I posted this on Slashdot today

Earth is not a sustainable system. The Sun is getting brighter; in less than a billion years it will be too intense for Earth's oceans to continue to exist. Like Mars did in ages past, Earth is going to lose its water. On the other side of the balance, Earth's interior is cooling, geological activity is diminishing, and so volcanic replenishment of the atmosphere is slowly winding down. *These* are the long term environmental trends; at such time scales it is clear that no amount of "recycling for a better world" will make a difference.

It is also clear, at such time scales, that the entirety of life on Earth will go extinct if life does not branch out off the planet. That means launching equipment and people to build massive, robust infrastructure. Crops. Botanical gardens. Zoos.

Except that space is HARD. It's really expensive to get there and it is a high-vacuum radiation hell. It would take a long time and an expensive, sustained effort to construct off-planet habitats - a *tremendous* amount of effort and money before there is any payoff at all.

On the other hand, for example the asteroid 16 Psyche contains enough metal to construct a solid cylinder three miles in diameter stretching from here to the Moon. Or cover North America in a layer 900 feet thick. The resources available to an outer space civilization are great enough to insure that if outer space habitats do reach the point where they can expand and grow, the payoff would be big enough to sustain life past the death of the Sun.

We are half-way through the era of animals on Earth. There have been at least a half dozen mass extinctions since animals first started evolving a half-billion years ago; there will be more. The glaciers have grown and retreated dozens of times over the last two million years; they will return. Yellowstone is going to explode again. And again. And again. Time is not unlimited.

But we have time. Abundant fossil fuels, and the internet - we are right now living in the decades of maximum wealth. At some point, within a few decades, we will either run out of fuel or we will run out of the capacity to sink carbon emissions. When this happens, it will mean the end of a way of life. Maximum wealth *right now* means that *right now* is the best and possibly the only time to lift off. Life on Earth only gets one pass at the fossil fuel heritage; if the next extinction event brings us to a place where launching is not possible, life will have missed its chance.

I am a realist. I'm certain that outer space settlements will not solve our current growth vs. environment problems - the payoff will come way too late for that. None of our current issues will be solved, or even mitigated, by vigorous and immediate launches into the great expanse. Nonetheless, if DNA is to avoid extinction we need to start moving now as rapidly as we can. Nothing else matters.

The cocoon we call Earth is going to wither; whether or not she gives birth before she dies is entirely in the hands of human civilization. Our civilization, right now, we're the only chance. Sure, leaving Eden is a horrible burden. Suck it up. We have to go. Now.

Or, we can continue toasting marshmallows at the planet's one-time-only oil burning party.

Sustainability

Earth is not a sustainable system.

The Sun is getting brighter; in less than a billion years it will be too intense for Earth's oceans to continue to exist. Like Mars did in ages past, Earth is going to lose it's water.

On the other side of the balance, Earth's interior is cooling, geological activity is diminishing, and so volcanic replenishment of the atmosphere is slowly winding down.

We have less than a billion years. We are half-way through the era of animals on Earth.

Anthropogenic Global Warming exists. It's a tragedy, but it's only a blip in the larger span of the ages. Humans are going to set fire to all the fossil fuels we can possibly get our hands on and we'll do so as fast as we possibly can. Nothing anyone says or believes will change this fact.

We only get one pass at this fossil fuel heritage.

Which means we are right now living in the decades of maximum wealth. If life is to continue, life must branch out off the planet. If this is going to happen, we have to be the ones to do it, and we have to do it now.

Earth is not sustainable. We have to go right now.

Save The Planet

The Earth as we know it, over the entire history of our species, is but an extremely short snapshot in time. Human culture is even younger; the oldest of writing, the most ancient of oral traditions, all of what we are, it all amounts to – a blink. A marvelously stable run of years, with a stable climate and a stable supply of the necessities of life: Land, Air, Water, Energy, other life forms, it's all here, in abundance, in this system we call “The Planet”. This system, this blink in time.

What does it mean, “Save the Planet”? What is “Sustainability?” Does sustainability mean: help The Planet continue to exist in a condition similar to the condition it has been in for the last 10,000 years? Is the goal to make the blink last as long as possible? 100 years? One would hope that's doable. Preserve and conserve for 1000 years? That might even be possible. What about another 10,000 years? Things start to look less certain. Extend that to 1 billion years, and Earth becomes a dry ball orbiting a sun grown much hotter than the one it orbits today.

Save the Planet? The Earth is an evolving system that has always evolved and will continue to evolve. It has gone through at least a half dozen mass extinctions over the last half-billion years. There are more to follow. The glaciers have grown and retreated dozens of times over the last two million years. They will return. The Planet is not stable. The Planet is on a wild ride.

Does the destructive nature of the accelerating Human presence mean that Humans are currently the cause of the next, currently occurring mass extinction? Possibly. But what can can be done, really? Reduce the footprint of each individual, there are going to be many more individuals in a very short amount of time. Further, even if some miraculous way is found to end environmental destruction everywhere . . . there will still be more ice ages, and more mass extinctions to follow. This much is out of our hands, the wild ride continues. In which case, if the miracle environmental cure is found, what really have we saved? Our conscience, maybe, but we're certainly not saving the Planet - we're just passing the buck.

The hard fact is, the Planet is not sustainable. With or without Human intervention, with or without Human indifference, with or without Human intention, the Planet is not sustainable. Like Death and Taxes, there is nothing we can do about it. The blink will end.

Some thoughts on the scales of time and space

Who paid for World War II?

Plastics are entering the geological record. In a few hundred million years, some future geologists will probably be able to read the fossil remains of the odd cd or two, incorporated into the rock.

Most petroleum reserves started 300 - 400 million years ago, when our ancestors were just gaining the ability to lay their eggs on land instead of in the water. The oldest reserves, however, date back to a time when our ancestors, tiny little ocean creatures, were diverging from the ancestors of the insects.

It is probably the case that some of the petroleum and natural gas we burn today consists, in part, of the direct remains of our ancestors.

Cheap oil, and the internet: these are the decades of maximum wealth.

The earth is in between ice ages. The next one will be in a few tens of thousands of years. In the midst of the last one, we won the great Cro Magnon/Neanderthal smackdown.

The sun will steadily increase in brightness over the next few billion years. A billion years from now, the oceans will have evaporated away and the whole planet will become a desert, completely sterilized of life. Life has existed on earth for 3.5 billion years, and it has no more than 1 billion more years to go.