Nature .com posted a study titled “Mapping tree density at a global scale”. This study dramatically changes our understanding of the number of trees on the globe. The study’s count is 3.04 trillion trees (3.04X10^12), which replaces the previous estimate of global trees of 400billion (400X10^9). As a point of reference, the study also expresses the change as trees per humans. Considering the currently estimated total global population of 7.2 billion (7.2X10^9), the study now shows the old count of 61 trees per person has grown to 422 trees per person.
|New Count||Old Count|
|TREES PER (WORLD) CAPITA,||422||61|
TABLE 1—NATURE .COM STUDY
The study says that 15 billion trees are cut down each year. They also say that reforestation, and natural forest regeneration are less than 1% of the global forest each year. Thus if the less than 1% is said to be 1/2% it would appear that new tree growth matches the logging loss.
|TREES||PER CENT OF GLOBAL FORREST|
|RENEWAL BILLIONS||15||LESS THAN 1% (Used 0.5% as a trial)|
TABLE 2 —–NATURE.COM STUDY
In Table 2 I arbitrarily used renewal percentage of 0.5, as the authors were no more specific than “less than 1%” which 0.5% obviously is.
The authors do demonstrate that they used methods to count the number of global trees that were stronger than previous measurements.
The authors also state that the global number of trees has fallen by approximately 46% since the start of human civilization.
The authors make a point that the trees most likely logged are the big ones and they are not necessarily offset by new, smaller trees with regard to CO2 capture—- perhaps as a token offering to church of global warming.
Some thoughts. It seems the threat of logging is exaggerated. This threat could be further reduced if poor nations were able to make electricity available to their people. Fossil fuel used to provide electricity would bring about a significant reduction in the logging of trees. My use of 0.5% renewal is, of course, arbitrary but probably within the accuracy of most of the numbers provided by the authors.
The actual number for human civilization’s caused reduction of trees is 45.8%. Pretty astounding accuracy over that period of time. I suppose they said it did not matter for most of the time of human civilization— with only the past several centuries with world population large enough to cause the loss of trees.
The study is a worthwhile read.