Carbon offsets

What do you think about the idea of "carbon offsets"?

I have been doing some reading up on this, and this site contains some real concerns:

http://www.foe.org.au/campaigns/climate-justice/issues/climate-change-briefing/carbon-offsets/?searchterm=neutral

Quote:

Carbon offset companies are unregulated. There is no watchdog to check how they spend your money. They create the illusion that by paying a small amount of money to 'offset' our emissions, we can continue our high-consuming lifestyles. This is dangerous as we need to take responsibility to reduce our emissions — we can't shift this responsibility elsewhere. In many situations, scientists do not know how effective trees are in are in absorbing carbon from the atmosphere. While planting trees might be a good thing to do in some contexts, in other situations tree plantations can result in an overall release of emissions. Furthermore, trees generally take many years to grow to a stage where they can significantly absorb carbon, whereas we need to reduce our greenhouse gas emissions now. There's also evidence that tree planting can actually release additional greenhouse gas, as the soil is dug up before planting.

Point (2) really struck home as I have seen the way "carbon offset" advertising goes on - balance your travel to the holiday destination by buying a carbon offset, for example, and hey presto, you are green! The other meaning of green - naive - would seem as appropriate.

As someone who studies odd periods of history, I am struck by the similarity in many ways in terms of "naive belief" to the Chantry Chapels of the Middle Ages, where those who could afford it paid others to do the praying that they could not be bothered to do themselves.

In each case, it is an "invisible" benefit. "Carbon offsets" may be real, but considering the points made above about regulation, it is a ready made market for charlatans, and there is also a justice issue: is it fair that the richer people can "buy" their ability to be environmentally friendly, and continue practicing what a non-green lifestyle, comfortable in the knowledge that someone else is doing it for them (or apparently doing it for them)? Just like the rich in the middle ages, where there was a "sin offset" by paying for chantry masses?