Type I Civilization (Planetary Civilization): Capable of harnessing all the energy available on its home planet (e.g. Earth). Carl Sagan estimated this total power output to be 1e+16 watts.
Type II Civilization (Stellar Civilization): Capable of harnessing the total energy output of its parent star, potentially through the construction of a Dyson Sphere. Carl Sagan estimated this total power at 1e+26 watts.
Type III Civilization (Galactic Civilization): Capable of harnessing all the energy of its host galaxy. Carl Sagan estimated this total power at 1e+36 watts.
Carl Sagan used the values for Type I, Type II, and Type III to interpolate and extrapolate the following formula:
Where is the Kardashev rating and is the power in watts.
In 2024, the total power consumption of human society was approximately 2e+13 watts, with a population of about 8e+9. To maintain the current global average standard of living, the per capita power consumption is approximately 2,500 watts.
The per capita energy consumption in the United States is roughly 4.8 times the world average. To provide every person on Earth with the current American standard of living, the total global power output would need to increase significantly; the current total power is clearly insufficient.
According to the Global Wealth Report 2025 published by UBS, by the end of 2024, the Total Global Wealth was approximately $471 trillion.
The average wealth per adult globally is approximately 8,654.
In terms of per capita wealth, the average in the United States is approximately 76,000.
| Rank | Country/Region | Wealth per Adult (USD) | Median Wealth (USD) |
|---|---|---|---|
| 1 | Switzerland | $687,166 | $171,035 |
| 2 | United States | $620,654 | $112,157 |
| 3 | Hong Kong SAR | $601,195 | $206,859 |
| 4 | Luxembourg | $566,735 | $311,194 |
| 5 | Australia | $516,640 | $261,819 |
| 6 | Denmark | $481,558 | $186,303 |
| 7 | Singapore | $441,596 | $104,959 |
| 8 | New Zealand | $393,773 | $201,311 |
| 9 | Netherlands | $370,697 | $118,521 |
| 10 | Norway | $368,410 | $143,887 |
| 11 | Canada | $365,953 | $142,587 |
| 12 | Belgium | $349,404 | $241,841 |
| 13 | United Kingdom | $339,700 | $153,592 |
| 14 | Sweden | $334,391 | $84,982 |
| 15 | Taiwan | $312,075 | $110,500 |
| 16 | France | $301,503 | $130,689 |
| 17 | Israel | $284,224 | $101,650 |
| 18 | Ireland | $258,357 | $97,801 |
| 19 | Germany | $256,715 | $62,911 |
| 20 | South Korea | $251,223 | $91,950 |
| — | Global Average | $84,718 | $8,654 |
| — | Mainland China | $75,731 | $27,273 |
Directly selecting $85,000 as a personal standard, assume this person lives in China and spends 2,500 RMB per month (for reference, the minimum wage standard in Beijing is 2,540 RMB), with an exchange rate of 7.
85,000 × 7 = 595,000 CNY
595,000 ÷ 2,500 = 238 months
238 ÷ 12 ≈ 19.8 years
Keep in mind that this is based on $85,000, which includes real estate and fixed assets—items that are subject to depreciation.
Rounding this to 20 years, it demonstrates that the total global wealth is far from sufficient to support the world’s population in a long-term life without work, nor can it provide a wealthy lifestyle for everyone on Earth.
In summary, the current total power output of humanity is struggling to support a wealthy standard of living (the average American standard of living), and the total global wealth is also insufficient to allow everyone to lead a wealthy life.
References: