A study conducted at Yale University and published in Nature magazine estimates that planet Earth is home to some 3,040,000,000,000 trees – that's just over 3 trillion. The same number of trees, incidentally, has been felled since the beginning of human civilisation.The study indicates that Finnish forests are the densest to be found in comparison to the rest of the world's countries, with some 72,000 trees covering the average Finnish square kilometre. The top 5 list also includes Slovenia, Sweden and Taiwan.
Globally speaking there are 420 trees towards each person on the planet, while there are nearly 4,500 trees for each Finn – putting the number of trees in Finland at around 22 billion. Approximately 1.39 trillion trees exist in tropical and subtropical forests, with 0.74 trillion in boreal regions and 0.61 trillion in temperate regions.