A lot has been said on the topic. A significant portion of what has been said is subject to interpretation.
First of all I’ll probably upset some people by saying that yes the globe is warming. And I will further upset some of those people by pointing out that humans have had something to do with that situation.
Gerry Pournel pointed out on TWiT a week ago or so that if you went to school in the United States in the past 50 years, that you very likely were taught in grade school just about everything you need to know to confirm the first of those assertions. What you may not have been taught, you can easily look up.
During the Revolutionary War, General George Washington very nearly lost the war on the shores of the Potomac river. What saved him was a contingent of cannons that were delivered across that river. Cannon. They were not delivered by boat, they were horse (or oxen) drawn on their road carriage across a river frozen over with enough ice to support them.
“So what,” you say, “rivers freeze every year.” Well the bit you get to look up is when the Potomac last froze solid enough for a man to walk across where those cannon were carried over it. As a hint, it’s been over 100 years since it last happened.
Yeah, well, OK, the world has been warming. Turns out it’s been warming something like a degree a century over at least the past 2 centuries. So what you ask. These things go in cycles. Yes they do. There are a variety of cycles involved.
Lets look at at least one of those cycles. The sun has a reasonably predictable 11 or 22 year cycle. From a ‘counting’ perspective we use an 22 year cycle and the cycle that we should be seeing sunspots increasing now is the 24th cycle since we started counting sunspots at all. That means about 500 years of data, give or take a bit, and of course up until we started using some fairly modern techniques, we very easily could have missed about half of the sunspots, as they can be of short duration and only appear on the far side of the sun. However we can use the data that has been gathered to look at other environmental records and perhaps learn something more.
Within the past 400 years or so we have things like the little ice age, the Maunder Minimum, the United States’ Revolutionary War, and more. So we know that there have been fairly major climate events in that time, and we can corelate that perhaps to sunspot numbers. It turns out that there is some correlation. During the Maunder Minimum, a 50 or so year period when there were very few sun spots, we saw what has been called the little ice age. Art from the period shows people having carnivals on the Thames river, and more. Now there are a lot of people who will point out that correlation does not mean causation. They are right. There are several other events that may have had a global impact in the years of the Maunder Minimum.
One of the things that we can show however is that years with a lot of sunspots tend to encourage trees to grow thicker rings. And years with fewer sunspots tend to have thinner rings. Again correlation does not suggest causation, however we consider that, along with snow fall records in ice cores, and the sedimentary record in the existing seabed as showing enough correlation that we can use them to give us a picture of what we believe the solar cycles have looked like going back about 11,000 years, or to the end of the last major ice age.
Obviously there are other cycles at work over a period of 11,000 years. For example the north pole precesses in a 26,000 year cycle. What we call Polaris or the North Star was tens of degrees away from the stellar pole at the end of the last ice age. Additionally looking at the orbit of the earth it varies a bit as well. However the periods involved do not match up as clearly as people who are pointing at them would like. Likewise pointing at the history of Hurricanes in the US has issues, as there are only about 300 years of any history, and less than 200 years of good records. Up until about 100 years ago a hurricane that hits Florida, then Mississippi may have been counted as two separate storms.
So far the strongest evidence of a correlation between something and the climate has turned out to be volcanic dust and CO2, and the global temperature. The pattern is very much an appearance of significant volumes of dust in ice cores, followed by a spike in CO2 of nearly 100 ppm, followed almost immediately by a jump of 10 degrees C. For those of us in the US, that amounts to a change of 18 degrees or so.
100 parts per million translates to a change of .1% keep that in mind.
Looking at the history of global ice ages we see that the tempreture, dust, and CO2 changes, appear in roughly a 80-100 thousand year cycle. That’s between 5 and 10 times the amount of time since the end of the last ice age. So we should have a good ways to go before the next major ice age sets in. Right? Not so fast.
