We need to stop any net increase in emissions within five to ten years and then to bring emissions down.
At present there seems little chance of us meeting this demanding target. But there will come a point (perhaps after 2018) at which the key players - the governments of the US and China - recognise the need for action. At that point they will combine to insist on a world response. If it's too late to handle the growth in emissions then geo-engineering may be the only option. (http://www.ted.com/index.php/talks/david_keith_s_surprising_ideas_on_climate_change.html)
Several geo-engineering schemes have been proposed. Some obstruct incoming sunlight or reflect it back whilst others collect CO2 from the atmosphere and store it underground. All will be very expensive and will be required in addition to, not in place of, energy efficiency, reductions in aviation, renewable power generation, etc.
Most geo-engineering schemes will have significant side effects, eg they may warm some areas whilst cooling others. Inevitably there will be winners and losers. So what's needed is:
- First, honesty about the possibility that our current efforts will fail.
- Second, real R&D on geo-engineering schemes and their likely costs and effects.
- Third, study of the forms of governance that such schemes will need.
But that is not what we are likely to get. In her book The Shock Doctrine Naomi Klein has shown how the US government and major international organisations, especially the IMF, have used a series of crises, eg Iraq, the asian tsunami, New Orleans, to advance a neoconservative political agenda. Indeed, in some cases, and not just in Iraq, they have deliberately created the crises.
The effects of these political interventions have been to increase enrich certain major corporations whilst increasing violence, corruption, sectarianism and the gaps between rich and poor. More to my point - the proportion of the money spent that has produced real benefits on the ground has been astonishingly small.
These interventions - driven by an unholy alliance of China and the US - would constitute a big step towards the Police World scenario.
The neocons have been able to achieve these perverse effects because of their strong position - control of the US government is a big advantage - and because they have been always ready to propose - indeed impose - their preferred solutions. The challenge for people of goodwill is therefore to think through what's really needed before panic induces governments to adopt simplistic and counter-productive solutions.