5千年之後地球會是怎樣子?

5千年之後地球會是怎樣子?
What will Earth look like in 5,000 years?

Human technology has advanced significantly over the past 5,000 years, and the Earth bears the scars to prove it. We've altered the landscape, the climate and the biological diversity. We've erected skyscrapers for the living and colossal tombs for the dead. Perhaps most important, we've learned to harness a portion of the planet's energy, but we still thirst for so much more power.

This insatiable appetite for energy will continue to chart the course of human civilization in the 5,000 years to come. As a result, it will also dictate what Earth will look like in A.D. 7010.

In 1964, Russian astrophysicist Nicolai Kardashev theorized that a civilization's technical advancement directly correlates to the amount of energy its citizens can manipulate. Along these lines, he defined three classifications for advanced civilizations in the galaxy:

1. Type I civilizations are masters of planetary energy, meaning that they can harness the sum energy of an entire world.
2. Type II civilizations can summon the power of an entire star system.
3. Type III civilizations command energy on a galactic scale.

Cosmologists use this Kardashev Scale to predict the technical advancement of future and alien civilizations. Currently, modern humans don't even rank on the scale. We're essentially a type 0 civilization, but we'll eventually become a type I. Kardashev himself predicted that this transition would occur. But when?

Theoretical physicist and futurist Michio Kaku forecasts this transcendence occurring within a mere century. Physicist Freeman Dyson raises that estimate to less than 200 years. Back in the day, Kardashev envisaged that it would take only 3,200 years to reach type II status.

If humanity only reaches type I status by A.D. 7010, then it will still have the ability to manipulate and control atmospheric and geothermal forces. Warfare and self-destruction might still pose a threat to humanity's survival, but ecological concerns will be a thing of the past.

If we achieve type II status by that point, then 71st century humans will wield even greater technological power. Dyson proposed that such a civilization would be capable of encapsulating a star with a swarm of satellites to harvest its energy. Other theorized type II feats include interstellar travel and the ability to move entire planets -- and all this on top of whatever breakthroughs have occurred in genetics and computing.

Such future humans will likely differ greatly from us culturally or even neurologically. They may well be what futurists and philsophers refer to as posthumans or transhumans.

Regardless, a lot can happen in 5,000 years. We might destroy ourselves with warfare or unwittingly ravage the planet with nanotechnology. Perhaps we'll fail to mitigate the threat posed by asteroid and comet collisions. We might even encounter an alien type II civilization long before we achieve that level ourselves.

Explore the links below to learn even more about humanity's future.

Related HowStuffWorks Articles

• How Global Warming Works
• How Moore's Law Works
• How Terraforming Mars Will Work
• 5 Future Technology Myths
• How will we have children in the future?
• What will the Earth look like in 500 years? 

https://science.howstuffworks.com/environmental/earth/geology/earth-5000-years.htm