The line graph gives information about the amount of CO2 released per person in four countries from 1967 to 2007.
Of the four countries, Portugal and Italy experienced increases in their CO2 emissions. In 1967, the quantity for per person in Italy was 4.3 metric tonnes, while that of Portugal was only 1.3. There were similar upward trends in CO2 emissions in the two countries until 2007, when the figures for Italy and Portugal reached 7.8 and 5.4 respectively. Noticeably, the CO2 release per capita in Portugal was the lowest of all four countries throughout the period.
On the other hand, each United Kingdom and each Sweden emitted less CO2 on average at the end of the time period than at the beginning. The amount for United Kingdom had remained the highest across the the whole period. IT started at 10.9 and declined to 8.7. The figure for Swedes rose from 8.7 in 1967 to 10.3 in 1977. It declined below the figure for Italians after 1990 and reached 5.4 in 2007.
Overall, each person in Portugal and Sweden had released widely differing amounts of CO2, but the amounts converged until the equaled in 2007.