We use the term "denial" when is applies to a set of strategies to deny accepted science and sow unwarranted doubt. I find there is a range among those who dissent from the AGW consensus, but at one end of the spectrum there are certainly deniers, and I think Heartland fits into that category.
The use of the term on this podcast is quite pejorative, and intentionally so. Despite the rantings of Rebecca, whose scientific credentials are

??, there are plenty of legitimate concerns, both scientific and ethical, with the AGW lobby.
On this podcast the term is used for Orwellian effect, in an attempt to stigmatize one side of a legitimate debate.
This podcast seems to forget that AGW science is largely not in the realm of observational science, but instead relies on complex, esoteric computer models and simulations, which ultimately are as subjective as the designer's biases.
To date, 95% of the IPCCs models have been wildly off the mark, to the high side. When 95% of the model error is in the same direction, it should give any reasonable observer pause to question the priors of the researchers.
Welcome to what Steve calls "denialism." I always thought that science rested on testable predictions. When those predictions are incorrect 95% of the time we now call it "denialism."
Orwellian indeed.