Do the world a favour, take it out of the shed and use it instead of burning. The product makes a great mulch which will improve your soil over time, and although it will eventually break down and release CO2 it will take a lot longer and will be a lot cleaner without all those smoke particulates. I guess where you live is not densely inhabited, but the world is a finite place, and the effects of global warming in terms of tornadoes and floods are already making themselves felt.
I have just been reading a book called 'How bad are bananas? The carbon footprint of everything' by Mike Berners-Lee (Tim's brother). Not just informative, amusing and well written as well, though not the sort of book you sit down and read in one go.