I can imagine a Carbon Tax. Someone says for every ton of pollution you emit you pay the govt. $50. We can imagine what could be done with that.
Carbon trading means, I think, a company or industry has a capped amount of said pollution, say 100 tons, if the industry lowers its pollution say by ten ton, they sell the ten tons worth of value to someone who has exceeded their cap?
Will there be profit in buying credits to pollute?
The brokers of the scheme are who? How much will their commision be will it be private, the stock exchange for example.
Will it be as water is, traders with a mobile phone?
I have so many ?/s can anyone "please explain"
fluff

What do the IPCC group mean when they claim 90 % certainty? I have not read the full report (which I understand is not yet in the public domain). So this is my guess:

In statistical hypothesis testing, the conventional level of significance is p =.05 or less. This means that the chance of being wrong, that is in claiming a positive difference from the null hypothesis (in this case no global warming) is 1 in 20 or less.

Some times stricter criteria are used say 1 in 100 or p=.01. Again an argument can sometimes be made for a lax criteria p=0.1 or 1 in 10.

A possible reason for choosing a lax criterion is that the corresponding 90% confidence interval is narrower. The meaning of a confidence interval is that the expected result has a 90% chance of being in the interval. A narrow interval means greater precision at the expense of some loss of accuracy.

Conversely if the claim is made that the global warming will be in the range of .01C upwards to infinity, the statement would be very accurate. However, the precision attached to the prediction is so poor, as to be in practice valueless.

Another thing does anybody know if IPCC is using one or two tailed tests. A one tailed is less demanding. The justification for using a one tailed test is a conviction of certainty that the direction of change can be in one direction only. That is in the direction of warming. The possibility of global cooling is deemed impossible.

Response to Fluff:

I don't point the finger at corporations for global warming. They should be part of the solution and most are willing to be part of it.

Carbon trading provides a price for carbon, which can be factored into economic decision making. This is the most reliable way of achieving any outcome.

I hate to be negative about a theoretically good idea, but when you get into the guts of carbon trading it just doesn’t stack up.

If it’s going to be meaningful, it needs to include China and indeed the whole world. If China was a part of it, its inevitable rapid expansion in GHG emissions would mean that it would have to be rapidly accruing carbon credits, which it would have to take from the rest of the world. So if there was a set number of credits for the planet, which there would have to be if the scheme was to be meaningful, then we in Australia would be suffering a continuously falling number of credits, or carbon emission units.

The overall number of units would have to be decreasing anyway if we are to progressively and rather quickly reduce global emissions, so the impact of China would accelerate this.

A global scheme is impossible, at least for the foreseeable future. So the next best thing is to set up a national scheme and encourage as many countries as possible to do the same. All those under the Kyoto banner to start with. But even if this is really successful, it would only amount to a small reduction overall, within those countries, and no reduction globally for as long as China bores ahead with its development.

continued

There are too many loopholes which allow carbon to be sequestered while we continue on with business as usual. We could plant huge areas of trees in Australia, and we could factor in the CO2 absorption in the oceans that come under Australian jurisdiction… and basically just continue with our fossil-fuel-driven society practically unhindered, while showing an overall massive reduction in GHG emissions on the books. It all depends just what values are placed on the innumerable variables, such as how much carbon a given area of forest in a given climate on a given soil type is deemed to absorb.

And of course we in Australia and the USA in particular would be doing this within a paradigm of continuously increasing population, economy and industry!

In short, the carbon trading scheme sounds like another dodgy distraction, made out be a big step forwards while we continue to bypass the issue that really matters – our addiction to continuous expansion.

Within a paradigm of no expansion, and preferably of gentle reduction of our overall extent of activities on this continent and planet, carbon trading has merit. But until we get our primitive brains weaned off this primal urge to keep getting bigger, that is until we get serious about developing a holistic sustainability strategy, it is not going to be the answer, or even a significant part of the answer, to our climate change woes.