The Composition of Earth’s Atmosphere

Summary

This script explores Earth's atmosphere, highlighting its thin layer that shields us from the vacuum of space. It covers the atmosphere's structure, with most human activity confined to the first 40 kilometers. The composition is detailed, with nitrogen at 78%, oxygen at 21%, and trace gases like argon and carbon dioxide at 0.04%. The importance of understanding atmospheric composition and the stable percentages of gases over 200 million years are emphasized, setting the stage for lessons on the atmosphere's origins.

Takeaways

• 🌎 The Earth's atmosphere is a thin layer that protects us from the vacuum of space, with an approximate thickness of 100 kilometers.
• 🌐 Earth is a nearly spherical ball of rock, about 12,750 kilometers in diameter.
• ✈️ Commercial airlines typically fly between 10 and 15 kilometers, while military aircraft can reach up to 30 kilometers.
• 🏔 The highest permanent human settlement, La Rinconada in Peru, is at 5,100 meters above sea level.
• 🧗‍♂️ Humans have reached the top of Mount Everest (8,848 meters) without oxygen, but cannot stay for long due to the thin air.
• 🌀 The atmosphere's composition is primarily nitrogen (78%), oxygen (21%), and trace amounts of other gases like argon and carbon dioxide (0.04%).
• 🌿 Carbon dioxide, despite its significant role in climate change, makes up a very small fraction of the atmosphere.
• 🔢 Scientists use various units to express trace gas concentrations, including percentages, parts per million (ppm), and parts per billion (ppb).
• 🌬️ The composition of the atmosphere has remained relatively stable for the last 200 million years, with nitrogen and oxygen being the dominant gases.
• 🌟 Other trace gases in the atmosphere include noble gases like neon, helium, and krypton, as well as methane and various pollutants.

Q & A

What is the Earth's atmosphere when viewed from space?

The Earth's atmosphere, when viewed from space, appears as a thin blue line at the edge of the planet.

How thick is the Earth's atmosphere?

The Earth's atmosphere is approximately 100 kilometers across, although its outer edge gradually fades into the vacuum of space, making it difficult to determine an exact thickness.

What is the approximate diameter of the Earth?

The Earth is an approximately spherical ball of rock about 12,750 kilometers across.

Up to what altitude do commercial airlines typically fly?

Commercial airlines fly between 10 and 15 kilometers up.

What is the highest altitude at which humans can struggle to breathe without the aid of an aircraft?

Without the safety of an aircraft, humans struggle to breathe above a few kilometers into the air.

What is the highest permanent human settlement in terms of altitude?

The highest permanent human settlement is La Rinconada in Peru, which sits about 5,100 meters above sea level.

What is the composition of Earth's atmosphere in terms of the most common gases?

The composition of Earth's atmosphere is approximately 78% nitrogen, 21% oxygen, and trace amounts of other gases like argon.

What is the percentage of carbon dioxide in the Earth's atmosphere?

Carbon dioxide makes up only 0.04 percent of the Earth's atmosphere.

How is 0.04 percent expressed in parts per million (ppm)?

0.04 percent is the same as 400 parts per million (ppm).

What other gases are present in the Earth's atmosphere besides nitrogen, oxygen, and argon?

Other gases in the Earth's atmosphere include trace amounts of inert gases like neon, helium, and krypton, as well as about one to two parts per million of naturally occurring methane.

How have the percentages of common gases in the Earth's atmosphere changed over the last 200 million years?

The percentages of common gases in the Earth's atmosphere have hardly changed at all for the last 200 million years, remaining approximately four-fifths nitrogen and one-fifth oxygen.

Outlines

00:00

🌍 Earth's Atmosphere and Its Composition

This paragraph introduces the Earth's atmosphere as viewed from space, highlighting the thin blue line that signifies the boundary between Earth and the vacuum of space. It emphasizes the spherical shape of Earth and the relative thinness of its atmosphere, which is approximately 100 kilometers thick. The atmosphere's structure is explored, noting that most human activity and weather occur within the first 40 kilometers. Commercial and military aircraft fly within specific altitudes, and humans struggle to breathe without assistance above a few kilometers. The highest permanent human settlement, La Rinconada in Peru, is mentioned as an example of human habitation at high altitudes. The paragraph also discusses the composition of the atmosphere, with nitrogen being the most abundant gas at approximately 78%, followed by oxygen at 21%, and trace amounts of argon and carbon dioxide at 0.04%. The significance of understanding these proportions and the potential for encountering these figures in various units, such as parts per million (ppm), is also highlighted.