Looking at the history, we see that after each of these spikes we see a drop of 4-5 degrees over the next 10-20 thousand years. There is also frequently a drop of 8 degrees followed by a rise of 4 degrees or so over the 30 thousand years following a temperature spike. In any case once the temp has settled to about 5 degrees below the spike it begins a gradual decrease over the next 40 thousand years or so.
There are a couple of variations to that pattern. The temperature spike previous to the one that just passed about 10-20 thousand years ago shows a longer period of significant dust in the air before CO2 and temperatures spiked. There was significant amounts of dust in the samples for about 40 thousand years rather than the 5-10 thousand years that previous cycles show. Additionally the temperature drop off after the spike was a bit slower. At about the end of the last ice age we see a return to a 5-10 thousand year period of increased dust, but the volume of dust is almost half again the volume of earlier cycles.
“So,” you may be noting, “it looks like we can attribute super volcanoes to the end of ice ages, Eh?” Well, perhaps. Here’s the thing. The last major super volcano eruption we can date at this time is the eruption of Toba between 70 and 75 thousand years ago. The amount of dust in the samples after that event and the apparent duration of those samples, pale in comparison to the amount of dust in the air at the end of the last Ice age. Toba actually happened in the middle of the last ice age. Starting about 20,000 years ago the amount of dust in the samples rose from about .2 parts per million which is what things settled down to after Toba, to over 1.2 parts per million over 25-30 thousand years, then hung out there for between 8 and 12 thousand years. After that it dropped to what appears to be less than .1 part per million today.
If we limit the view of what causes global ice ages to end to being an increase and drop off in the amount of dust in the air, then about now we should be between 2 and 4 degrees lower in temperature than at the end of the last major Ice age.
We are not. In fact we are about half a degree Celsius below the peak. And depending upon who’s data you look at, or more accurately where it was sampled from, the temperature has risen over that period by as much as a degree.
The other interesting characteristic of what we see since the end of the last ice age is that global CO2 count has not dropped off. In fact it has increased. Looking at the chart for the past 4 major ice ages, the CO2 volume went from about 260 ppmv 10-15 thousand years ago to between 280 and 300 ppmv today.
Now before someone suggests that I am going to tie a cause to this, and say that we are at fault, I’ll say I don’t know that we are, or are not. We’ve enjoyed 10,000 years of very warm weather, and human civilization has flourished over that time as well. We’ve gone from fairly small communities in the golden triangle and what appears to be disparate communities in what is now Egypt to what is almost a global civilization.
So why do I think we’ve had an impact on CO2 counts? Well other than the obvious growth of our population and civilization which needs more energy every year, we can look at three sets of numbers that show our impact on resources as well. First up is wood and grasses. Our burning of these has reduced per person over the past 500 years. Most of us do not use wood burning stoves as our means of cooking or heating except when we do things like going camping or otherwise ‘living off the land.’ For centuries one of the most effective means of herding and hunting was to set fire to wide swatches of grassland. However over the past 200 years we have changed our herd management procedures significantly. Some discrepancies to this statement can be seen in the way forest fires have been handled in the continental US, and the fact that large swaths of amazon forest have been destroyed by burning for farming. Additionally these all have some impact on CO2 levels as a result of the fact that not only do the fires release significant quantities of CO2, but they also reduce the ability of those resources to capture CO2 and convert it into O2 for breathing and Carbon within those plants.
Next up is Coal. Prior to large scale smelting of iron into steel, coal was widely used as an alternative to wood for heating and cooking. However the largest use of coal today is for the production of electricity. In that capacity as well as in high temperature manufacturing other than Aluminum, we are using more coal every year to the tune of 3.5 billion tones of coal in 2008. While there are swamps and marshes that are developing what will very likely be coal millions of years from now, there are not a lot of people suggesting that this process is keeping up with the volume of coal that we are burning. Additionally we may have a 50-200 year reserve of coal that appears to be recoverable. According to BP we used more energy as the result of burning coal in 2008 than we did in the combined oil and natural gas usage. This is significant in that it shows a change over previous years. Our current growth rate for coal consumption is between 2 and 3%
Oil and Natural Gas are our other major contributors to CO2 in the atmosphere. As can be seen by the BP report, the consumption of Natural Gas and Crude Oil is about the same as for Coal consumption. Something to consider though is that a significant percentage of that consumption is not burning. Other uses of Crude Oil that count as consumption, but which do not release significant volumes of CO2 to the atmosphere include the production of plastics, and things like the use of the heavier distillates for road and roofing surfaces.
