【PEP】Junior Biology Grade 7, Volume 2: The Payload of "Spaceship Earth" — The Connection Between Humans and the Biosphere

Insights from the "Spaceship Earth" Concept

The "Spaceship Earth" theory, proposed by economist Kenneth Boulding,"Spaceship Earth"has fundamentally changed how we view nature. Earth is not an infinitely expandable "cowboy prairie," but a spaceship sailing alone through space — a closed system with finite resources. Humans are not external masters of the planet, but rather the most critical "payload" and crew aboard this ship.

Core Connection Mechanisms

System Closedness: Apart from solar energy, Earth barely exchanges matter with the outside world. Freshwater, minerals, and air must all be recycled internally, meaning every pollutant released into the environment will eventually cycle back to us.
Nature of the Payload: Human survival is highly dependent on the oxygen cycle, water purification, and food supply provided by the biosphere. The breadth (geographic distribution) and depth (industrial intervention) of human activities determine the environmental quality of the spaceship.
Systemic Risk: Due to the continuity of the biosphere, localized environmental damage (such as deforestation or pollutant emissions) can turn into a global ecological crisis through atmospheric circulation and the water cycle.

QUESTION 1

In the "Spaceship Earth" model, aside from which type of energy does the Earth system receive almost no other external supplies?

Thermal energy

Solar energy

Nuclear energy

Tidal energy

QUESTION 2

Why must human activities be limited by the carrying capacity of the biosphere?

Because resources are unlimited and there's no need for conservation

Because Earth is a closed system, and waste can only be broken down and recycled internally

Because humans can always dump waste into outer space

QUESTION 3

Acid rain can affect areas thousands of kilometers from the emission source. What characteristic of "Spaceship Earth" does this demonstrate?

System isolation

System closedness and continuity

System stability

QUESTION 4

In "Spaceship Earth," the most accurate definition of humanity's role is:

External observer

The crew and "payload" of the spaceship

The designer of the spaceship's engine

QUESTION 5

If we emit sulfur dioxide (SO₂) at one end of the spaceship, since matter cannot leave the system, these substances will eventually:

Return to our living environment through cycles such as precipitation

Be completely filtered by the atmosphere and discharged into space

Disappear on their own without any consequences