I see that William Kininmonth is still arguing in The Age that a cut in human-caused carbon dioxide emissions will have little impact on the future climate as the effect of carbon dioxide increase is relatively small in the context of the internal variability of the natural climate system. That is a justification for the do nothing option.

Tandberg

As Stuart White and Chris Riedy argue in the Sydney Morning Herald:

The largest, cheapest and quickest component of that sustainable energy future will be improving the energy efficiency of existing and new households, businesses and industries.Improving energy efficiency simply means doing better with less energy, through the use of improved or "smarter" design, appliances, equipment and energy-using practices. This will be the unsung hero of the future, despite the attention being paid to high-profile, high-cost options such as "clean coal".