Earth's Trees
A new study authored by Thomas Crowther of Yale University has estimated that there are three trillion trees on earth; far surpassing the previous estimate of 400 billion trees. Crowther and his team used ground survey data (such as National forest inventories) and satellite pictures to produce a model that predicted the number. This model generated 1.39 trillion trees in the tropics, 0.61 trillion in temperate areas and 0.74 trillion in boreal forests. Using this data they were also able to estimate that in the past 11,000 years, humans have removed 3 trillion trees. Currently, the rate of removal (for timber, land use conversion and agriculture, etc.) is estimated to be 15 billion trees per year, with 5 billion replanted each year.
~SA
Image: http://bit.ly/1EJVE7z by Scott Wylie Paper: http://bit.ly/1EJVMUJ