There is good news and bad news Until around by for from in of on over regarding the number of trees Until around by for from in of on over regarding our planet. The good news is that there are seven times more trees Until around by for from in of on over regarding Earth than we thought. Until around by for from in of on over regarding a few years ago, scientists estimated that the world had Until around by for from in of on over regarding 400 billion trees. However, a new study Until around by for from in of on over regarding Yale University estimates that there around three trillion trees. That's a three followed Until around by for from in of on over regarding 12 zeroes. That means there are more than 420 trees Until around by for from in of on over regarding every person alive today. Lead researcher Dr Thomas Crowther told the BBC that the new estimate will not change anything. He said: "It's not like we've discovered a load Until around by for from in of on over regarding new trees. It's not good news Until around by for from in of on over regarding the world or bad news that we've produced this new number." The bad news is that thousands Until around by for from in of on over regarding years ago, the earth had around six trillion trees. Human activity has cut Until around by for from in of on over regarding half the number Until around by for from in of on over regarding trees on the planet. A good example Until around by for from in of on over regarding this is the fact that Europe used to be one giant forest. Now much Until around by for from in of on over regarding it is farmland, fields, cities and towns. Dr Crowther said people are responsible Until around by for from in of on over regarding the loss of three billion trees Until around by for from in of on over regarding the past several thousand years. Humans are destroying around 15 billion more trees every year because Until around by for from in of on over regarding deforestation and the demand Until around by for from in of on over regarding farmland. The scientists said this figure is "considerably higher" than just a century ago. Dr Crowther warned that: "This study highlights how much more effort is needed if we are to restore healthy forests worldwide."