Global Cooling (???)

I recently read an article in Economist. A scientist Govindaswamy Bala from Lawrence Livermore National Laboratory, California, had proved that cutting down trees will actually cool the planet. The reasons are

1. Trees are dark, which aborbs more light and which inturn heats up land and consumes more underground water through transpiration

2. Bare lands causes more carbon di oxide which forms layer in the atmosphere which is thicker than current air which reflects sun heat making earth cool.

But where will we get the oxygen to breathe? may be we have to start our own photosynthesis.