05:00

🌬️ Stability of Earth's Atmosphere Over Time

The second paragraph discusses the stability of the Earth's atmosphere over a vast timescale, noting that despite human activities and pollution, the composition of the main gases has remained largely unchanged for the last 200 million years. It provides historical context by comparing the current composition to that of the time of early dinosaurs. The paragraph outlines the basic figures for the composition of the atmosphere, with nitrogen constituting about four-fifths (80%) and oxygen one-fifth (20%). It also mentions the presence of carbon dioxide, water vapor, and noble gases in smaller proportions. The importance of understanding these percentages and being able to recall them in various forms, such as fractions, ratios, and parts per million, is emphasized for exam preparation. The paragraph concludes by预告ing the next lesson, which will delve into the origins of the Earth's atmosphere.

Keywords

💡Atmosphere

The atmosphere is the layer of gases surrounding the Earth. It plays a crucial role in protecting life by absorbing solar radiation, warming the planet, and creating the conditions necessary for life as we know it. In the video, the atmosphere is described as a 'thin blue line' when viewed from space, emphasizing its relative thinness compared to the Earth's size and its vital role in sustaining life.

💡Vacuum of Space

The vacuum of space refers to the near absence of matter, including air, in the space outside of Earth's atmosphere. It is a hostile environment for humans and life as we know it. The video uses the concept to highlight the importance of Earth's atmosphere, which acts as a protective barrier against the vacuum.

💡Nitrogen

Nitrogen is the most abundant gas in Earth's atmosphere, making up about 78% of the air we breathe. It is essential for life as it is a component of amino acids, which are the building blocks of proteins. In the script, nitrogen is mentioned as the most common gas, highlighting its dominance in the composition of the atmosphere.

💡Oxygen

Oxygen is the second most abundant gas in the atmosphere, constituting about 21% of the air. It is vital for most life forms as it is necessary for cellular respiration. The video mentions oxygen as the next most common gas after nitrogen, emphasizing its importance for human survival.

💡Argon

Argon is an inert gas that makes up a small fraction of Earth's atmosphere, approximately 0.93%. It is used in various industrial applications, such as in light bulbs and welding. The script includes argon as part of the last 1% of the atmosphere's composition, illustrating the variety of gases present.

💡Carbon Dioxide

Carbon dioxide is a trace gas in the atmosphere, making up only about 0.04%. Despite its low concentration, it is significant for photosynthesis in plants and as a greenhouse gas contributing to global warming. The video discusses carbon dioxide in the context of human activities and their impact on the atmosphere.

💡Parts Per Million (ppm)

Parts per million is a unit of measurement used to describe the concentration of a substance in a mixture. In the context of the video, ppm is used to express the small concentration of carbon dioxide in the atmosphere, with 0.04% being equivalent to 400 ppm.

💡La Rinconada

La Rinconada is the highest permanent human settlement, located in Peru at an altitude of about 5,100 meters. The video mentions it to illustrate the extreme conditions humans can endure, albeit with difficulty, highlighting the limits of human habitation in relation to atmospheric conditions.

💡Everest

Mount Everest is the highest peak on Earth, standing at nearly 9 kilometers above sea level. The video refers to the fact that humans have climbed Everest without oxygen, showcasing human achievement and the limits of human endurance in high-altitude environments.

💡Inert Gases

Inert gases, such as neon, helium, and krypton, are chemically unreactive and make up a tiny fraction of the Earth's atmosphere. They are mentioned in the script to complete the list of gases present, emphasizing the diverse composition of the atmosphere.

💡Methane

Methane is a potent greenhouse gas that occurs naturally in small amounts, about one to two parts per million in the atmosphere. It is also a byproduct of human activities, such as agriculture and fossil fuel extraction. The video includes methane as an example of naturally occurring gases that are part of the atmosphere's composition.

Highlights

The Earth's atmosphere appears as a thin blue line when viewed from space, protecting us from the vacuum of space.

Earth is a roughly spherical rock about 12,750 kilometers in diameter.

The atmosphere is difficult to measure precisely due to its gradual fade into space, but is generally accepted to be about 100 kilometers thick.

Most weather and human experience occur within the first 40 kilometers of the atmosphere.

Commercial airlines fly between 10 and 15 kilometers, while military aircraft can reach twice that altitude.

Above 30 kilometers, only a few weather balloons are found, and humans struggle to breathe without supplemental oxygen.

The highest permanent human settlement, La Rinconada in Peru, is at 5,100 meters above sea level.

Humans have walked on Everest without oxygen, nearly 9 kilometers above sea level, but cannot stay for long.

The first few kilometers of air are crucial for human survival.

The composition of the atmosphere is a mixture of three main gases: nitrogen, oxygen, and argon.

Nitrogen is the most common gas, making up approximately 78% of the atmosphere.

Oxygen is the second most common, at 21%.

