The technical know how of you guys is truly impressive. But conceptually the entire discussion is similar to a bus full of people heading for a cliff at accellerating speed and the excited chatter amoungst the passengers is about the distance to the cliff, what it will be like when the cliff is reached, would it be possible to move the cliff, is the path to the cliff an uphill slope or a down hill slope, should the guy who talked about putting on the brakes be thrown off the bus or just be sat upon, the price of the bus fare, etc.

There was figure that I read somewhere that suggested that an area the size of Minnesota (225,000 sq klms) would produce sufficient oil from algae to supply the entire world's oil needs daily. Now assuming that this is even vaguely true, and recognising that all of the oil that we are consuming now was produced by algae over millions of years, many millions of years ago, you would have to recognise how flukey it is that there has been enough oil captured geologically to keep our oil powered civilisation going for just 150 years. Where is the end of this road? where is the cliff? We know that it is not more than a hundred years away.

It would be nice to see a percentage of the phenomenal collective intellect of TOD directed positively towards what the next phase of our energy march will be. No responsible oil man would run his well dry before he started the search for a new field. So that is what should be happening here. Our collective oil well is in decline. There should be an increasingly determined search underway for our next energy field.

BilBb
2 quick questions:

1) Next phase of energy march for 'who'? All 6.8 billion plus their descendants? Or some fraction thereof?
2)If/when we find the next energy field, shouldn't we also consider the non-energy limiting inputs required for the energy? Land, water, soil, minerals etc? Energy is key. But it's not the only thing we are approaching limits on

a bus full of people heading for a cliff at accellerating speed

Do you agree that the first thing to do would be to take your foot off the accelerator?

That's how I see politics right now. One party (we'll call them the "red" team) just wants to keep accelerating. The other (the "blue" team) wants to pick up passengers first, and then accelerate off the cliff.

There was figure that I read somewhere that suggested that an area the size of Minnesota (225,000 sq klms) would produce sufficient oil from algae to supply the entire world's oil needs daily.

Well, Minnesota is half covered in lakes, so you could test that now.

Using a solar insolation table for MN:

http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/sum2/14922.txt

the total solar energy hitting the ground annually can be calculated. I come up with about 1.4 times the energy in the total annual oil usage. But then the discounting begins. It's too cold for anything to grow much of the year, photosynthesis isn't all that efficient (much less than PV) at creating stored energy, and the earth is really, really lousy at keeping the energy from degrading over the years. We're just lucky it was concentrated by gravity (oil being lighter than water).

Similarly, the Ogallala Aquifer was charged up over millions of years. How could we possibly deplete it in 100?

No responsible oil man would run his well dry before he started the search for a new field.

Perhaps not, but many a pragmatic oil man would just take his money and get out of oil.

Pickens?

Our collective oil well is in decline. There should be an increasingly determined search underway for our next energy field.

But what if there isn't a "next energy field", at least on the scale needed to replace hydrocarbons? Then "increasing determination" will only put us further in the ditch.

That's the next big debate IMO. Peak or near peak is baked. What's still in the oven: is there ANY source of energy that can replace on the necessary scale?

If not, we must retrench, starting yesterday.

Necessary scale:

- Amount of power produced after accommodating EROEI (assume some conservation)
- Resource availability for buildout (material and financial)
- Political / social will

Next to totoneila's wheelbarrow, I suggest some sandbags and a good shovel. Stops bullets, stops floods, grows potatoes, and it's great exercise.

Good comment, you got me thinking.

Where we know we need to retrench is in the size of our ecological footprint. We need to use less water, soil, pollute less, and in general put less stress on the natural systems which provide the ecological services that enable us to be here. I think the big questions are 1) how much do we need to reduce this footprint and 2) how much net energy will we have after this reduction, especially when you consider that as high quality fossil fuels deplete, use of lower quality fossil fuels will increase not decrease our collective footprint.

A better question to decide before "size of new ecological footprint" is "what will be the limiting mechanism used?" Access to money, government military force, etc. etc.

Decide that first, thn I might take a shot at your question.

My vote would be for mutual agreement enforced through overwhelming ostracism for violators. In much the same way that some here think SUVs will eventually go away because excessive consumption will become socially intolerable. As I think you are suggesting, nothing else would be fair.

In that case I'll guess that the future ecological footprint will be "as large as available finances will allow", in other words financial / market constraint. Worst case, actually.

But this doesn't answer the question of how much strain our natural world can withstand. In my mind that is what needs to be answered. Or at least answered with a Bayesian response since it is unlikely that there is a single knowable answer.