Thanks Jonathan. (As of 2012, I understand atmospheric CO2 is ~400 ppm, not 390 ppm).

If methane's warming potential is 70 times that of CO2, then 1770 ppb of methane is roughly equivalent to a further 124 ppm of CO2. (From Wikipedia, pre-Industrial methane may have been ~700 ppb). What's more, even if that methane only has an atmospheric lifetime of 20 years, bear in mind that methane is being emitted at ever-increasing rates from thawing Arctic sources.

Do you think it plausible that the long-term cooling trend experienced since the Eocene Optimum (so-called) may have been largely the result of carbon sequestration in permafrost and submarine clathrates? It is thought that there were no polar icecaps back then (world average T 12 deg C warmer than 1750, http://en.wikipedia.org/wiki/File:65_Myr_Climate_Change.png), so sea levels were about 80 m higher than present.

Space power? This is not a good energy investment.

http://physics.ucsd.edu/do-the-math/2012/03/space-based-solar-power/

That doesn't stop some people actually trying to do it. That's fine as a proof-of-concept, as long as analysts don't pretend the development is not profitable in energy terms.

http://www.solarenspace.com/

With genuinely unlimited stellar energy, we would cook the planet in short order.

http://physics.ucsd.edu/do-the-math/2012/04/economist-meets-physicist/

Yes, a small fraction of the CO2 in our atmosphere is the product of atmospheric methane which has oxidised in the air. That's quite apart from the much larger fraction which is the product of methane combustion (same chemical reaction, different physical circumstances).

Thanks for the links Jonathan.

Is energy from the Sun a good investment?

Considering that Mother Nature has been using stellar energy for 3.5 billion years to run the life engine and produce all fossil fuel that we have used to build our space age technology, there is one rather solid example of the Sun proving its worth.

Our challenge is to figure out how to make the Sun work for us.

The heat problem already exists, as the Sun is now 25 percent hotter than at the dawn of life and over the next 5 billion years will expand to the orbit of Earth as an aged red giant star.

The Earth will get pretty hot and sizzled well before then.

The Earth has been compensating for the hotter Sun and James Lovelock warns that our impact on Nature could drive the planet to a permanently hotter environment (p.108 'The Vanishing Face of Gaia').

James Hansen sees the prospect of a runaway greenhouse effect where the Earth dies (p.223, the Venus syndrome, 'The Storms of My Grandchildren').

The speed of the loss of the Arctic ice sheet should be a chilling bell of warning for us all.

We are in a state of emergency, where all tipping points could go, where giant algal blooms in dying oceans could release toxic hydrogen sulphide gas into the air that can kill life on land and destroy the ozone layer.

I read that this is what could have happened with the Great Dying 251 million years ago, but we are bringing it on very much faster and evolution could be entirely overwhelmed.

The main need now is to bring the carbon in the biosphere down to a safe level as swiftly as possible.

If we use space based solar power to extract the excess carbon at ground level, this will be a temporary measure to win back a safe Earth.

The carbon could also be extracted from the air in space and the clean air returned to the atmosphere.

With solar power stations in space, we can launch industry in space, which will reduce the energy demand on Earth.

In the long-term, all Earth's energy needs could be supplied with ground based solar power generation.

With a confident survival presence beyond Earth, we will be in a position to deal with the next monster rock that would kiss this planet.

The one that hit the Pacific Ocean 2.5 million years ago would today wipe out all coastal cities.

We need a plan for survival that will work, one which will mobilise the hope that will generate action.

We need action, or we may be closing the pages on human history.

Kim Peart
http://www.islandearth.com.au/

I am on Kim's side on this one.
The surface of a planet is not the correct place for industry.
And yes, we are going to have a date with the Infinite.

The illusion is to think that somehow, please dear God, somehow let us continue to live on the surface of this teeny tiny little ball of rock. We promise to be good. So You see Dear merciful Father we are being good, so you had better keep your side of the bargain, Bastard.

Grow up. Pack your gear. Time to leave home.

I was surprised to discover Jonathan,

that infinity is a natural part of the Universe and for us, many apparently finite aspects are as good as infinite.

We cannot see the edge of the cosmos and there may be no edge to the space-time continuum.

An infinite return on the investment includes from among the stars and galaxies, as with space, we know no limit.