Argon, an inert gas, makes up the remaining 1% of the atmosphere's composition.

Carbon dioxide, despite its significance in news and environmental discussions, constitutes only 0.04% of the atmosphere.

Understanding units like percentages, parts per million (ppm), and ratios is important for scientific and exam contexts.

Other gases in the atmosphere include trace amounts of neon, helium, krypton, and naturally occurring methane.

Pollutants are also present in the atmosphere, though their impact is minimal compared to the main gases.

The percentages of common gases in the atmosphere have remained stable for the last 200 million years.

The ratio of nitrogen to oxygen is approximately four to one.

Memorizing the percentages and units of atmospheric gases is beneficial for exams and understanding the planet's atmosphere.

The next lesson will explore the origins of the atmosphere, dating back to the early days of the planet.

Transcripts

this

is the earth's atmosphere when viewed

from space

that thin blue line at the edge of the

planet

is all that stands between you and the

vacuum of space

the earth is an approximately spherical

ball of rock

about twelve thousand seven hundred and

fifty kilometers across

and our atmosphere is really a thin

skin across the surface of the planet

it's a bit hard to get an exact

thickness of our atmosphere

because the outer edge gradually fades

into the vacuum of space

but most people accept that it is about

a hundred kilometers across

almost all of our weather and our

experience in the atmosphere

is limited to the first 40 kilometers

we can look at the structure of our

atmosphere a little more closely in this

diagram

commercial airlines fly between 10

and 15 kilometers up military aircraft

can fly up to twice that and above 30

kilometers

all you'll encounter will be a couple of

weather balloons

without the safety of an aircraft humans

struggle to breathe

above a few kilometers into the air

the highest permanent human settlement

is la riconada

in peru and that sits about 5

100 meters above sea level

and although humans have walked on the

top of everest without

oxygen which is nearly nine kilometers

above sea level

they have not been able to stay there

for very long

and so it is just these few kilometers

of air

that keep us alive

now i should point out that the examiner

will not ask you to recall the

dimensions

of the earth's atmosphere however it is

important for you to have a sense of

scale for the planet you live on

and the vital nature of those first few

kilometers of air

the examiner will ask you about the

composition of today's atmosphere

which is a mixture of three main gases

you need to know their names

and the percentages of each one the

composition may surprise you

first of all the most common gas by far

is nitrogen

and not oxygen discounting any water

vapor that we might find

our air is approximately 78 nitrogen

the next most common is oxygen at 21

and the last 1 is mainly the inert gas

argon now you hear quite a bit about

carbon dioxide in the news

and of course it's carbon dioxide that

we breathe out that plants require for

photosynthesis

and that we release when we burn fossil

fuels but in actual fact

carbon dioxide makes up only 0.04

percent

of our atmosphere thinking about

that 0.04 percent we should talk briefly

about units scientists

and examiners may use another unit

one percent is the same as saying

one part out of a hundred and so

naught point one percent would be the

same as one part out of a thousand

and naught point not one percent would

be the same

as one power in ten thousand the

examiner

will talk about parts per million

and so naught point naught four percent

is the same as 400 parts

per million or 400

ppm as it gets written down

now you won't be asked to convert

between percentages

and parts per million certainly not

without the examiner giving you a

formula

but you do need to be aware of this unit

as it might turn up in tables

graphs charts or in the text of an exam

question

there are also other gases in our

atmosphere

principally the remaining inert gases

neon

helium and krypton all make up tiny

amounts of it

along with about one to two parts per

million

of naturally occurring methane other

gases

are generally referred to as pollutants

and we'll talk about them

in later lessons

so this is the air we breathe and

despite the fact that human activity and

atmospheric pollution

has made some changes to the atmosphere

over the last few hundred years

the actual size of those changes

relative to the main

gases in the atmosphere are tiny

in fact the percentages of the common

gases in our atmosphere

have hardly changed at all for the last

200 million years

and that's all the way back to the time

of the early dinosaurs

the examiner quotes the following basic

figures

that for the last 200 million years

our atmosphere has been approximately

four-fifths nitrogen

that's around 80 percent and

one-fifth oxygen that's 20 percent

and small proportions of other gases

notably carbon dioxide water vapor

and the noble gases

the examiner could choose to use

fractions

percentages or even ratios in their

questions

so it's also worth noting that the ratio

of nitrogen to oxygen

is pretty much four to one

you should make sure now that you can

recall the percentages

of the gases in the atmosphere and be

familiar with those numbers

as percentages ratios fractions

and also parts per million for the rarer

gases

take some time now and learn those off

by heart

so it will be easy marks to get in the

exam

in the next lesson we'll be looking at

where our atmosphere has come from

and we'll be taking you right the way

back to the early days of our planet

to explain its origins