Environmental scientist David Keith talks about a cheap, effective, shocking solution to climate change: What if we injected a huge cloud of ash into the atmosphere, to deflect sunlight and heat? As an emergency measure to slow a melting ice cap, it could work. Keith discusses why it's a good idea, why it's a terrible one -- and who, despite the cost, might be tempted to use it.
Keith addresses the geo-engineering option with unnerving finesse. My prediction is that someone -- whether an international agency or a single nation -- will opt for a geo-engineering quick "fix" before long before emission reduction alone can curb rising temperatures.
Think of it as choosing to use a nuclear weapon; it's not an easy decision, but when the situation is sufficiently dire there are always those ready to make it.