Geoengineering: Technology of Last Resort?

As a resident of planet earth with children, I have been watching the long, painful public discussions relating to greenhouse gas emissions for decades with a mixture of hope and despair... hope that increasing scientific evidence would galvanize action to address the problem and despair that this is a problem too difficult for human beings to solve before an ecological disaster kills significant numbers.   I have written previously that in the 1980’s one of my colleagues from Harwell Labs had identified this as the most significant threat to human beings and that one solution was to introduce stratospheric aerosols to cool the earth and counteract the effects of additional greenhouse gas in the troposphere.  This concept, now called geoengineering, is getting more serious consideration in technical and policy communities (see for example, http://www.economist.com/node/18175423.)

My current thoughts on the subject:

1. Ecological impact of increased greenhouse gas emissions has already happened, however, most people can’t connect the human causes (fossil fuel burning) with the human effects (crop failures, starvation, population dislocations, war and genocide.)
2. Our current political and economic systems are too local and too short term to adequately address this problem... they have failed us and are not likely to change soon.  Furthermore, it is more cost effective for interested parties to inject noise into the public debate than to change the economic behavior that has created the problem.
3. Independent of whether action is taken or whatever action is taken to reduce emissions, there is enough CO2 in the atmosphere and enough inertia in the economy these consequences will continue for decades or generations.
4. Since we can’t cure the disease, we are then forced to treat the symptoms.
5. The only proposal that can be implemented quickly and cost effectively is a geoengineering solution that creates sufficient cloud cover in the stratosphere to reflect sunlight back into space to counterbalance the greenhouse effect in the troposphere.
6. This is an action that can be taken by a few technologically advanced countries that find it in their best interest to stabilize planetary climate to reduce the cost and risk of the human consequences of greenhouse gas emissions.
7. Although the politics of this solution are difficult, this solution is less difficult than previous attempts to limit emissions.  This will not require most people to change their lives and jobs.
8. Because this is an entirely new technology, there will be a learning curve while cloud creation and control systems are developed.  This will take years to develop, but not decades.  I believe the solution can be developed quickly enough to address the problem.

What are your thoughts on geoengineering?  Are there other approaches to treating the symptoms of global warming that hold more promise?