The graph below shows average carbon dioxide (C02) emissions per person in the United Kingdom, Sweden, Italy and Portugal between 1967 and 2007.

The line graph illustrates how the amount of CO2 per habitant changes during 40 years in four different countries, The units are measured in metric tonnes. Overall, it can be suddenly noticed that the quantity of gas released by these nations have two opposite trend that can be grouped. The first, which describe Portugal and Italy, increased starting from 1977 to 2007. Instead, UK and Sweden cut the emission during this period so the line went down. In according with datas it’s also possible to say that Italy hit a high point in 1997 with production of about 8 units but this level stayed the same for the next decade. The Portugal follows strictly the same growth but it reachs about 2 metric tonnes less with a final total of 6. In contrast with these countries, Sweden constantly slightly decrease its pollution and UK do the same although it has an initial peak of 10 in 1977. In fact, between 1967 and 1977, it adds an average of 2 units per person.