10^9 joules / year	**40.18655063**

Only Tunisia's living standard by (http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2FHFdhxJ) .

Is it too harsh? Note that this conversion efficiency loss is ignored, for example, not everyone has 20 square meters of private land, so inevitably a distant energy transport is necessary and there are actually worse because the energy conversion efficiency loss is not counted.

Problem 7

By (http://www.microsofttranslator.com/bv.aspx?from=zh-CHT&to=en&a=https%3A%2F%2Fgoo.gl%2FHFdhxJ) China and India energy per capita are 93.5 and 25.45 giga joules. Because the two major population countries vow to improve living standard and accuse the selfish United States, after some political process to resolution, the Earth may set the energy per capita X between 100 and 290 and reduce a necessary portion of population. As a madman's saying "All lives matter", then how to do to accomplish the conclusion?

Ans: If you do nothing, although there have been previously unemployed coal miners to get back to work, the greater number of climate refugees will die in the end. Comparing the two numbers, you shall first kill the madman and the globe has consistent action to avoid globe national good efforts to be offset by the madman. Now a person is dead. Countries shall examine their own energy per capita and shall be guilty if higher than X. These guilt countries shall export energy to low energy per capita countries. The higher their energy per capita, the more energy export. The export method can be the trade deficit but the way to save cost is a simple energy gift and even better with an equivalent amount of gift money, but only if all countries are not allowed to increase their fiat currency volume. These exported energy action will inevitably reduce their own energy per capita therefore a reduced living standard but no population reduction. For countries of low energy per capita and living standard, they receive these gift to increase solar panel area. If their energy per capita cannot reach X yet, they have to reduce population to improve the number; policies may include random birth control or random cancellation of elder medical care. Under this process, the prime population will be responsible for big burden. Beside themselves, they need to raise the younger population as well as more number of elder population. These prime population may have liver disease and die early due to hard working. The elder population may die due to lack of medical care. Over all, these deaths are normal and inevitable in big picture though miserable. In this way, the Earth may lose least population. This plan is not to be proud of, but it shall be better than less civilized methods such as wars or killings. Anyway, who persuade people from accepting Tunisia's living standard ?

----  Real money represents energy, the world really does not need the central banks and only need the energy bureau. Now that the conservation of energy, shall people make money ? While individuals are always encouraged to make money, but if money volume is not inflated, not everyone can make money. Governments placate people's award-winning even if the available energy does not increase. By way of the inflation of currency volume, everyone will make money, and people who don't understand the nature of money are fooled because someone must be nominal wealthier than before but real poorer than before.

With the above candy example, you should already know one fiat dollar represents how much energy, provided that the government will not inflate currency volume. It is easy to calculate the energy to produce a pricy steak. 0.0036 divided by the price of electricity fee and multiplied by the steak's price is the required energy in giga joules by the globe, assuming the power company and the steak house does not earn too much. A product's complete production process is not so clear and simple. Even the last merchant who puts the product on the shelves only knows a small piece of the whole story. Upstream manufacturers have more stories about the product and the stories are difficult to imagine. A dry food does not mean that it does not require large amounts of clean water, but lots of clean water requires a lot of energy to generate. Being affordable consumers, on one hand, they should be thankful and feel lucky they could command this energy, but they also should be guilty, knowing that with this consumption the accumulated commanded energy of this year may have been more than the average energy per capita of the globe X so there must be someone who commands less energy. That is, eating the steak, somewhere in the world there must be someone unknown whose annual energy reduces to below X the globe living standard.

Many appreciate the madman as the most patriotic, saying for poor disadvantaged people. But the problem is not that one person is not as wealthy as before. Coal industry workers was miserable, but a compassion without global view is no necessary. By the physical laws, in order to avoid huge amounts of carbon dioxide from non-sustainable energy to terminate the entire civilizations, some people are impossible to have a better living standard as before. But these people will be able to find a way not to starve to death, for example, to work in the factories that produce solar panels. But who cares a global perspective or none ? Whether being madman or not, physics and mathematics still apply. With global views people can sit down and discuss a plan. Without global views, that a madman launches trade wars or directly military wars is actually that the physics and mathematics meet for such of no-thinkers people with a hard price; maybe a trade war results in bad economy and young couple not willing to have children, or people die in military wars and population are reduced accordingly, or one country conquers another country then scratches its energy, or .... ; it looks bad in the process and it could be bloody, but after all, all parts are in line with the physics and mathematics law underneath.

Ever since, people don't understand the nature of money and view the world in fiat currency and take coherent "growth" and "sustainable life" for granted because "growth" number can always be achieved by the inflated currency volume. But through the above physical and mathematical argument, this is simply an illusion. Given the gifts of constant power by the Sun, energy per capita has an upper bound for a given population. That people can't pursue higher living standard is sad but not fatal. People cannot pursue higher living standard but can pursue higher level of lives. Higher living standard and higher level of lives are two different concepts. People who see Star Wars or Star Trek can understand the difference (the above photo about Tunisia is actually Star Wars in Tunisia to build the movie framing): one alien lives in a cave with ragged wearing and utensils, a small nuclear fusion generating some electricity in front of the wall, photography with a remote friend, discussing a difficult problem. This is an example of poor living standards but high level of lives; any time people always can pursue higher level of lives. Wise alien will avoid self-destruction ( in fact they exist only because no self-destructive and then have the opportunity to be granted wise by aliens of other planets ) and choose the living standard no more than the energy per capita of the planet but enjoy a society of high level of lives. A person can live with high living standard and finish dinner and do not clean the dish by herself and start an automatic dish-cleaning-drying machine and leisurely watch TV; without moving and sitting on sofa quietly, she may feel cold and turn on indoor heating; she may be fat with ease and comfort in sofa day by day; she may need to go to fitness center and run on treadmill; no cool wind for running in fitness center, she may turn on a cooling fan. But, a person also can live with a medium living standard and clean the dish after dinner by herself; being sort of exercise, she may not feel cold and no ease and comfort in sofa for TV; accordingly, she may not get fat and no need to go for fitness center for spending money and exercise. Unlike the centipede who needs N pairs of shoes, she can also be very sexy with only one pair of flat shoes.

What else can be done ? It would be better to get nuclear fusion generator which generates cheap and inexhaustible high quality ( low entropy ) energy. Clean water and hunger is no longer a problem because people can use the powerful energy to reverse the dirty and rancid water and discarded waste organic material into freshwater and food ( the second law of thermodynamics ). Taking Earth as an example, strong solar power recycles freshwater and food. This freshwater may be pus of animal wound 1 years ago and urine of kidney disease animal 2 years ago, disgusting. Suppose Sun is red and bigger with the same energy power. By quantum mechanics, photon energy is proportional to the frequency. Although total solar energy is still the same, the water purification process may take longer or even impossible. Nuclear fusion generator will change composition of environment materials. It will decrease water and increase oxygen and helium. Helium is very light and will float out of the atmosphere, but amount of oxygen and water will change. Who knows human will find something wrong 200 years later. Just like 200 years before, people didn't know carbon dioxide of steam engine would cause trouble 200 years later (water and carbon dioxide being greenhouse gas, too much or too little is both disaster). But if humans don't act to avoid self-destruction at any moment by the current knowledge and think that they can be very lucky to invent the technology necessary to relieve a problem in a timely manner, this civilization survival issues will still happen sooner or later. 200 years is a moment for the universe. Even if I had the knowledge of highly civilized alien fusion generator, until the people on Earth are highly civilized, I did not bother to tell people this technology. "Homosapiens, Homosapiens", Interstellar Federal Of High Civilization is calling.