The increase in human population and deforestation has wiped out 46% of the Earth’s total trees since the dawn of human civilization. But still there are a whopping 3 trillion trees on our planet, according to an extensive study conducted by researchers at the Yale University. It works out to roughly 422 per human being. Findings of the study were published in the journal Nature.
We need to comprehend the extent and distribution of trees
The new estimate is more than seven times higher than a previous estimate of 400 billion trees on the planet. Scientists led by Thomas Crowther utilized previous peer-reviewed studies, satellite images, supercomputer technologies, and density information from 429,775 forest plots across the globe to reach the figure of 3 trillion.
Trees are one of the most prominent organisms on our planet. But we have begun to comprehend their extent and distribution only recently, said Crowther. Scientists conducted the study upon a request by Plant for the Planet, an international youth initiative that leads the “Billion Tree Campaign.” A previous study had concluded that there were 400 billion trees, roughly 61 per person, worldly.
Human activity eliminating 15 billion trees every year
Why was there such a huge difference in the estimates of Crowther and the past study? Because the old one’s estimate was based on satellite imagery and forest area. While satellite images can reveal what areas of Earth are covered with forests, they cannot see individual trees. Crowther and his colleagues also relied on peer-reviewed studies and information from national forest inventories. Each of them included tree counts that had been verified at the ground level.
They found that the tree population density was highest in the sub-Arctic regions of Russia, Europe, and North America. However, by far the largest tree areas are in the tropics, home to 43% of the world’s tree population. Researchers said that human activity was directly responsible for the loss of 15 billion additional trees every year. Crowther said we have almost halved the number of trees on the planet, and we have begun to see its impact on human health and the climate.