Didn't the planet survive those mass extinctions? Didn't life return to normal? Killing the planet means ALL life is gone.
That is a pretty low bar to set on this subject!
For what it's worth, some paleontologists who have specialized in the Big One -- the Permian/Triassic Extinction 250 million years ago
(Peter D. Ward - Under A Green Sky 2007) tell us that it got pretty damn close to destroying all complex, multicellular life back then. If you are demanding that every bacteria and virus be incinerated also, that's an absurd standard to uphold.
I mentioned on another thread that the journey of life on Earth from the first one-celled animals to the first multicellular life took 2 billion years. That indicates that complex life is not as adaptable to extreme environments. If we look at the natural geologic changes that will occur over the next couple of billion years (as well as the Sun) if such a catastrophic extinction occurred today, there would be no re-building; and Earth would remain an abode for bacteria until it was absorbed by a Sun turning into a red giant star in the distant future.
At the end of the Permian...before disaster struck...life was becoming increasingly complex and diversified. Our ancestors - referred to as mammal-like reptiles (Synapsids), mostly went extinct, and we wouldn't be hear to discuss it if they were all wiped out!
After the long term volcanic activity, caused by plate tectonics started to recede, the oceans and the atmosphere were able to recover and allow life to flourish again. The first out of the blocks, were the ancestors of the Dinosaurs, which became the dominant species for over 180 million years. Our ancestors - the mammals, were there all through the Age Of Reptiles, but had to eke out an existence mostly underground in the shadows, as the Dinosaurs dominated all of the ecological niches on the planet.
And then, as we are all well aware now, an extinction 63 million years ago ended the Dinosaur's reign and allowed the Mammals to take over the planet and diversify, and become the dominant group on animals on the planet.
The first thing that comes to mind after a brief snapshot look at previous extinctions (there were other, smaller extinctions within those five) is 'what if the P/T Extinction never happened? Our ancestors were doing pretty well 250 million years ago, before the Dinosaurs took over and disappeared. The Mesozoic Eras -- Age of Dinosaurs, can be viewed as an interruption of what could have been -- some sort of intelligent mammal species with opposable thumbs creating a civilization hundreds of millions of years ago!
For me, this is nail in the coffin for concepts of intelligent design, progressive evolution, or any cavalier notion about planetary extinctions being regular and acceptable events in Earth's history.
I did not say that militant environmentalists are the problem, I said they confuse the issue by exaggerating the problems with pseudofacts and out right lies. This makes them no better than the head stuck in the sand types who ignore the good science just because some fanatic was caught in a lie. My point is keep a cool head and stick to the real facts. In other words, Moderates Rule! heh heh.
No, I would say that moderates don't rule under circumstances that call for drastic action as quickly as possible! We are heading into a perfect storm of looming disasters:
world agricultural production has plateaued and is receding right at a time when the population has been allowed to hit 7 billion and will continue to increase further....if it is able to...not likely though for a number of reasons! The two major roadblocks to increasing population are a decline in fresh water availability across most of the world, especially in the temperate and tropical zones with the highest populations; and the loss of topsoil from modern intensive agriculture.
We have used up over half of the Earth's petroleum reserves that were in the ground (90% has been used in just the last 50 years), leaving a global economy that continues to be based on oil to dig deeper or refine the dirtiest, most carbon-intensive oil reserves (tar sands and shales)....bad news for that energy-intensive system of agriculture we have developed over the last 50 years, which is the only reason why the Earth's population has managed to reach present levels in the first place.
There is even a threat to civilization as we know it, being presented by a steady decline in ore grades, as well as the increasingly lucrative rare-earth minerals. One of the great undiscussed subjects today is that iron, copper, silver, gold, you name it -- every metal that is used for making stuff is in decline -- which means that more digging and refining is needed to get the same amount of ore from the rocks, and adding more energy, time and labour to the process.
Mines do not all of a sudden run out of ores or minerals. As with oil, the percentage of metal keeps declining as the digging continues, until it reaches a point where the costs of extraction outweigh the benefits, and the mine becomes obsolete. As metal prices continue to increase, the mines keep digging further, using more energy for extraction and refining.
There are other looming problems threatening the size of present world population, as well as our modern, high energy and resource intensive way of life, but this will do for now. If I believed that there were "moderate" ways to get out of a looming disaster, I would be all for them! But, I don't see any way forward as long as we are living the way we are right now.
You should see me crabby.
