OK, that's a challenge that I cannot resist. My first reaction is that if we are going to contemplate such a large project, we must in any case start off right. That means doing due diligence "at the front end". This in turn means doing our research and analysis with a view to developing a Business Case. I love Business Cases because in my experience they garner significant amounts of useful information and analysis, but rarely get properly implemented or followed because the sponsors are far too keen to start implementation regardless.
In broad strokes, here is what such a climate change project Business Case should include:
Proposed scope: What does this project actually involve, what would it look like?
Justification: What, why, how, and how much should be involved? What are the measureable benefits and risks? What would be the cost and would it be worth it?
Base Case: What is today's documented status to be referenced for purposes of determining actual achievements to be measured at some time in the future? What assumptions does this require?
Alternatives: If any, including no effective action (the most likely), and corresponding assumptions?
Implementation: Strategy, Key Success Indicators, resources involved, tentative schedule, cost estimate, source of funding and implementation risks;
Approvals: Roster of Stakeholders (participants).
With all the political hype and blather, has anyone actually looked at any of these issues? Probably not, so here goes.
3. Data extracted from Issacon #1208b at maxwideman.com/issacons2/iac1208b/sld005.htm