From Jim McHardy, Clydebank, West Dunbartonshire, UK
Drilling through polar ice to pump out liquid water from beneath won’t work for several reasons that weren’t mentioned. At the depths and temperatures of the buried water, it is close to the equilibrium between being ice or water. A slight change could drive it either way. Water, whether in an artesian well or pumped up, may freeze in a borehole as it rises and the pressure reduces. Also, ice flows under pressure, so the borehole would have to be steel lined and would eventually shear and seal up, possibly before completion(20 September, p 20).
Another geoengineering idea, a huge orbiting parasol, would be a sight to behold from the ground, but would need to be tilted side on as it passed over countries that weren’t in favour of darkness at midday for all sorts of reasons. Huge louvres on a space venetian blind might be better.