So yes we are seeing global warming, and I happen to think we are contributing to it. “Ah ha!” you declare. “You’re one of those ‘carbon credit’ fans.” Actually I’m not.
What are the likely scenarios for the next say 200 years. Well, it looks like we are going to run out of crude oil and coal. At least the easily recoverable resources will be depleted. For almost a century Japan was mining coal from the sea floor, and we may find that there are significant resources for that that can extend the deadline, but I’m not going to suggest that it’s a reasonable method of extending our energy needs. I suspect that in 200 years burning coal will be pretty much limited to artistic usage. Showing how we once made these things. If you look at how we once fired ceramics, and compare it to our methods these days I suspect that you will see some of what I mean.
Over the next couple hundred years I suspect that we will see two significant sources of energy developed. The first will be a resurgence of nuclear power plants. Whether that will include Fusion power or not I don’t know, but the interim stop gap will be an increase in the wind and solar power gathering, and very probably some novelty wave and thermal incline power generation. There really is enough power in wind, solar and water to support our needs for the next century, however everyone will point out that where that power is most available, and where the demands for it are, don’t tend to be the same locations. So I suspect we will use Nuclear power in addition.
Beyond that we are pretty much going to have to move to space for additional energy. This will be in a couple of different processes. Initially we will see power collection and transmission to earth. The advantage of working with solar power in space is that you never have to deal with a cloudy day. Hail is never going to be an issue. You never have to go and clean the snow off the solar panel to let the sun in. You are not spending 12 hours on average out of 24 with your solar collector sitting in darkness. It almost sounds wonderful, doesn’t it.
What is the problem? Well, how are you going to get the energy from where you collect it to where you need it?
What are the problems? First of all it’s not like you are likely to be sending up a power cord from New York up to a geostationary orbit 23k miles up. That’s a lot of copper to begin with, and New York isn’t exactly positioned well for something in geostationary orbit. Your bes pet there would be a equatorial receiver of some sort that then redistributes the power to where it is needed. Can we say ‘land grab’? The second problem is that geostationary orbit is not a great place to put power collection. At the moment there are something like a thousand satellites sitting in that orbit. Some ‘parked’ others actively being used for television and other communications. Now a significant percentage of that usage is going to be eliminated and replaced with the global fiber optic grid, but we will still be using the majority of those, and other than providing a ‘stable’ point to potentially host a space elevator that may be used for power carrying as well,. I’m actually thinking not but that’s simply because I don’t see the materials that are expected to be used for space elevator as a good means of also carrying power. So we will very probably see a combination of space elevators near otherwise populated equatorial locations, and power conduits at a few other locations. We are back to our problem of distributing the power. Equatorial sounds wonderful, but we already know that transmitting power over long distances introduces a significant amount of loss.
Beamed power sounds like it might be an effective alternative. If you use a Maser to beam power you can focus it to provide a significant amount of it to specific spots. This can be used to provide an alternative to running electrical conductors out to space, and hopefully would help with the problem of serving some place like New York or Moscow, but I do think you will very quickly run out of space in GeoSync orbit, which introduces a new problem.
There are a collection of places in space around the earth relative to the moon, called ‘Lagrange’ points. These are points where the gravitational influences of earth and the moon are such that you can put something into one of those spots and it will remain reasonably close to where you left it relative to the moon and earth. Not all of these spots are ‘perfect’ in that some of these spots are a bit like balancing a ball on a fingertip. Yes you can do it, but gravity is working to move what you put there off of that spot. Some of the spots are ‘stable’ though in that they act a bit more like a bowl. it takes energy to get things that you put into these spots out of them again.
