Some of the major extinctions have resulted in well over 90% species loss. Reading some views...Lovelock, Lynas etc, we may be looking at a major extinction. Our brain power and technical development does give us something special, but on the other hand, the larger and more complex organisms are always the most vulnerable. In a way it is academic whether the human species survives or suffers 99.999% population loss. The suffering we will have created both in our own species and many others will be incalculable. Extinctions will happen, but this one will be the responsibility of one species uniquely with self consciousness and the intelligence to know it is coming. We know, and we are not acting effectively...perhaps it is better that a species which behaves like that does suffer extinction?