Though we know the Sun must ultimately whimper away, it is so distant in time, it is like an infinity, for us.

It is impossible to imagine how much energy the Sun pumps out and will continue to pump out, all the way to becoming a red giant and beyond.

Our long-term plan on Earth needs to include a sustainable human presence, put if we struggle on Earth alone, I see the melting Arctic ice sheet and wonder if all tipping points will tumble.

We cannot design a future in the cosmos by the rules with which we have run this planet, because those rules have totally failed us.

We have totally failed to keep a safe planet, so the ways that have led us into failure are not the ways to secure our cosmic survival insurance policy.

I fear that we have a choice of continuing to follow the failed path on Earth, where our whole civilization is built on carbon energy, or we get real about making the transition to a stellar economy.

Rather than running through the maze that we have built on Earth like so many lab rats, if we expand our imagination to the Solar System as a whole and decide on what we must build and how we get there, then we can look at breaking out of the maze, building our celestial civilization and also be able to win back a safe Earth, where evolution can continue for a few billion years.

Evolution can also continue in our cities and islands in space, spreading across the Solar System and among the stars like so many seeds from Mother Earth.

We may not be fans of the Mongols, but they didn't achieve what they did by sitting around the campfires in Mongolia dreaming about it.

We may be stirred by the speech of Churchill and the determination of the British people to resist Hitler.

Would there have been a Moon landing if Kennedy had chosen to challenge the Soviets at chess?

There are times in human history when only by being bold, can we discover our destiny.

We were in a technical position to start building our future beyond Earth in the 1970s, when we could have kept a safe Earth by launching a stellar economy.

Now we must face the price of our failure to act on expansion when we could.

We would have achieved it all by now and be sending stellar explorers to the stars.

Will we wake up, before environmental catastrophes on Earth doom us to a terrestrial grave?

Kim Peart
http://www.islandearth.com.au/

Each of your brief paragraphs seems to contradict the next. Particularly, most of them contradict:

"We have totally failed to keep a safe planet, so the ways that have led us into failure are not the ways to secure our cosmic survival insurance policy."

Expansionism is precisely the way that has "led us into failure".

If we're fighting them on the beaches and on the landing grounds and in the fields and in the streets and on the hills ... the enemy is us.

Nevertheless...

I do agree that we should expand beyond the confines of Earth and the neighbourhood of our one fickle star.

Just not before tackling our urgent domestic problems inside the atmosphere.

My turning point Jonathan,

came in 1993, when I began asking "What does Nature want?"

This is not to say that Nature is conscious, but there is a powerful momentum in Nature and life.

One of the fundamentals of the cosmos is expansion toward increasing diversity, seen from the beginning of time.

Life has filled the Earth and if it could, would expand into the cosmos, so that we would see bizarre lifeforms floating around the Solar System, soaking in stellar energy and feasting on in-coming comets.

If Nature were seeking to expand beyond Earth, how could it happen?

What if a tool-making species emerged through evolution that could build spaceships and harness the planet's fossil fuel reserves?

The tool-mekers would be in a position to launch a stellar economy and make the transition from an Earth-trapped carbon economy to a space-liberated stellar civilization.

If this was an expression of Nature seeking expansion into the cosmos, what would happen if the tool-making species delayed the expansion and kept burning the fossil fuel reserves like there was no tomorrow?

We see what happens on Earth today, where we find a fast warming Arctic region and we may come to find that too many tripping points cannot be prevented from tripping and even all of them.

Astronomers believe that there should be thousands of tool-making species scattered among the stars, but we look out and discover a vast silence.

Like us, did ETs also fail to expand in time, burn their fossil fuel too long, even believe that they had to get their act together on their planet first, only to lose the lot?

We may find out one day, if we survive and find the husks of failed civilizations among the stars.

If the drive of Nature is for expansion, then to fail to run with Nature beyond earth is to block the flow of evolution and in effect, be fighting Nature.

With species of life being lost and ecosystems dying back, means that there are casualties in this fight.

We could have avoided this tragedy, by running with Nature when the time was ripe to do so in the 1970s.

We must now awaken to the primary law in the cosmos with expansion, if we wish to avoid becoming a casualty of our war with Nature

and if we wish to save the Earth.

