Carbon taxes are imperfect solutions because you don't where to set the tax at. A good cap and trade market will find the right price, and even better, it should use the same price to compensate people for building carbon sinks, ie. planting trees, etc.

It's really unlikely we can get anywhere near the reductions we need simply by limiting carbon emissions, returning lots of carbon from the air into sinks likely can be far cheaper than stopping the last X% of emissions.