How many acres of trees each year are needed to off set the 60 billions tons of co2 produced each year?

It's not that simple. Trees also produce carbon dioxide through respiration so they're not as good at reducing CO2 as you like to preach. Also, we mustn't remove all the CO2 we produce as having a decent amount of CO2 in the atmosphere is necessary for life. In addition, most CO2 is removed from the atmosphere from algae and phytoplankton in the sea, we should be more worried about them.