Researchers say that Finland has a far denser road network than other nations in the region, which creates barriers to the expansion of the blazes. Lakes and rivers are abundant, too. With many of the California fires happening near population centers now, a lack of roads is probably not the issue.
Perhaps the most striking difference with California is of a historical nature: Northern Europe is greener today than it was 100 years ago, whereas California has lost about half of its big trees. Europe’s medieval and industrial revolution-era need for wood turned former forest areas into grasslands, especially in southern Finland.