More on the geo-hacking idea

Not so long ago I posted about the idea of capturing all the extra atmospheric CO2 into the worlds oceans by fertilising them and thereby creating enormous plantkon blooms that would convert all the CO2 to plant tissues, which would then sink to the bottom and be buried in the ocean depths.  This new scientist article probes a different angle that I didn't think of, which is Who decides what we will or won't do to change these things?  The author Jim Giles refers not just to ocean fertilising, but engineering the whole planet to combat climate change - what has become popularly known as "geo-hacking" - including sensible concepts like reforestation and cloud seeding, as well as the more absurd notions such as building giant reflectors to bounce the sunlight away.  Its a thought provoking question, so who do you think should decide these issues?  The US? UN? UNESCO?  Perhaps we need a new body with that as its sole charter?