Gnostic
Mark Ella (57)
The last one was preety quick and no man/women about to cause it just a stray rock.
And the odd are that sooner or later that event will recur.
What is at debate here isn't to do with "natural" or "unavoidable" changes to climate and environment. It is purely to do with human impacts.
It is a narrow view and an uneducated one to think that the climate/environment will/should be static and there will be no natural extinction (in my point above). Just without taking into account external inputs the drift of continents will result in major climate shifts over periods of geological time, with those changes unmeasurable at the start but likely to build and reach a tipping point with rapid (relatively) change at some point.
Now add in external/variable factors such as volcanic and solar activity and you get a picture of a relatively volatile climate/environment.
What is the point of the this whole thread is the fact that the inputs from humans in addition to everything else is driving change to rates never seen before (excluding your space rock). With such rates of change evolution is pushed into overdrive and species adapt very quickly to survive. The highly specialised species quickly drop off and only those who like humans can that can adapt to all environments (or adapt the environment to them) survive.
Now lets add to the equation in purely impacts upon humans (not the other way around). Putting aside the displacement due to loss of habitable lands etc. as an example of what a changing climate will mean, this year the government and AMA admitted that a man in Brisbane had contracted Malaria without ever leaving the city. This was reported as the first proven case of this formerly tropical disease so far south.