According to the foodtank

The Australian brewery Young Henrys is working to fight climate change with an unusual ingredient—algae. The fermentation process that occurs during beer production releases massive amounts of carbon dioxide (CO2), which can contribute to climate change.

It takes a tree approximately two days to absorb the CO2 released from producing one six pack of beer. But, Young Henrys says their in-house cultivated algae not only absorb the CO2 released, they also produce as much oxygen as two and half acres of wilderness..

Read more at source: foodtank