In my previous two posts I have discussed how we could assist climate change by reflecting light back to space, and some ways to take carbon dioxide from the atmosphere. However, there is another important option: stop burning fossil fuels, and to do that either we need replacement sources of energy, or we need to stop using energy. In practice, reducing energy usage and replacing the rest would seem optimal. We already have some options, such as solar power and wind power. New Zealand currently gets about 80% of its electricity from natural sources, the two main ones being hydro and geothermal, with wind power coming a more distant third. However, that won’t work for many countries. Nuclear power is one option, and would be a much better one if we could develop a thorium cycle, because thorium reactors do not go critical, you cannot make bombs from the wastes, and the nuclear waste is a lot safer to handle as the bulk of the radioactive wastes have very short half-lives. Thermonuclear power would be a simple answer, but there is a standard joke about that, which I might as well include:
A Princeton plasma physicist is at the beach when he discovers an ancient looking oil lantern sticking out of the sand. He rubs the sand off with a towel and a genie pops out. The genie offers to grant him one wish. The physicist retrieves a map of the world from his car, circles the Middle East and tells the genie, ‘I wish you to bring peace in this region’.
After 10 long minutes of deliberation, the genie replies, ‘Gee, there are lots of problems there with Lebanon, Iraq, Israel, and all those other places. This is awfully embarrassing. I’ve never had to do this before, but I’m just going to have to ask you for another wish. This one is just too much for me’.
Taken aback, the physicist thinks a bit and asks, ‘I wish that the Princeton tokamak would achieve scientific fusion energy break-even.’
After another deliberation the genie asks, ‘Could I see that map again?’
So, although there is a lot of work to be done, the generation of electricity is manageable so let’s move on to transport. Electricity is great for trains and for vehicles that can draw power from a mains source, and for short-distance travel, but there is a severe problem for vehicles that store their electricity and have to do a lot of work between charging. Essentially, the current batteries or fuel cells are too heavy and voluminous for the amount of charge. There may be improvements, but most of the contenders have problems of either price or performance, or both. In my novel, Red Gold, set during a future colonization of Mars, I used thermonuclear power as the primary source of electricity, and for transport I used an aluminium chlorine fuel cell. That does not exist as yet, but I chose it because for power density aluminium is probably optimal for unit weight, and chlorine the optimal for the oxidizing agent because chlorine would be a liquid on Mars, and further under my refining scheme, there would be an excess of it. Chlorine has the added advantage that it reacts well with aluminium and the aluminium chloride will contribute to the electrolyte. As it happens, since then someone has demonstrated an Al/Cl battery that works very well, so it might even be plausible, but not on Earth. One basic problem with such batteries is an odd one: the ions that have to move in the electrolyte usually interact strongly with any oxygen atoms in the electrolyte, thus slowing down, and reducing the possible power output. That is another reason why I chose a chloride mechanism; it might be fiction but I try and make the speculative science behind it at least based on some correct physics and chemistry.
So, in the absence of very heavy duty batteries, liquid fuels are very desirable. As it happens, I have worked in the area of biofuels (and summarised my basic thoughts in an ebook Biofuels) and with a little basic arithmetic we find that to replace our current usage of oil, and assuming the most optimal technology, we would need to add another amount of productive land equal to our total arable farmland, and that is simply not going to happen. That does not mean that biofuels cannot contribute, but it does mean we need to reduce the load.
There is more than one way to do that. In one of my novels I came up with the answer of having everyone live closer to work. Where I live, during the rush hours there are streams of cars going in opposite directions. If they all lived closer to work, this would be unnecessary. Everyone says, use public transport, except that if you do, you see the trains are choked at that time of day. Such an option would require a lot of social engineering because the bosses want work done at centres where they think it should be done, while the workers cannot afford to live anywhere even vaguely nearby. That means social engineering is required, and people tend to object to that, and politicians will not impose it on the bosses.
As mentioned in my last post, a slightly better option is to grow algae. Some of these are the fastest growing plants on the planet, and of course as far as area is concerned, the oceans are unlimited, at least at present. Accordingly, it should be possible in theory to solve this energy problem. The problem is, though, with the technologies I have recommended here, they all require serious development. We know in principle how they all should work, except possibly nuclear fusion, but we do not know how to put the technology into a useful form. Meanwhile, with the low price of oil there is no incentive. Here, the answer is clear: a serious carbon tax is required on fossil fuels. I would like to see the resultant money being at least in part spent on developing potential technologies. Maybe this is my personal bias coming through – the promising algal technology I was working on collapsed when fund-raising was scheduled for the end of 2007, and thanks to Lehmans, that was not going to succeed. I am not alone. I am familiar with at least three other technologies of which I had no involvement but looked extremely promising, but they ran out of funding. As a society, can we afford the waste?