There is no moral highground when it comes to emission trading, in other words, selling thin air already belong to the world, to put food on the table without lifting a finger is rubbing the poor.
There is nothing wrong with global warming, the scientific facts been distorted to sell things people already got - that is you own it.
A combination of earth axial tilt and sunspot cycle as well as solar flares been the interval of climate change during the Holocene, next major solar flare likely in 2012, tree-ring evidence indicate drought period on part of the earth within the cycle.
We should look at pollution to water source, sea, air (acid rain) to help the world, not selling more pollution. When CFCs was a problem, CFCs emission trading was not on the agenda.
Global warming actually improve global agriculture variability towards the Holocene climates 11,500 years BP to the present, and had sustained the growth and development of modern society.
Holocene climate optimum periods roughly in the intervals of 9000 to 5000 years BP, or before the 1950-based radiocarbon dating reference time scale of paleoecology digs and DNA.
During Holocene climates, increased rainfalls facilitate the development of agriculture, village communities, and eventually cities by human-kind in all part of the world.
Holocene climates in south-western part of North America, the Mediterranean, Middle East, Ukraine, India and China, as well as northern Africa all received more rainfalls than they do today.
Thus Sahara desert than was a lush Savannah punctuated with rivers and lakes that supported life and human domesticated cattle, and later culture as well as agriculture spread into Europe.
Source: Holocene climate variability
<a href="http://www.soes.soton.ac.uk/staff/ejr/Rohling-papers/2004-Mayewski%20et%20al%20Holocene%20climate%20variability%20QR62.pdf">
Holocene climate variability</a>