Asteroid impact model the best approach to climate change policy

And a significant portion of that change would have been part of a natural climate cycle coming out of the Little Ice Age that saw widespread famine and disease. So, our contribution to the change that has occurred in those 143 years is something less 1.2 degrees, anything but catastrophic.

Changes in sea level rise and extreme weather have also been unexceptional in the last century. Therefore, like temperature rise, the contribution to these changes from human activity must have been very small.

Anthropogenic climate change worries are based solely on possible future events, events that are, by definition, not yet known. Granted, those changes could be a problem,or  they may not be. Professors Chris Essex (applied mathematician, University of Western Ontario) and Ross McKitrick (economist, University of Guelph) write in their award-winning book Taken by Storm:

Climate is one of the most challenging open problems in modern science. Some knowledgeable scientists believe that the climate problem can never be solved.

Even the IPCC said in its Third Assessment Report:

The climate system is a coupled non-linear chaotic system, and therefore the long-term prediction of future climate states is not possible.

So how does one develop sensible climate change policy when the likelihood of dangerous outcomes is unknown, and perhaps even unknowable?

In his 2004 PhD Thesis, "Astronomical Odds - A Policy Framework for the Cosmic Impact Hazard," Geoffrey S. Sommer laid out a rational hierarchy of responses to the possibility of a catastrophic asteroid or comet impact with our planet, something he considered "an extreme example of a low-probability, high-consequence policy problem." He identified three levels:

Level 1: Survey - Surveillance and tracking.

Level 2: Characterization - determining the characteristics of the object found in level 1.

Level 3: Mitigation - interception (asteroid defense systems, deflection, etc.), civil defense and consequence management after impact (a form of adaptation).

Sommer's approach is similar to that often used in military operations: surveillance is used to detect a threat; the detected threat is then tracked and, to the extent possible, characterized; then mitigation actions are, if deemed necessary, taken to neutralize the threat. Surveillance and tracking provide support for the mitigation function.