Kim Peart
http://www.islandearth.com.au/

So in all the chaos of human development and political turmoil, you think we, as a species, missed the boat to go stellar in the 70s (incidentally precisely when US oil production began its decline), squandered the fossil fuel bonanza and brought about climate change -- in some sense morally as a consequence of abandoning the project of space colonisation.

The only problem with that argument is all the chaos of human development and political turmoil. Oh, and the fact that terrestrial insolation is 170 petawatts and already in 1912 we had the technology to exploit as much of that as we like, utterly dwarfing the maximum achievable fossil fuel extraction rates, if only we chose to do so. We haven't missed the off-world boat at all -- indeed we might be in danger of missing the renewables boat if we squandered fossil energy on space development.

Removing fossils from the energy equation must happen *before* any major expansion can take place.

I find it really cute and somewhat disturbing that again and again I find Tom Murphy has already done the sums to make my case in this argument :-)

http://physics.ucsd.edu/do-the-math/2011/10/why-not-space/

The business plan for launching a stellar civilization Jonathon,

was developed by Professor Gerard K. O'Neill and his associates at Princeton University in the early 1970s, is embodied in his 1977 book 'The High Frontier' and related research found at the Space Studies Institute that he founded.

NASA and the National Space Society also hold much information on this work and vision.

In my view, the killer question is, why didn't we act?

I am left wondering if this is yet another competitor killed off by the fossil fuel industries.

The strong Earth-focus that has predominated since 1970 has been to the advantage of the fossil fuel industry.

In terms of survival, if we found a killer rock heading for Earth and had ten years to act, I can see humanity working as one to rise to the challenge and build a solid presence in space to protect the Earth,

or at least assure our survival as a species.

Why wait for an Earth killer?

On the basis of the precautionary principle, why not act now to invest in our cosmic survival insurance policy, while we still can?

That is the whole point about insurance as a precautionary investment.

If the current environmental crisis leads to a global economic slide that blunts our space edge before we have invested in our cosmic survival insurance and we look up to see a killer rock heading to kiss the Earth, we will then see how completely we have lost the plot.

Waiting for the perfect hour to begin investing in cosmic survival may be no more than moving deck chairs around on the Titanic, as the deck begins to tilt.

With the Arctic region getting hotter, the ice dissolving, the oceans becoming acidic and the Great Barrier Reef shrinking, the decks of our spaceship Earth are beginning to tilt and we have no lifeboats.

If the basic cosmic survival need is embraced and acted on, then a spin-off benefit will be the generation of hope in the hearts of people, knowing that we will as a species survive, be in a confident position to win back a safe Earth, be able to design a stellar economy without poverty and look toward some rather amazing stellar exploration.

In lifting our game into space, we can identify the minimal platform that would be a sustainable presence beyond Earth, as we would then never be at risk of failing beyond earth.

Kim Peart
http://www.islandearth.com.au/

Like I said, I'm entirely in favour of expanding off-world. I'll even agree the sooner the better. But there's no energy surplus to fund it with from our present economic, energy and political situation, unless some dictator who shared your views were miraculously to take over most of the world economy without destroying it, then devote all our energies to it while retrenching bread, circuses and legions. It's clear that there's plenty of scope to retrench fossil fuels and avoid catastrophic climate change using terrestrial renewables and/or nuclear energy; insisting on doing it from space is a massive opportunity cost and a silly distraction from the desperate task close at hand.

The reason "we" didn't act is because spacefaring is spectacularly expensive, and the only nation ever capable of launching or funding such a project was hit by its own domestic Peak Oil moment in 1971 which was completely unanticipated by most people. Funds which might have been spent on stellar glory (or any number of other nation-building projects) were diverted to pointless wars, oil imports and domestic energy subsidies.

Now this guy, you will agree with me, is hopelessly pessimistic. But his viewpoint is absolutely correct in the absence of an economic evolution beyond the fossil fuel economy -- which must take place on earth *before* we can go back to space.

http://thearchdruidreport.blogspot.com.au/2011/08/elegy-for-age-of-space.html

I read the article Jonathan,

and found Greer's views a bit selective.

There was no mention of the role of Wernher von Braun and his amazing team that built the Saturn V ~ the most powerful rocket built to date ~ which delivered the Moon landing.

