Free Printable Human Population Growth Worksheet - Free Printable

Let’s solve this step by step using the data provided.

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## 📊 Step 1: Understand the Data

We are given population data from 1650 to 2011:

| Year A.D. | Population (billions) |
|-----------|------------------------|
| 1650 | 0.50 |
| 1750 | 0.70 |
| 1850 | 1.0 |
| 1925 | 2.0 |
| 1956 | 2.5 |
| 1970 | 3.6 |
| 1980 | 4.4 |
| 1991 | 5.5 |
| 2000 | 6.0 |
| 2004 | 6.4 |
| 2008 | 6.7 |
| 2011 | 6.9 |

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## 🔍 Analysis Question 1: Doubling Time

> “It took 1,649 years for the world population to double from .25 billion people to .50 billion people.”

This is historical context — we start our doubling calculations from 0.5 billion in 1650.

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a. Second Doubling: From 0.5B → 1.0B

- Start: 0.5B in 1650
- End: 1.0B in 1850
- Time taken = 1850 – 1650 = 200 years

✔ Answer a: 200 years

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b. Third Doubling: From 1.0B → 2.0B

- Start: 1.0B in 1850
- End: 2.0B in 1925
- Time taken = 1925 – 1850 = 75 years

✔ Answer b: 75 years

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c. Fourth Doubling: From 2.0B → 4.0B

Wait — we don’t have exactly 4.0B, but we have:

- 2.0B in 1925
- 4.4B in 1980 → that’s *more than* 4.0B

So let’s find when it reached ~4.0B.

Looking at the data:

- 1970: 3.6B
- 1980: 4.4B

We can interpolate or estimate.

Assume linear growth between 1970 and 1980:

From 3.6B → 4.4B in 10 years → increase of 0.8B per decade.

To reach 4.0B from 3.6B: need 0.4B increase.

Time needed = (0.4 / 0.8) × 10 = 5 years

So approx. year = 1970 + 5 = 1975

Thus, time from 1925 to 1975 = 50 years

✔ Answer c: ~50 years

*(Note: Some sources may say 4B was reached in 1974 — close enough.)*

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## 📈 Analysis Question 2: Rate of Growth

We see the doubling times:

- 1st doubling (0.25→0.5): 1649 years
- 2nd (0.5→1.0): 200 years
- 3rd (1.0→2.0): 75 years
- 4th (2.0→4.0): ~50 years

The time to double is decreasing → meaning population is growing faster over time.

✔ Answer 2: The human population has INCREASED at an ACCELERATED rate.

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## 📅 Analysis Question 3: When will population reach 8 billion?

We need to graph the data first (as per directions), then extend the trend.

But since we can’t draw here, we’ll analyze the recent growth rate to project forward.

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Recent Data (2000–2011):

- 2000: 6.0B
- 2004: 6.4B → +0.4B in 4 years → 0.1B/year
- 2008: 6.7B → +0.3B in 4 years → 0.075B/year
- 2011: 6.9B → +0.2B in 3 years → ~0.067B/year

Growth is slowing slightly, but still significant.

Let’s use average growth rate from 2000 to 2011:

- 2000: 6.0B
- 2011: 6.9B → +0.9B in 11 years → ~0.0818 billion per year

To go from 6.9B to 8.0B → need 1.1 billion more

Time needed = 1.1 / 0.0818 ≈ 13.45 years

So, 2011 + 13.45 ≈ 2024.5 → mid-2024

✔ Answer 3: Around 2024

*(Note: In reality, world population reached 8 billion in November 2022 — so our projection is close!)*

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## ✔ Final Answers:

1. a. 200 years
b. 75 years
c. ~50 years

2. increased / accelerated

3. ~2024

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## 📌 Extra Tip for Graphing (if you’re doing this on paper):

- X-axis: Years 1650 to 2050 (scale: maybe 1 cm = 50 years)
- Y-axis: Population 0 to 8 billion (scale: 1 cm = 1 billion)
- Plot points from table
- Draw a smooth curve (best-fit line) — it should be exponential, curving upward steeply after 1900
- Title: “Human Population Growth from 1650 to 2011”

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Let me know if you’d like help drawing the graph digitally or interpreting trends further!