The graph illustrates the average carbon dioxide emissions per person in four European countries from 1967 to 2007.
Overall, the figures for Italy and Portugal increased, while those for the United Kingdom and Sweden decreased. The United Kingdom had the highest CO₂ emissions throughout the entire period.
In 1967, Italy produced around 4 metric tonnes per person. This number increased significantly to 6 tonnes in 1977 and then increased slightly to nearly 8 tonnes by 2007. Portugal, meanwhile, began with about 1.5 tonnes in 1967. It increased slightly to 3 tonnes by 1977 and rose significantly to just over 5 tonnes in 2007.
The United Kingdom started at around 11 tonnes in 1967. It decreased slightly to 10 tonnes in 1987 and then dropped to about 9 tonnes in 2007. Similarly, Sweden began at 9 tonnes, increased slightly to 10 in 1977, but later decreased significantly to roughly 5.5 tonnes by 2007.