If Von Braun's vision had been followed, which came out of Germany, the space plane would have been on top of a rocket.

After the assassination of Kennedy, space budgets were slashed and the Moon landing was achieved, but the Saturn V was canned.

Would Bobby Kennedy have revived his brother's space vision?

We can never know, as he was also assassinated in 1968.

Where you mention "peak oil" in 1971, I wonder if you are thinking of the OAPEC oil embargo following the Yom Kippur War in 1973?

In the age of democracy, do we need a dictator to tell us what to think?

Consider my article ~ 'A Stellar Revolution' ~ just published by the Kepler Space Institute ~
http://www.keplerspaceuniversity.com/sites/default/files/SP-16-Peart-Final.pdf

Our future begins with individual choice and grows with support by others for that choice.

That is democracy at work ~ our choice.

If we want a national project for Australia that directs our resource bonanza toward building a real future in space, then it is our individual choice to speak to this and decide what in the hell we are going to do about it.

If we took the lead, we could build working partnerships with nations like India to build a space future for humanity.

The option was surrendered in the 1970s and all that oil wasted over 4 decades, that would have allowed us to make the transition to a stellar economy.

If we now see that our cosmic survival and the future of a safe Earth depends on real space development, the we can make an individual commitment to this future and promote this toward the numbers that will make it happen.

At the same time as we build a celestial future, we can look at all Earth needs and how we shift to a safe Earth where poverty is history.

All aspects of our lifestyle on Earth must be examined, if we want a safe Earth with coral reefs and koalas.

There may need to be radical changes, such as shifting long-haul transport to airships.

Winning back a safe Earth will require very careful planning on Earth, as we make our giant leap to a stellar future.

It is the hope generated by the giant leap that will inspire the gentle hand on Earth.

Talk of contraction offers no hope, as the reality of this is mass death, with no certainty that we will avoid a post-nuclear war stone age, or even survive.

Without dynamic hope, I fear that nuclear war will happen on an Earth going mad.

This madness will intensify, as we struggle to work all our problems out on Earth alone, where the walls are closing in.

A bombing of Iran could be the trigger.

I hope we act in time, to offer hope for all Earth's children.

Kim Peart
http://www.islandearth.com.au/

30% sounds really high ... I've read numbers like 0.1% leaked gas in some parts of the world, up to 10% in others. It varies depending on quality control and safety measures. Still, it's way too much. Total "Fugitive emissions" includes coal-seam methane and "associated gas" from oil fields that escapes without ever entering a pipeline -- and I suspect that with hydraulic fracturation that quantity has soared in the last decades.

I'll try to rustle up some numbers on leaks.

The current public reaction and government response to nuclear power in Japan and Germany cannot be taken lightly.

We have totally failed to keep a safe Earth, which the losing of the Arctic ice sheet testifies.

And now we wait for the methane to explode from the clathrates.

If nuclear was a perfect choice, why haven't we gone there already?

If renewables were a perfect choice, why not there already?

Unfortunately, the focus on Earth-only solutions to energy problems has been a boon to the carbon energy industries, with the really big option fading from sight.

The Sun is the biggest energy provider by far in the Solar System, which pumps out so much power and will do so for billions of years, even expanding to the orbit of the Earth as a red giant.

That is one hell of a power generator.

To win back a safe Earth and assure our cosmic survival, I suggest that we build solar power stations in space, launch industry beyond Earth and assure our future as a stellar civilization.

This needs to be our prime objective, or we run the risk of oblivion, by chasing the tail of the carbon dragon on Earth that is too large to vanquish.

We are not vanquishing the carbon dragon ~ no where near doing so ~ and the beast is getting larger fast ~ and if all 14 tipping points go, we run the risk, or the certainty, of a dead Earth.

Professor Will Steffen suggests that the tipping point for the Arctic ice sheet is now past ~ "I'm pretty certain that we have now passed the tipping point for Arctic sea ice.'' ..... "The only known way to stop these thresholds being crossed is to cut the human greenhouse emissions triggering these changes, and there are few signs of that taking place." ~
http://www.smh.com.au/environment/climate-change/tipping-into-new-climate-territory-as-scientists-put-fears-on-ice-20120922-26dq9.html

If our thinking can focus on the Solar System as a whole, we may be able to chart the plan for a safe Earth and our survival as a species.

