Based on the provided information about the graph, the accurate statement is:
Sweden reduced carbon emissions the most.
Here's why:
- Sweden's emissions decreased from just over 4 in 2009 to almost 6 in 2010, indicating an increase, while the other countries had varying degrees of increases or smaller decreases.
- The statement about Norway producing twice as much as Finland is not supported by the figures, as it suggests Norway's emissions were significantly higher than Finland's.
- The statement about all countries but Iceland having an increase in emissions is inaccurate; Iceland's emissions were stable (6 in both years).
- Iceland producing more total carbon emissions than Denmark is incorrect since Denmark's emissions were higher in both years.
Thus, the only accurate option, assuming that reducing emissions means comparing 2009 to 2010, is that Sweden reduced its emissions the most relative to others.