The line graph below shows average carbon dioxide (co²) emissions per person in the United Kingdom, Sweden, Italy and Portugal between 1967 and 2007.

The graph illustrates the amount of CO2 emissions used by one person in four countries from 1967 to 2007, with an interval of 10 years and measured in tonnes.

Overall

Linking Words

, the United Kingdom and Sweden had a downward trend,

while

Linking Words

Italy and Portugal experienced a significant increase in pollution by CO2 over the examined period. At the beginning, in 1967, emissions in Sweden moderately rose over a decade, with 10.5 tons per person.

However

Linking Words

, between 1977 and 2007, its trend decreased considerably from 10.5 to 6.5 tonnes.

In contrast

Linking Words

, the UK over the period remained the most polluted country,

whereas

Linking Words

it had miserably declined from 10.5 to 9.5 tonnes. Italy and Portugal in 1967 were the least polluted countries. Over four decades, its trends noticeably went up and gained their highest points in 1997 and 2007.

Moreover

Linking Words

, Italy converged with Sweden in 1987 and had overtaken the second place

as

Change preposition

in

show examples

carbon dioxide pollution.