The line graph delineates the per capita carbon dioxide emissions in the United Kingdom, Sweden, Italy, and Portugal across a forty-year period, from 1967 to 2007. Overall, the UK and Sweden exhibited a downward trajectory in emissions, contrasting with the upward trends observed in Italy and Portugal.
In 1967, the United Kingdom recorded the highest emission levels, commencing at approximately 10 metric tonnes per person, before experiencing a gradual decline to just under 9 metric tonnes by 2007. Sweden’s emission curve peaked around 1977, exceeding 10 metric tonnes, followed by a pronounced decrease over the subsequent decade and a continued, albeit gentler, descent to roughly 6 metric tonnes by the end of the period. Notably, around 1987, Italy and Sweden converged at similar emission levels, despite their divergent trajectories.
Conversely, Italy demonstrated a consistent increase in per capita CO₂ emissions, plateauing at approximately 7 metric tonnes towards 1997 and remaining relatively stable thereafter. Portugal, starting from a significantly lower base of around 1 metric tonne in 1967, witnessed a steady escalation in its emission levels, ultimately converging with Sweden at approximately 6 metric tonnes per person by 2007.