How much of the Earth's land surface have humans disturbed or degraded?

Options

A. `60-70%`
B. `5-10%`
C. `30-40%`
D. `10-20%`

Answer

To determine how much of the Earth's land surface has been disturbed or degraded by humans, we can follow these steps:

### Step 1: Understand the Earth's Surface Composition
- The Earth is made up of approximately 71% water and 29% land. This means that the land surface is the area we need to focus on when considering human disturbance.

### Step 2: Analyze Human Impact on Land
- It is stated that human activities have disturbed or degraded a significant portion of the land. The options provided include:
- A) 60-70%
- B) 5-10%
- C) 30-40%
- D) 10-20%

### Step 3: Evaluate the Options
- Given that human activities such as urbanization, agriculture, deforestation, and industrialization have a profound impact on the environment, we can reasonably deduce that the percentage of land disturbed is quite high.

### Step 4: Identify the Correct Answer
- Based on the information provided in the transcript, the correct answer is that 60-70% of the Earth's land surface has been disturbed or degraded by human activities.

### Final Answer
- **60-70% of the Earth's land surface has been disturbed or degraded by humans.**

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