|Earth has lost half its trees because of humans
There is good and bad news about trees. The good news is there are seven times more than we thought. Scientists thought we had 400 billion trees, but we have three trillion. That's a three followed by 12 zeroes. For each person alive today, there are 420 trees. A researcher said these numbers were not good or bad news.
The bad news is that we once had six trillion trees. We lost three trillion trees. Europe was once a giant forest. Now it is fields and cities. Another 15 billion trees are lost each year. This is a lot more than 100 years ago. The researcher said we must do more to make forests healthy again.