A recent essay at The Survival Acres blog touches on many of the terrifying issues that confront us – global warming, peak-oil, overpopulation, the deep degradation of the environment necessary to sustain all life.
If there's any conclusion there, then it would seem to be, "What is going to kill us off first: Global Warming and its consequences for the global food supply that the over-abundant human population relies upon, or Peak Oil and the resulting collapse – starting potentially within 2 to 6 years – of industrial/technical society?" Either way, the results would seem to be eerily similar – mass starvation, coupled with lawlessness, roving hordes searching for food, burning the last of the trees to keep warm... The stuff of so many D-grade sci-fi movies.
Let anyone who doubts the sort of behaviour outlined above go to a squatter camp anywhere in Africa and count how many trees remain, how much vegetation, how many animals are left.
The heart of the question is, "Is it at all possible to maintain any form of technological society in the face of the impending human disasters before us?" Or are we doomed to a collapse back to Stone Age technologies and Stone Age human population levels – perhaps only a few hundred-thousand human beings on the planet?
The author of Survival Acres seems pessimistic. Or perhaps that's just "realistic".
Perhaps I am just a little too unwilling to give up a fantasy. The fantasy that we can keep something of our modern technological ways. Perhaps even improve on our present society, creating something more humane, more attuned to our needs and the needs of the rest of the ecosphere about us. But we certainly cannot do it at current human population levels, and we certainly cannot do it at First World levels of energy consumption, even assuming much-reduced human numbers.
How many people can the Earth sustain? For a long time the conventional wisdom seems to be that a population of about 1 billion (that's the American "billion" – 1 000 000 000) though recently I have seen some writing suggesting that 2 billion might be sustainable. Personally I doubt the higher figure, but either way we are in for a hell of a ride as the population crashes from the present levels of somewhere betwee 6.5 and 7 billion!
Can we live on much lower energy levels? Certainly! Concensus among experts I have read seems to suggest that the most energy we could reasonably expect to sustainably generate would be around 20% of current First World consumption. (Not sure if this is purely at a household level, or whether it includes the massive industrial and industry-agricultural inputs. Anyone?)
The problem and the challenge is how to manage a transition from our present societal structures and dependence on Big Energy to something that will simultaneously allow us to go forward retaining the good bits of our society (and I would call the Internet one of the Good Bits) whilst also surviving the terrible, tragic process that surely faces us.