I spend way too much on my newspaper. 200€ a year, just to get a weekly paper. Granted, it’s about 10m² just on one page and it’s as thick as your average Bible, but still… For those of you who don’t know it, I’m talking about the German newspaper “Zeit”. It really is excellent, I just don’t have the time to read it every week. Not even close. So mostly, I just pluck out the articles that really interest me and go through those.

I won’t bore you with the article in “Zeit”, instead I’ll link to the article it references:

Rollin Stones: Global Warming’s Terrifying New Math

Short version: We’re pumping out much more CO² than we should. In fact, if we keep going at this rate then we’ll reach the red line (about 565 Gigatons until 2050, counting from today) in just over 18 years. (Today’s output ~31Gt/y, and 565/31=18.2) The problem: We’ve got about 2700Gt of CO² sleeping under ground in the form of coal, gas and oil.

So what are our choices? Depending on which side you listen to, there’s different solutions and different non-solutions. If you listen to the deniers then obviously there’s no need for a solution, the greens (note: NO capital G) say that solar/wind/bio-fuel and cutting carbon emissions (either through fuel economy or reducing the economy) are solutions but that nuclear power is a big no-no. The nuclear industry says that nuclear energy is the only solution.

If you’re reading this, you’re interested in what I think and say. Only to thrash it in the comments.

I will try to base my arguments on as much science as I can, though I warn you up-front: Not all here is hard science, some of it is soft science aka. humanities. In those cases, I present arguments and hope that they’re good enough.

A paper in 2004 (Pacala and Socolow, 2004) offers 15 solutions. (page 3 in the PDF, page 970 on paper) They can be categorized into two (or three) sections:

1) Improve efficiency

2) Use renewable energy sources or those of low CO² output

2.1) Use carbon sinks for fossil fuels

All of these 15 solutions are good and I can think of a few others, though they would be costly and possibly not as effective. So let’s focus on these 15. We’ll agree that 1 and 2.1 are all good, skip forestry (I’m very happy to see that on the list and it’s something that will take a lot of effort, sadly) and we’ll move to #2. Here we have five possible solutions: Biofuels, Photovoltaic, Hydrogen, Wind and Nuclear. I’ll try to very briefly deal with all of them, but I will completely skip Hydrogen because I know exactly nothing about its use as a fuel. If anyone could enlighten me in the comments, that would be much appreciated. It’s also noteworthy that both Hydro-electric power and tidal power have been skipped. The solution: There’s just so damn few of them, they make no global impact whatsoever. (Combined, they could potentially make up 1/4th of the power needed today, but that’s potential (i.e. sometimes not accessible and/or in natural reserves) and there’s huge costs involved.)

So let’s quickly look at those four remaining sources of fuel. I’ll start with Wind.

There are two ways of harnessing the power of the wind: Offshore wind farms and Onshore wind farms. Theoretically, wind power could give us more than enough energy. (see graphic 1) For the following figures, I will rely on this 2010 UK report as shown over at Wikipedia.
We can easily see that there is a huge difference in cost between onshore and offshore wind power: Offshore costs nearly twice as much. That’s also the reason why many companies are reducing their offshore wind power spending and are focusing on other means. For example, to achieve Britain’s goal of 15GW, this article suggests that you’ll need about 60$ billion. I don’t have that kind of money and neither do they, it seems.
The second way, onshore wind power, suffers problems of its own. Turbines don’t look good, they kill birds (though not nearly as many as people might want you to think), they’re unsafe… None of these are real problems, so we’ll skip those and get onto real ones. For this, I have absolutely no concrete number and must rely on what I was told by a high-ranking member in the Austrian ministry for agriculture. (includes renewable energy) If his numbers are correct, then onshore wind installations are pretty much used up. Austria produces about 1400MW from Wind Energy, or about 4% of our national consumption. Most countries produce between 1-7% of their energy from wind energy, in fact the EU average is 7%. Only countries with access to the ocean or with huge parts of unused land produce more than that. If I am to trust said person above, the EU average can rise to 10%, maybe 12%. It’s doubtful if more can be produced, simply because the turbines take so much space.
In short, Wind power can only do so much to curb carbon emissions. We must look further.
Having dismissed wind power as a viable alternative, we move on to biofuels. Contrary to common belief, not all of biofuels are generated by sugar cane or maize. This pop-sci article discusses the worth of forestry-related biofuels. Other researchers are looking into algae, fungi and other alternative biofuel sources.
Apart from the obvious problems with biofuels, like “food vs. fuel”, soil erosion, deforestation, impact on water, etc., there’s another huge problem: ERO(E)I or Energy Return On (Energy) Investment. Basically it means that you put in X amounts of energy and you get Y back. If Y>X, then you have a net gain. An EROEI of 1 means that you just break even: You get back what you put in, so there’s no gain. An EROEI of anything lower than 1 means you lose energy. Fusion, to take but one example, has an EROEI lower than 1.
OK, I see what you’re getting at. What’s the EROEI of bio-fuels? Murphy and Hall (2010) calculated three different EROEI’s:
1) Biodiesel with 1.3
2) Corn-based Ethanol with 0.8-1.6
3) Ethanol (Sugarcane) with 0.8-10
Most biofuels are simply too inefficient to make a big impact. We’d have to use vast swathes of land to achieve this. As Pacala and Socolow (2004) state:

