Around 30% of our planet is covered in trees. Trees are majestic help biodiversity and can reduce climate change. But we're cutting them down at an alarming rate. Since the start of human civilisation, it's estimated that we've cut down almost half the trees on Earth. So, what would happen if all of us and that's all 7.7 billion of us, planted a tree? Well, there might be 7.7 billion of us, but it's estimated there are currently over 3 trillion trees on the planet. 7.7 billion more trees would be a valuable step forward. But we'd need to go further to make a really substantial difference to the environment. But we could. In fact, according to one estimate, if we planted 1.2 trillion trees, we'd cancel out a decade's worth of C02 emissions by the time the forests mature. So that's more like 160 trees per person. Trees take carbon dioxide out of the air and release oxygen — making them a natural source of carbon capture. Planting 1.2 trillion more trees could capture up to 100 gigatonnes of C02, on top of the 400 gigatonnes captured by all our existing trees. Trees planted near the equator can be especially beneficial, as they grow much faster in the warm, wet and humid environment. Let's imagine that happened. In as little as 20 or 30 years, entire woodlands and forests would be established. And in 100 years, these trees would grow and mature, safeguarding habitats that otherwise get cut down. We'd also see a rise in biodiversity as trees get older and start to decompose, because they, along with dead trees, offer a habitat to all kinds of fungi and insects. On top of this, we could see a positive impact to our mental health, as studies have shown trees can lower stress and make people happier.