Carbon pollution imposes costs already by affecting the climate. Those costs are not currently included in the cost of production.  Why not? It's called an 'externality'.

A carbon tax brings those costs back to the producer of the carbon pollution which they will pass along in their cost of product to consumers.  This is a good thing. The consumer can make a more intelligent choice about the value of the product taking into account the pollution costs. 

All in favour of market solutions to allocate scare resources optimally when such opportunities are available say 'aye!'  All others please proceed to the 'regulation' option.