With appreciation of the power of the Sun, we could generate solar on Earth to meet all terrestrial needs, especially if industry is in space and we shift to a slow Earth movement.

The development in Spain offers a sparkling option, storing energy in liquid salt at more than 500 degrees ~
http://www.smh.com.au/business/fund-studies-not-schemes-says-windsor-20110814-1it1r.html

How many of those could we build in Australia?

How many would we need?

Or energy storage could be with molten metal at over 700 degrees ~
http://www.newscientist.com/article/mg20627555.500-molten-metal-batteries-to-be-clean-energy-reservoirs.html

It is for the outer Solar System and in deep space that we will need fission or fusion power.

If we keep struggling with Earth-only solutions to our cosmic survival problem, we bury ourselves in too many good ideas that have not delivered, when we simply needed to reach to the Sun and get serious about our future as a stellar civilization.

We could have been acting on our stellar future in the 1970s.

We must break out of the thinking that has delivered total failure to keep a safe Earth and decide that it is finally time to succeed in the cosmic survival race.

Kim Peart
http://www.islandearth.com.au/

There's a bit of arithmetic to do there, since every percentage you quoted is a proportion of different things!

The Wuppertal one seems to be the most relevant. The link you pasted didn't work for me (permission denied) so I googled and found it here instead:

http://www.wupperinst.org/uploads/tx_wiprojekt/1203-report-en.pdf

and the most relevant thing I found there, to the question as to how much gas leaks, is

"... emissions from the export network -- not including the distribution networks inside Russia -- can be assumed to be approx. 1% of the produced Russian gas".

There are implications throughout the article that leaks are worse in Russia than elsewhere, though they don't blame this on poor management, just on the vast distances over which the gas is transmitted.

The 31% figure you quoted from p. 23 is of the total greenhouse emissions associated with *transmission* of gas ... ie. 31% of the global-warming-potential of the transmission system is from its methane leaks, the remainder being CO2 associated with the energy taken to move the gas (most of which is obtained by burning some of the gas itself, logically enough). It doesn't have much relation to the portion of the transmitted gas that leaks (which, since the 1% figure above includes leaks at production and scrubbing sites, must be somewhat lower than 1%).

This is exactly the kind of study I was looking for, actually, so thanks :-)

Hmm, yeah. Seems i jumped the gun there :) It's been some years since i looked at it, and I remember getting rather upset reading " Just under 31% of greenhouse emissions are due to the release of CH4" (methane), but rechecking I'm not sure how they got the number, relative what? The total amount of emissions from pipelines including CO2 from gas turbines etc? Where did you see the number 'one percent' being the loss through venting etc?

As for leaks being worse inside Russia I expect that to be true. Saw 'unreported' leaks that lighted a nearby town (with photos) in the middle of the night, making it rain in the winter. But my info is at least two years old, and the tundra which they and the Canadians too build pipelines on are weakening constantly due to the warming near the arctic, creating morasses.

I would dearly like to see if it 'only' is one percent though, so if you have some relevant links to that statement I'm interested.

Thought I had stopped this :) Got really tired reading about the common stupidity of mankind.

But you got me interested again. If Australia allow underwater mining and supertankers digging for frozen methane? As well as Russia is planning several new fields and pipelines, some (most) of them under water. Which the Nordic Countries in their impenetrable wisdom have given a green light for?

Don't really think we need to worry about any methane 'tipping point' not being visible (as far as I know) geologically/historically. We will do just as fine without it. And the real trump should be placing those pipelines under water :)

And with Gazprom being owned by the mob, more or less :)
And the rest (western) being 'ethical' green, although ever so private enterprises for profit.

Brainacs are us.

In Why Not Space? some of Murphy's arguments are silly straw men. And his math is wrong. Those who cite this article demonstrate they haven't actually done the math. http://hopsblog-hop.blogspot.com/2012/02/in-his-blog-stranded-resources-tom.html

Thanks for that David. Valid, constructive criticisms, all of them.

I don't know that any of those void the basic point that space-based solar power is hugely more expensive than obtaining the same energy from the same source here on the surface of the Earth, or that we don't have the option to defer addressing climate change until after we establish a "sustainable" presence off-world.

