By what percentage (%), the total emissions of CO2 have increased from 2005 to…

Concept

Percentage increase always compares the change with the STARTING value: percentage increase = (final − initial) ÷ initial × 100.

In a sector-wise table, the total for a year is the sum of every sector entry in that year's row, so both year totals must be formed before any comparison is made.

Application

1. Total emissions in 2005 = 500 + 200 + 150 + 80 + 100 = 1030 million metric tons.

2. Total emissions in 2009 = 800 + 450 + 320 + 200 + 180 = 1950 million metric tons.

3. Increase over the period = 1950 − 1030 = 920 million metric tons.

4. Percentage increase = (920 ÷ 1030) × 100 = 89.3204... ≈ 89.32 per cent.

Cross-check

• Multiplying back confirms the figure: 1030 × 1.8932 ≈ 1950 million metric tons.

• Dividing the rise by the 2009 total instead of the 2005 total gives 920 ÷ 1950 ≈ 47.18 per cent, which uses the wrong base.

• The ratio 1950 ÷ 1030 = 1.8932, that is 189.32 per cent, expresses the 2009 total as a percentage of the 2005 total, not the increase over it.

So the total CO2 emissions rose by approximately 89.32 per cent between 2005 and 2009.