My uncle (another ST rider, was at the Esk RTE) is pretty high up in Brisbane Forest Park management and has been working on the co-ordination of the backburning over the past few weeks around Brisbane. The issue is that it's a fine line to walk between a successful burn and a wildfire. These guys have been battling bureacracy for years and only recently have been getting some ability to do controlled burns. They're all smart blokes with up to 40+ years experience.
You can't just burn anytime because if the conditions aren't right (eg. humidity too high) the fire won't spread properly and will take too much work to keep going. So too if it's too dry then it can get out of hand. It's a very scientific strategic process worked out in collaboration with the weather bureau and the fireys.
Certain sections of society think all fire is bad, and don't realise that Australia has been managed by fire for 40 000+ years. Unfortunately it all burns eventually (lightning, pyros etc.) and if it hasn't been burned in a while it goes up like a bomb and people die.
