What would the Earth be like without people?

A Scientific American animation considers the question of what would happen if suddenly all humans disappeared from the Earth. There are many examples of the unreal (we hope) conditional.

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What would the Earth be like without people?

Imagining a situation that is not real – we hope

Several years ago, the famous magazine Scientific American considered the question of what would happen if suddenly all humans disappeared from the Earth. New York City was used as the example. The magazine considered what would happen very quickly, after 10 years, and after one hundred, one thousand and ten thousand years.

Below is a short video giving the main conclusions. In it, you will find many good examples of conditionals. Watch and listen and then read the transcript. List at least four things that would happen quite quickly.

Notice that when the video talks about specific future times, it stops using the conditional. Instead it has us imagine that we are there, seeing for ourselves what is happening.

Intro: What do you suppose that noise was?

Imagine that one morning, the day started like any other, but with one big difference. All humans had vanished. What would the Earth be like without people?

Obviously much quieter, but what would actually happen? Could nature wipe out all traces of our existence?

Some things would change very quickly. First the power utilities would start to shut down. In a city like New York, the pumps in the subways would switch off and the water would pour in. The streets above would erode quickly (and) collapse.

Within days nature would begin its reclamation. Without the constant attention of humans, the exteriors of buildings would become filthy, crack and vegetation would start to take root. Step by step a strange new urban ecosystem would begin to develop – and quickly.

Ten years along and Central Park is becoming the swampy wilderness that it was to begin with.

One hundred years pass. The steel infrastructure of many buildings is corroding. The facades are coming off and some begin to collapse. What were once bustling avenues are now river canyons.

One thousand years later and who knows? Global warming, the proliferating descendants of zoo animals and Central Park might start to look like somewhere in Africa.

Ten thousand years pass. Perhaps some trace of our civilization remains, not just the toxic waste we created to fuel our existence. An Earth without people would probably be very different, but then who would ever know?

Ending: What do you suppose that noise was?

imagine – to form a picture of something or someone in your mind นึกคิด, จินตนาการ, นึกฝัน
vanish – to disappear or stop being present or existing, especially in a sudden, surprising way  หายไป
trace – a slight sign that someone has been present or that something has happened ร่องรอย
existence – the state of being a real or living thing, or of being present in a particular place, time, or situation การดำรงอยู่,การมีอยู่,การมีชีวิตอยู่,ความเป็นอยู่
power utility – a company that provides electricity   for people to use
erode – to rub or be rubbed away gradually กร่อน, กัดกร่อน
collapse – to fall down suddenly พังลงมา  ล้ม, พังครืน
reclamation – the process of taking something back; in this case, the environment returning to its natural condition, i.e, the process of reclaiming  การฟื้นสภาพที่ดิน, การแปรสภาพที่ดิน
exterior – the outside part of something, especially a building ภายนอก
filthy – very dirty สกปรกที่สุด
crack – to break in a way that a long thin line appears on the surface of something, but does not cause it to break into pieces แตกร้าว
take root – to begin to grow เริ่มเติบโต
urban – connected with towns and cities เขตเมือง
ecosystem – all the plants and animals in a particular area, considered as a system with parts that depend on one another ระบบที่เกิดจากความสัมพันธ์ระหว่างสิ่งมีชีวิตและสิ่งแวดล้อม
swampy – covered with water, trees and plants ซึ่งเป็นหนองน้ำ, ฉอะแฉะ
wilderness – a large area of land that has never been developed or used for growing crops because it is difficult to live there; บริเวณรกร้างว่างเปล่า
infrastructure – the structure inside a building that holds it together โครงสร้างพื้นฐาน
corrode – (of a metal or other substance) to destroy/to be gradually destroyed by a chemical process กัดกร่อน
façade – the front of a building, especially one that is large or impressive ด้านหน้าของตึกที่แสดงรายละเอียดของสถาปัตยกรรม, ส่วนหน้าของอาคาร
bustling – full of busy activity อึกทึกครึกโครม
canyon – a long deep valley with very steep sides หุบเขาลึก
proliferating – quickly increasing in number or amount  เพิ่มจำนวนอย่างรวดเร็ว
descendant – a relative of a person, or in this case, an animal, that lived in the past ทายาท, ผู้สืบสายเลือด
civilization – a society, its culture and its way of life during a particular period of time or in a particular part of the world อารยธรรม,การมีวัฒนธรรมประเพณี
toxic waste – poisonous and harmful waste products, like nuclear waste

To further understand conditionals, read the chapter in Understanding English verb forms: Understanding conditionals

You can find a full description of Understanding English verb forms here:


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About the author

Writer: Terry Fredrickson
Position: Education Marketing and Support Manager