The provided line graph illustrates the mean carbon dioxide release per person in four countries from 1967 and 2007: the United Kingdom, Sweden, Italy and Portugal. The units are measured in metric tonnes.
Overall, emissions in both the United Kingdom and Sweden witnessed decrease, whereas Italy and Portugal escalated over the period. Moreover, the United Kingdom was the greatest contributor to emissions among all countries.
To commence, emissions in teh United Kingdom were dominating in 1967 at approximately 11 tonnes, while in Sweden it accounted for roughly 9 tonnes. In the next 20 years, emissions in the United Kingdom and Sweden started to diminish gradually, decreasing to approximately 10 and 7 tonnes respectively. After, it continued to dwindle, staying at around 9 and 5 respectively.
At the same time, Portugal emissions, starting at roughly 1 metric tonne, started to grow, reaching 5 tonnes in 1997. Similarly, in Italy, emissions climbed from around 4 tonnes to approximately 9 in the same year. In the next 10 years, both countries rose gradually to around 5 and 8 respectively, and Portugal almost overtaking Sweden in average tonns of carbon dioxide.