emissions trading set for failure.

[king1]

Houses go to auction all the time and don't sell - it doesn't mean the housing market is 'set for failure' .  Nothing is failing...

Why would anyone want to purchase it?
I see it as a liability more than anything!

The reason its set for failure is the time it takes for these millions of trees to absorb carbon, while at the same time its only absorbing a drop in the bucket of a days worth of global CO2 emissions.
People are deluded, do they really think that they can keep burning CO2 because they own some credits in forest?
You would have to be planting the same amount of trees worth of carbon at the same rate you are burning the stuff, and that's just to remain status quo, its not going to reverse any climate impacts, and we are still burning CO2 left right and centre.

Its just greenwashing, just a way to make people feel better like they are doing something meaningful.

it's purpose is to build in a very real cost for businesses and industries that generate CO2, and conversely reward those businesses and industries that sequester CO2.  

It creates a financial incentive on both sides of the equation.  Not a be all and end all solution, but simply a means of modifying behaviours