How does deforestation increase greenhouse gases?

Basically, tree's body is a storage of Carbone "C"... when forest grows, it takes Carbone from the CO2 and release O2.

So it produce O2 and decrease CO2 WHEN IT GROWS.

if you cut a tree to make furnitures, you dont release any C in the atmosphere, but you reduce the forest's size that then can grow again.

Small trees grow faster than large ones therefore they consume more carbone.

As a result, by doing deforestation and using the wood, you decrease CO2 concentration.