"Sam Carana" is not a real person. The name is suspected as being a front for a collective of bloggers with unspecified qualifications and experience. This prevents people with opposing views - including the AGW/CC denialist community - from attacking the credentials and qualifications of the anonymous authors. Better to be challenged and be forced defend one's position rather than hiding behind anonymity. Many who support the non-person "Sam Carana Collective" also disparage scientific peer-review - just like the denialists.
You should refer to that source as the "Sam Carana Collective." Blogging entries and other postings on the internet attributed to "Sam Carana" range from good to idiotic, and you cannot challenge him or her directly, because there is no singular him or her.
The "Sam Carana Collective" response to your tunnels proposal is vague, without substance and detail, and therefore worthless on it's face. Moving heat around does not solve the problem of massive amounts of heat entering the earth's biosphere.
Do you plan to subject the regulars at the ASI blog to the same non-scientific, non-engineered idiotic blather and claptrap that got you perma-banned from commenting Wunderground blogs?
AGW/CC is a serious problem. Those studying its science and political aspects don't need the distraction of unsupported, unscientific speculation. Such blather belongs with the tin foil hat groups.