Let's establish a sustainable presence here, first.

When you write Jonathan,

"Let's establish a sustainable presence here, first."

is it OK to wonder why this hasn't happened already?

Considering the rapid rate of deterioration in conditions on Earth, what are the chances of this ideal ever being achieved?

That way does not offer hope or vision for a better world.

Establishing a sustainable presence beyond Earth will place our species in a better survival position and this simple act will generate hope on Earth.

By driving a vision that includes cosmic survival and a healthy Earth ~ including a future that is free of poverty ~ we can hope to inspire many willing hearts and keen hands to also participate in winning back a safe Earth.

With a survival presence beyond Earth, we will have access to stellar energy to pursue any industrial process, at any temperature.

Our survival presence beyond Earth can be expanded as needed, or desired, with no impact on Earth.

Our star is an extremely powerful cauldron of energy and in space we have access to its power in any location.

Why gamble with survival by struggling with failed ideas of a sustainable presence on home planet?

Our stellar future ~ with a safe Earth ~ can happen when enough people decide that it must happen and demand action.

Our future is in our hands and with the way the environmental cards are falling, along with our survival.

Kim Peart
http://www.islandearth.com.au/

Our presence on Earth WAS sustainable, until we harnessed fossil fuels.

If our sustainable presence on the home planet is a failed idea, we ourselves are a failed idea.

I think more highly of us than that.

Currently Jonathan,

our civilization has failed to keep a safe Earth, let alone a sustainable presence on this planet.

With the tipping points tumbling like gamblers cards in the Arctic, we must now face the prospect that our survival is at risk.

Human evolution has been on a trajectory that led to the Moon landing, but then we lost the plot.

The "failed idea" is that we have to work everything out on Earth alone.

Following Apollo, we should have been working everything out in the context of the Solar System as a whole.

By getting back into the trajectory of evolution, we can win back the plot, assure our survival, design a stellar economy without poverty and pick up the pieces of our failure on Earth.

The alternate rests in the detail of the Arctic methane clathrates waiting to explode into the atmosphere and send the planet off into a runaway greenhouse.

Kim Peart
http://www.islandearth.com.au/

"We" didn't "lose the plot", America hit an economic ceiling.

Working things out on Earth isn't a failed idea. As you said at the start, Nature has been working things out quite nicely on this planet for a few billion years now.

The money that goes to space exploration is a minute fraction of the budget. And we haven't hit peak oil yet, much less where we approaching it in the Apollo days.

The money that goes to space exploration *now* is a minute fraction of the budgets of the nations that still pursue it. The money to make a permanent "sustainable" human presence off-planet would not be -- it would be freaking enormous.

I didn't say "we" (the globe) have hit peak oil. I said the USA hit an economic ceiling, triggered by its own domestic oil production peak in 1971. This is a matter of record. It perhaps isn't as directly connected to the decline of the space program as I implied (the ideologically-driven Vietnam War probably had much more to do with it, as Kim said), but it did permanently curb US expansionism.

Peak oil is a complex economic phenomenon. The effects of peak domestic production on individual nations vary considerably. In the case of both the USA and the USSR, the domestic peak caused major changes in their imperial capacities and policies. Now it's clear in hindsight that the USSR's peak was not a peak for that geographical area; it's also clear that high prices in the last few years have enabled production in the USA to grow again through the use of more expensive production techniques, even as they have pricked investment bubbles and caused mass unemployment in other economic sectors.

Global oil production has indeed not peaked, but for several years recently (2004-2009) production did not materially increase despite soaring prices, which indicates that inexpensive "conventional" oil (ie. large fields which can be tapped with relatively few wells) was unable to increase supply despite increased investment. Indeed gross global "conventional" oil production has begun to fall, though the super-giant fields of the Middle East are yet to enter their own terminal decline which will be the clincher. Only far more expensive techniques including tar sand mining and hydraulic fracturation of shale rock ("tight" oil), requiring an order of magnitude more investment to yield the same quantity of oil, have extended supply in the last three years. Though production may continue to increase for some time yet, we are in some sense already scraping the bottom of the barrel. When the giant conventional fields of the Middle East and Russia finally hit their inevitable production ceilings, we will be in for a *very* bumpy economic ride.

