The latest technology has allowed scientists to discover that logging is destroying the Amazon rainforest twice as fast as they had feared.
It was already known that 5,800 square miles of the forest was disappearing due to cattle ranching and farming.
But satellite technology has revealed that up to a further 8,000 square miles are being lost to "selective logging".
This is when certain trees like mahogany are cut down because the loggers can get a lot of cash for them.
Until now, the damage had been largely hidden because scientists did not have the tools to look beneath the forest canopy.
The tractors used by the loggers and the dirt tracks they create are also harming the forest.
Pulling up the trees also affects other plants and the branches and other debris left behind decompose, releasing carbon dioxide into the atmosphere and contributing to climate change.