Scientific evidence indicates that the co2 added to the air by
the burning of wood and fossil fuels is

contributing to global
warming, a rise in global temperature. tropical rain forests are

estimated to be responsible for approximately 20% of global

photosynthesis, yet the consumption of large amounts of co2

by living trees is thought to make little or no net contribution

to reduction of global warming. why might this be? (hint:

what processes in both living and dead trees produce co2? )