The line graph illustrates how many tons of carbon dioxide emissions belonged to every individual in four different nations: the United Kingdom, Sweden, Italy, and Portugal, over three decades from 1967 to 2007. Overall, the general trend for Italy and Portugal rose significantly, while the reverse was the case for the UK and Sweden. It can be clearly seen that the UK was the single dominant country during the whole period, whereas the opposite was true for Portugal.
Looking at the details of the UK, it started at about 11 metric tons in 1967, which then witnessed a consistent drop over the years and finished at approximately 9 metric tons, even being the highest figure in the final year. Similarly, Sweden also dipped sharply to below 6 metric tons in 2007, with an exceptional rise to over 10 metric tons in 1977, which began at nearly 9 in 1967.
Turning to the amount of the other two countries, namely Italy and Portugal, the former was ranked the third-largest in 1967 with over 4 metric tons, followed by a considerable increase and reaching about 8 metric tons in the ending year, surpassing Sweden. In addition, the latter started from the lowest level at 1 metric tons in the initial year, and it rocketed sharply to around 5 metric tons in 2007, reaching parity with Sweden.