‘The time lag occurs because rising air temperatures take time to make themselves felt throughout the immense thermal mass of the oceans. This "thermal inertia" means that Earth has not yet felt the full effect of today's level of greenhouse gases’.
Thermal inertia means that sea level changes will occur even if greenhouse gas emissions are drastically cut. This is quite apart from time-to-build issues involved in constructing new power generation technologies and in making investments to adapt to sea level changes and other consequences of climatic shift.
There are also cognitive lags in the brain-functioning of the denialist camp. The need for anticipatory policies has been extensively discussed in the climate change literature.
One wonders what Ross McKitrick is on about – these lagged effects have been discussed for years.