The Earth Systems and The Planetary Boundary Framework

Question 1

Define environmental science

Answer 1

It is the study of how the natural world works, the impact of the environment on us, and how we affect the environment.

Question 2

List the spheres of the Earth system and describe their components

Answer 2

Lithosphere (rock), Hydrosphere (water), Atmosphere (air), Biosphere (life), and Cryosphere (frozen forms of water).

Question 3

Explain the main characteristic of the Anthropocene

Answer 3

The current geological period that has had major environmental impact from humans.

Question 4

Define the pressures on the Earth system that make up the “Quadruple Squeeze”

Answer 4

Environmental factors, abiotic factors, land management decisions, and human development.

Question 5

Explain the concept of the planetary boundaries framework, including thresholds, resilience, and uncertainties

Answer 5

Nine processes that regulate the Earth system’s stability and resilience. It involves boundaries within which human development can thrive and identifies risks of large-scale environmental changes if these boundaries are crossed.
Resilience refers to a system’s ability to maintain key functions in the face of stresses, adapt to change, and avoid reaching thresholds beyond which recovery is impossible.

Question 6

List the nine planetary boundaries and identify the four boundaries that have been crossed, according to the 2015 update to the framework.

Answer 6

o Climate change
o Biosphere
o Ozone
o Ocean acidification
o Biogeochemical flows
o Land-system change
o Freshwater use
o Aerosol
o Novel entities