The Government's being urged to decrease the number of carbon credits available to buy after four failed auctions last year. 

The Climate Change Commission says there are too many credits on offer, and the problem is getting worse. 

It also says the Government needs to clarify their plan for meeting climate targets. 

Climate Change Commission chair Rod Carr told Mike Hosking that there are enough units existing, so fewer are needed to be auctioned in the next four years. 

He says the auctions only occur when there's a need, and last year participants already held units or bought them from secondary markets. 

The Government's next auction is next Wednesday. 

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