Carbon dioxide and global warming: the greenhouse effect

3 marks · Normal

In the year 1800, the concentration of carbon dioxide (CO₂) in the atmosphere was about 280 parts per million (ppm). In 2020, it was measured at approximately 410 ppm.

Calculate the percentage increase in carbon dioxide concentration in the atmosphere between 1800 and 2020. Show your working and give your answer to 1 decimal place.

Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.

Show answer

46.4% (±0.1)

Also accept: 46% (accept if rounded appropriately)

Common mistakes: Calculating percentage of 410 instead of % increase; Incorrectly subtracting then failing to divide by original

Show mark scheme and worked solution

Marking points

M1 · 1 mark · Subtracts the initial value from the final value (410 - 280 = 130)

M2 · 1 mark · Divides the change by the original value and multiplies by 100 to find percentage increase (follow-through)

A1 · 1 mark · Correct final answer: 46.4% (accept 46%) to 1 decimal place (follow-through)

Worked solution

Percentage increase = (change/original) × 100