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Over 3 Trillion trees currently thrive on Earth: Study

TREES There are roughly 3 trillion trees on Earth more than seven times the number previously estimated according to a tally by an international team of scientists. The study also finds that human activity is detrimental to tree abundance worldwide. Around 15 billion trees are cut down each year, the researchers estimate; since the onset of agriculture about 12,000 years ago, the number of trees worldwide has dropped by 46%.

Out of 3 trillion trees, approximately 1.39 trillion exist in tropical and subtropical forests, with 0.74 trillion in boreal regions and 0.61 trillion in temperate regions. Based on projected tree densities, it is estimated that over 15 billion trees are cut down each year. That is a net loss of 10 billion trees a year. At that rate, all of Earth's trees will be gone in about 300 years. The global number of trees has fallen by approximately 46 percent since the start of human civilization. Before human civilization, Earth had about 5.6 trillion trees. The Biome-level trends in tree density demonstrate the importance of climate and topography in controlling local tree densities at finer scales.

The previously accepted estimate of the world’s tree population, about 400 billion, was based mostly on satellite imagery. Although remote imaging reveals a lot about where forests are, it does not provide the same level of resolution that a person counting trunks would achieve.

Crowther and his colleagues merged these approaches by first gathering data for every continent except Antarctica from various existing ground-based counts covering about 430,000 hectares. These counts allowed them to improve tree-density estimates from satellite imagery. Then the researchers applied those density estimates to areas that lack good ground inventories. For example, survey data from forests in Canada and northern Europe were used to revise estimates from satellite imagery for similar forests in remote parts of Russia.