HSC Geography · Human–Environment Interactions

# 12.2 Land Cover Change at a Global Scale

Deforestation · desertification · retreating ice · NESA Stage 6 (2022) · Revision deck
By the end you can…

## Learning goals

- Define land cover change and its three global forms.
- Explain deforestation's double blow (biodiversity + carbon).
- Describe the desertification cycle (the Sahel).
- Account for retreating ice and why it matters.
- Evaluate the 2022 “30×30” agreement.

Section 1

# What is land cover change?

## Three global changes

Deforestation

Clearing tropical forest for farming, logging, roads.

Desertification

Dryland degrading to desert-like conditions.

Retreating ice

Glaciers & ice sheets melting at poles & peaks.

Each clusters by climate zone — and each is human–environment interaction at a global scale.

Section 2

# Deforestation

## Deforestation: a double blow

Biodiversity loss

Habitats destroyed; species to extinction; ecosystems destabilised.

Carbon released

Stored carbon to the air and a carbon sink destroyed.

Cleared for cattle, soy, palm oil, logging, mining, roads — fastest in the tropics.

## Case study: the Amazon

More than half the world's tropical rainforest

~17–20% cleared (mainly cattle & soy); a vast carbon store at risk of a dieback tipping point.

Environment Interconnection Sustainability
The response

# “30×30” — 2022

## Kunming–Montreal Framework (COP15)

- ~196 governments; 23 targets.
- Flagship: protect 30% of land & oceans by 2030.
- Plus: restore ecosystems, cut harmful subsidies.

Evaluate it: near-universal & measurable, but voluntary — funding & enforcement are the test.

Section 3

# Desertification

## The desertification cycle

Affects over 100 countries; the Sahel is the classic case.

## Case study: the Sahel

The semi-arid belt south of the Sahara

Drought + overgrazing + fuel-wood + population growth. Response: the Great Green Wall.

Environment Change Sustainability
Section 4

# Retreating glaciers & ice

## Ice in retreat

Kilimanjaro

>80% of ice lost since 1912.

Himalayas

“Third Pole” — rivers for ~2 billion people.

Greenland

Losing mass; raising sea levels.

Ice = freshwater store and sea-level driver — monitored from space (satellite imagery).

Big picture

# The Anthropocene

## A human-shaped planet

Land cover change is so widespread that human activity is now a planetary geological force — the case for a new epoch, the Anthropocene.

Debate: “There is no longer such a thing as a purely natural system.”

Recap

# 12.2 in one screen

## Pull it together

- Land cover change = deforestation, desertification, retreating ice.
- Deforestation = biodiversity loss + carbon double hit (Amazon).
- Desertification = a feedback cycle (the Sahel; Great Green Wall).
- Ice loss threatens freshwater & raises seas (Kilimanjaro, Greenland).
- Global response: 30×30 (2022) — evaluate its effectiveness.

Next: Chapter 13 — Climate Change.

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