Physical Geography — Global Desert Coverage Tropical and temperate deserts together occupy approximately what fraction of the Earth’s land surface (rounded, school-level figure)?

Introduction / Context:
Deserts (arid and semi-arid categories are often separated, but school-level summaries typically aggregate “tropical and temperate deserts”) cover a notable share of Earth’s land. Being able to recall the approximate fraction helps in understanding climate zones, biome distribution, and human settlement patterns.

Given Data / Assumptions:

• We use a rounded, commonly cited textbook value.
• “Deserts” here refers to arid regions with very low precipitation; some sources include semi-arid margins.
• The question expects an order-of-magnitude fraction rather than an exact percentage.

Concept / Approach:
Across major continental interiors and subtropical high-pressure belts, deserts such as the Sahara, Arabian, Gobi, Kalahari, Australian, Atacama, and deserts of North America occupy a substantial fraction of land. Standard primers round this to “about one-third” of Earth’s land surface when grouping tropical and temperate deserts together.

Step-by-Step Solution:

Verification / Alternative check:
Many school atlases and geography texts cite values near 30–33% for deserts and semi-deserts combined, which corresponds to roughly one-third.

Why Other Options Are Wrong:

• (1/4): Underestimates when semi-desert margins are included.
• (1/2): Overestimates land under deserts.
• (1/7): Considerably too low.

Common Pitfalls:
Confusing “desert” strictly with sand seas; many deserts are rocky or gravelly and still count toward arid coverage.

Final Answer:
(1/3)