If we just deal with the earth/moon platform we have two things to take into consideration. I’ll leave out the Lagrange point on the far side of the moon, as I don’t think it seems like a great place to be collecting power for the earth. There’s this rather large object in the way of getting the power back. So we have two issues. The period of the orbit for these spots. Call it 29 days (and a bit more.) The other issue is the speed of rotation of the earth itself. At the equator (which currently isn’t a very high demand area for power, the surface is moving about 1,000 miles per hour. As you move away from the equator to higher latitudes, you can use trigonometry to calculate what the surface speed is at each of those locations. The important part to remember though is that from an L# spot, any given power destination is a moving target. Well, except for two of them. The North and South poles may very well be good down link sites for space gathered solar power. But then again, neither is exactly positioned well for power distribution.
So the question becomes how much power do we need to beam to these locations? Well, if we continue to use the power in the same way we do today, then let’s presume that the demand is equivalent to the amount of energy that we derive from coal and oil combined. Or do we need to do that? If we are collecting power in space, that means we have the means to do work in space. Why smelt steel on earth when you can do the same in space? Well steel is probably a bad example. but you get the idea. There really are far more resources to work with already in space than we are likely to ever make use of. Everything from asteroids that are as old as the earth, to satellites that have outlived their usefulness and are potential navigational hazards. Except where things work better in a gravity field, there is a lot of potential for manufacturing and refining in space. (by the way, distillation does work better in a gravity field, which doesn’t change the fact that it will be done in a zero or reduced gravity environment as well.
Long term, what is the fly in this ointment? War.
While much of Opec will see a decline as a result of oil field depletion, many are in a great position for gathering solar power. Of course there’s that distribution issue, but I don’t think that’s where they are going to see the biggest problem. The actual issue is that they have to convert from one energy resource to another. And that variety of conversion has never been easy. As a population we tend to avoid major changes if possible. There are people who will never read this post, not because they are not computer literate, or can’t find it, or even have no interest in the topic. There are people who will never read it simply because it is on a computer some place and these people view computers as tools to do calculations, and any other use is silly. I know people who look at Windows as a way to get to DOS where they can do the things they want to do on a computer. Note that these people were the early adopters of their time in that they made use of new tools to do something that would have taken years to do with previous methods but now take seconds of minutes.
At some level there will have to be a global regulating government. Not because people are rebellious, but simply because we will need to have common understanding in how things function together. We’ve already ‘fixed’ some of our infrastructure issues. There are still two primary power systems in use, 110 v 60 hz, and 220v 50 hz. There are some variations on this but those are the two primary solutions. If I buy a computer today in the United States, will I have an issue using it in Germany? Probably not. The switching power supply in use on the computer may need a different AC plug to attach to the local power, but that will cost me less than $10 or the Euro equivalent once I get there. I will probably be able to borrow one from the front desk of the hotel, or get one from my companies on site tech support person. The same is true pretty much anywhere you go on earth. And that tends to apply to other technologies as well.
How is this possible? The International Standards Organization has documented standards for each location, and manufacturers build their equipment to work with those standards. There are exceptions of course, but there always will be. An example from the world of mortars is the 81 mm mortar. It doesn’t exist because it is technologically better than an 80 mm mortar, or can deliver a larger explosion, etc. It exists because the opposing army was using 80 mm mortars. Using an 81mm mortar meant that if we over ran the opposing forces mortar supply lines, we could use the 80 mm mortar shells. If they somehow came into possession of our 81 mm shells, they are pretty much useless to them, as they won’t fit in the mortar tube. This is an example of building a technical platform so that your opponent can’t take advantage of you the way you can take advantage of them. Those same techniques are being used around the world in many fields.
How does this lead to war? We are going to continue to treat resources as scarce, and as a result we will end up attempting to force other people to make those resources available to us, and they will continue to try to make our resources available to them. We’ve been pretty much fighting one war or another for over 10,000 years. I don’t think anything we do now with the peace process is going to change that.
