Billions of trees are being cut down every year as new research suggests that there is an estimated three trillion trees left on Earth. Although it’s more than the previous estimate of 400 billion trees worldwide, it’s trillions less than there used to be, a new assessment has found.
A 15-nation team, led by Yale University researchers, used tree density information from forests around the world along with satellite imagery and super-computer technology to map tree populations worldwide at the square-kilometer level. The results were much higher than expected.
"Trees are among the most prominent and critical organisms on Earth, yet we are only recently beginning to comprehend their global extent and distribution," lead author Thomas Crowther, post-doctoral fellow at Yale School of Forestry and Environmental Studies, said in a statement.
"They store huge amounts of carbon, are essential for the cycling of nutrients, for water and air quality, and for countless human services," he added.
"Yet you ask people to estimate, within an order of magnitude, how many trees there are and they don't know where to begin. I don't know what I would have guessed, but I was certainly surprised to find that we were talking about trillions."
According to the research, the highest densities of trees are found in the boreal forests in the sub-arctic regions of Russia, Scandinavia and North America, but the largest forest areas are in the tropics, which are home to about 43 percent of the world's trees population.
The information on the population of trees will help scientists to better understand the effects of climate change, the distribution of animal and plant species in the world and how trees shape their environments, the researchers said.
The researcher team’s calculations revealed that of all the factors impacting tree numbers, human activity had by far the biggest effect across the world. Due to deforestation, land-use policies and forest management policies, over 15 billion trees are being cut down each year. In fact, the study concludes that the global number of trees has fallen by roughly 46 percent since humans began to clear land to plant seeds.
It is estimated that prior to human civilization, Earth had an estimated 5.6 trillion trees, the numbers suggest that the population of trees on Earth have decreased by almost half.
“We’ve nearly halved the number of trees on the planet, and we’ve seen the impacts on climate and human health as a result,” says Crowther.
“This study highlights how much more effort is needed if we are to restore healthy forests worldwide.”
A side from offering oxygen, fuel and shelter, trees store important quantities of carbon, when released it contributes to global warming.