Option 13: Biofuels. Fossil-carbon fuels can also be replaced by biofuels such as ethanol. A wedge of biofuel would be achieved by the production of about 34 million barrels per day of ethanol in 2054 that could displace gasoline, provided the ethanol itself were fossil-carbon free. This ethanol production rate would be about 50 times larger than today’s global pro- duction rate, almost all of which can be attrib- uted to Brazilian sugarcane and United States corn. An ethanol wedge would require 250 million hectares committed to high-yield (15 dry tons/hectare) plantations by 2054, an area equal to about one-sixth of the world’s crop- land. An even larger area would be required to the extent that the biofuels require fossil-carbon inputs. Because land suitable for annually harvested biofuels crops is also often suitable for conventional agriculture, biofuels production could compromise agricultural productivity.

Now I suggest, and you may or may not agree with that assessment, that this is simply unacceptable. We can not, nor should we, use biofuels to replace fossil-carbon fuels. Our greatest hope lies in electric motors. Biofuels can substitute a small sliver of current use, but if I were to make decisions I’d ban them outright.

This leaves us with the photovoltaic and nuclear options. To achieve 1/15th of today’s energy consumption, we’d need an area the size of Israel. (2mio ha = 20,000km² ~Israel or Slovenia) This wouldn’t be a problem if we could just plant them wherever we want, but we have to factor in watts per m² (Graphic 2), distance to destination, etc.

There is the added problem that photovoltaic costs quite a bit (see UK 2010) and again uses up large tracts of land. However, some people suggest it could make up 3-4 wedges (of 14-16 wedges needed) in this battle. I’m not so optimistic, at least not with the current state of technology. I’m all for using photovoltaic, don’t get me wrong. We’ve got some panels installed ourselves, as much as we could fit on the roof. However, they’re still not at a point where they’re effective enough to really take over. Currently, the most effective (and expensive?) cells have an efficiency of 44%. The average is far below that.
My conclusion: Solar power is by far the most promising of the above four mentioned, but we shouldn’t slack off on innovating them.

Last but not least, I want to turn  to nuclear power. I have previously already talked about how nuclear power is actually an incredibly safe alternative, the problem is just that people don’t know about that. I won’t go into that here. The above mentioned UK estimate (2010) calculates nuclear cost as being lower than tidal, offshore wind and solar power, and as being in the vicinity of other forms of energy. (onshore, coal, gas, biomass, etc.) By “in the vicinity” I mean that they overlap a huge amount, because of course there is some error margin. Nuclear’s EROEI is, depending on what kind of reactor you run, either lower than wind’s (10 vs 18) or much higher than wind (50 vs 18), but no matter what it’s far higher than either biofuels or photovoltaic (1.3 and 6.8 respectively).
There is then, only one real problem: Nuclear energy is a good way of battling CO² output, but on its own it’s not sufficient.

I will reserve a political discussion of these issues for a later time. I hope that I’ve made a few points clear:

• Some suggested solutions (biofuels, wind) may just be far less viable than advertised. These “solutions” should be avoided if at all possible or at least only implemented to a certain degree.
• Other solutions are difficult to talk about due to a lack of information (wind) or due to public opposition (nuclear), though that wasn’t mentioned now.
• Various solutions are needed to solve this problem. No one solution can fix this problem on its own. (Well, returning to our hunter/gatherer days might…) Greens are harming the cause (of reducing CO²) by not allowing nuclear energy to be part of the solution.
• I personally would go further and postulate that avoiding the oncoming crisis is ONLY possible if we use nuclear energy. I’d suggest going for 3-4 wedges instead of the 1 wedge suggested, if only to have a safety net. As soon as solar energy comes to the point where it can actively take over, we can turn off the reactors and lean back in contentment. But until then, nuclear energy is a vital part of the solution.