The 2008 event was a clear indication of demand outstripping supply (probably triggered by speculation on the futures market, just as the Saudis said) and the consequent high prices causing recession and significant demand destruction in the countries most vulnerable to oil price spikes such as the USA itself, Greece and Tunisia.

The oil price since 2009 has essentially been determined by the level at which it would cause American consumers to stop buying it. That's a complete reversal from the pre-1970s situation during which Texan regulators tried to keep levels of investment steady.

Nobody can call global peak oil in advance (despite many eager geologists and economists' attempts to do so) because demand for oil has proven itself to be much more price-elastic than previously assumed. This means that many people and countries are now able to improve efficiency, or conserve consumption, or adapt to other energy sources, more readily than previously assumed. The less we depend on oil, the more we can afford to pay for it. Possibly the global oil production peak will only come once other energy sources are able to out-compete ever-more-expensive oil.

If entities like Planetary Resources can profitably mine asteroids, an increased human presence and growing space infrastructure would follow as a matter of course.

Given propellant sources other than at the bottom of earth's gravity well, space transportation becomes much less difficult and expensive.

Given these same propellant sources, life support consumables are available onsite, no need to haul them from the bottom of earth's gravity well.

Given Moore's Law and advances in telerobotics, we will be able to an increasing amount of work in high radiation, vacuum environments from the safety of a hab.

There are a number of routes to an affordable (even profitable) human presence in space.

The problem with talking about "profits" is that all the money is down here.

The only possible profit to Space Resources in the short term is in finding minerals on an asteroid that are scarce and highly prized on the surface of the Earth (nickel? Is there really that much demand for it?) and bring them down. They won't be going to asteroids specifically for propellants and the like (water ice?) -- that would be a component of a seriously long-term project involving space-based processing. Gravy if they can get both in the same place, of course, I don't know if that's likely.

Earth has all the markets, all the labour, all the breathable air, all readily-available clean water, all the processing industries, etc. You *could* put each of those things in orbit, but unless you can find a way to make every stage of the process (not just importing minerals) profitable *on Earth*, it's an incredible investment.

Granted, nanorobotics and the like will bring incremental costs down as terrestrial launch payloads shrink. But that's not really related to "having lost our way in the 1970s" nor to addressing climate change (!) It's about having another go, later, using technology we've profitably developed here on earth for other purposes. Perhaps even without using fossil fuels :-)

"The problem with talking about "profits" is that all the money is down here."

Wrong. There are many billions of orbital assets in cislunar space. Communication sats. Weather. GPS. Surveillance. Easier access to these extremely valuable assets would be an immediate economic benefit.

The first resource Planetary Resources hopes to bring back is water. Propellant high on the slopes of earth's gravity well would break the exponent in Tsiolkovsky's rocket equation and make space transportation much more economical.

Given more economic space transportation, it becomes easier to maintain and upgrade our orbital assets. It also becomes easier to reach near earth asteroids, some of which are rich in platinum group metals.

Here is Planetary Resources page on water usage: http://www.planetaryresources.com/asteroids/usage/

Nickel? Nanobots?! Where have I written about nanobots? Please don't waste my time asking me defend positions I haven't made.

As you say Yoron,

we cannot hope to expand into space with "a depleted Earth."

I fear that if we do not act now on our survival presence beyond Earth, we will be left on Earth with our survival at risk and the real prospect of the Earth falling to a runaway greenhouse, as a direct consequence of changes already in place.

Though it may seem that we will behave badly in space, I suggest that a new dynamic will come into play beyond Earth, because of the security needs in space.

To assure security in space, we will need to work toward a more peaceful Earth.

This is a feed-back loop that can be explored and if we are determined to open the celestial realm for human activity, then we can promote this future on Earth now.

I explore this in ~ 'Creating A Solar Civilization' ~ on our website.

In 1986 Robert L. Forward proposed sending small stellar explorers to the stars, accelerated to a high velocity using a laser beam powered by the Sun driving a solar sail.

Such explorers could be filled with nanomachines and as you suggest, this is one way we could launch development beyond Earth, where remote control systems could be used from Earth, along with robots, to build safe environments for human habitation.

Kim Peart
http://www.islandearth.com.au/