Nordhaus and Shellenberger are the darlings of the GW denier set because of their harsh criticism of the "doom and gloom" rhetoric that sometimes emanates from the environmental movement. They'd prefer something more "can-do" and "uplifting". Nevertheless, it is important to note that when it comes to policy prescriptions, they are well within the economic consensus on Global Warming.
For example, it is important to note that in this piece from today's Ottawa Citizen, they are not arguing contra a carbon tax. Rather, they are arguing that a carbon tax like that which the Campbell government has levied in B.C. is not anywhere steep enough to change economic behavior, and therefore the rationale given for it should not be changing economic behavior. Rather, its rationale should be to fund
...technological advances to make clean energy as cheap as possible as quickly as possible. Toward this end, all of the revenues raised from new carbon taxes or auctioning pollution allowances should be dedicated to the research, development and deployment of new technologies that the private energy sector cannot and will not do.
They make reference to Denmark and Norway, a pair of countries that imposed a carbon tax back in the 1990s:
...while Norway uses its revenues for government spending, Denmark earmarks its carbon tax revenues for clean energy, such as wind power, which has become a vibrant national industry. As a consequence, Norway's emissions climbed 43 per cent while Denmark's declined 15 per cent.
Now, as it stands currently, apart from the accelerated capital cost allowance for green technologies, the Federal Liberal Green Shift seems tilted too much towards the Norwegian, and too little towards the Danish model, for my tastes. But Dion is apparently big on listening, so perhaps that will change.