California's Land Use Choices

Much has been made of “smart growth principles” and “smart energy policy” in California. But in reality, the assumptions which dominate and drive California’s land use and energy policies are seriously flawed. Failure to examine the quantitative realities that ought to inform these policies, and adjust accordingly, will condemn Californians to a future much darker than many rational alternatives.

The three primary questions facing California’s policymakers are how best to manage California’s land, water, and energy. In all three, stark choices are faced, which can be illuminated by comparing four types of land use: High density new homes, low density new homes, corn ethanol farms, and solar thermal power stations. In all four areas, elementary quantitative analysis may reveal surprising results.

There are 37 million people in California. Assume the population will grow over the next 25 years to 50 million people – an increase of 13 million. There are 158,000 square miles of land in California, and about 40,000 square miles of that area is farmland. So if 13 million people were settled on new land, not infill, at a high density of 20,000 people per square mile (at 3.5 people per household that is 9 residences per acre – an amount easily achieved according to current “smart growth” principles), it would consume 1.6% of California’s farmland, or a mere 0.4% of California’s total land area. Even that miniscule expansion is a constant, nearly impossible fight in today’s political environment – the conventional wisdom claims “infill” within the footprint of existing cities is supposed to accomodate all new growth!


If on the other hand, 13 million new Californians all chose to live in very low density developments – something that is extremely unlikely since many people prefer living in urban centers where the population often exceeds 50,000 per square mile – how much land would be consumed? Again the percentages are underwhelming. At a density of 2,000 people per square mile (less than one household per acre), literally 1/10th the “smart growth” densities, only 16.3% of California’s farmland will be lost; only 4.1% of California’s total land area. It is true that losing 16% of California’s farmland is not trivial, but nor is it overwhelming. And even in a scenario where new low-density developments are encouraged, most new development will not occur on farmland.

When considering land use, however, what sort of farmland is being lost? If agricultural land growing food crops is being lost, that is arguably a problematic tradeoff. But California is rushing headlong into development of a subsidized corn ethanol industry. So what are the water and energy tradeoffs between land for homes and land for biofuel? Let’s assume low density homeowners use a whopping 2,000 gallons per residence per day per person – an absurdly large amount; four times what the average resident uses in Los Angeles County. At the population density of 2,000 people per square mile (3.5 people per residence), it would take 3.7 cubic kilometers of fresh water per year to supply 13 million people living on 6,500 square miles of new low density residences.

That sounds like a lot until you consider the water requirements for 6,500 square miles of corn ethanol. A conservative estimate is that every gallon of corn ethanol – in arid regions like California’s Central Valley – requires at least 1,000 gallons of crop irrigation per season. Since corn ethanol, very best case, yields 5,000 gallons per acre per year, the yearly water requirement for 6,500 square miles of cornfields, instead of low density housing, is 5.2 cubic kilometers of fresh water – nearly twice as much as for housing!

And how much energy would allocating all this land and water to corn ethanol buy us, anyway? Californians consume 29 billion gallons of petroleum per year. Planting 6,500 square miles of corn ethanol will yield, best case, 1.4 billion gallons of ethanol, which at 80% the energy density of gasoline, equates to 3.7% of California’s current petroleum consumption.

On the other hand, utility scale solar thermal electric power can easily yield 5 watts per square foot – including the balance of plant. Moreover solar thermal power is rapidly becoming competitive with fossil fuel, and decentralized and utility grade electrical storage is almost here. At this energy density, 6,500 square miles of solar thermal installations would yield 123 gigawatt-years of energy per year, which is easily more than 100% of California’s current electricity and petroleum production combined.

So be careful what you want, policymakers, as you continue your ongoing destruction of every beautiful outlying suburb in our beautiful state with ultra high density “infill” developments, and at the same time subsidize corn ethanol – all in the name of being green.


5 Responses to “California's Land Use Choices”
  1. Chris says:

    I would have to agree with you on this point. I believe that ethanol is a poor alternative to gasoline. I don’t like gasoline or any petroleum products used for transportation or energy creation. I would much prefer solar power and all-electric vehicles. And if the country was really serious about corn-based ethanol than the states of Indiana and Illinois alone could produce enough corn to supply the whole country’s demand. And that could only be the excess that is not sold as food type products for humans or livestock. If the state wants to subsidize something useful, than go solar. Solar installations for power generation would be of much greater importance to the continual population growth of California and to the acceleration of solar power technology as a whole. To make solar competitive with fossil fuels the price must come down and that will only happen with greater solar efficiency and mass production to decrease per unit cost.

  2. Ed Ring says:

    Chris: Indiana has 36,420 square miles, Illinois has 57,918 square miles – if you include parts of Lake Michigan. These two states together total 94,338 square miles. If you planted 100% of this area with corn for ethanol, and you got a yield of 5,000 barrels per square mile (a pretty high yield), you would have an annual ethanol production of 471 million barrels, which at 80% the energy density of gasoline, will displace 377 million barrels of petroleum per year.

    Since the USA consumes about 20 million barrels of petroleum per day, planting 100% of the area of Indiana and Illinois in corn for ethanol would offset 19 days of US petroleum consumption, or 5.2%. Not much there.

    I do think there is an argument in favor of corn ethanol if it is grown on land where summer rainfall alone provides sufficient crop irrigation, as is generally the case in Indiana and Illinois. There is even an argument for subsidies for corn ethanol (if it doesn’t require irrigation water in a water-stressed state such as California) insofar as it keeps the money in the US instead of purchasing imported oil.

    In my opinion however there is no rational argument for subsidizing corn ethanol crops in California.

  3. Matt Schmidt says:

    Of course you have to support the EcoWorld site with paid advertising, but I’m perplexed by the appearance of GM’s “go yellow’ ads promoting corn-based E85 ethanol (including reference to reduced dependence on petroleum). This seems dissonant with your general tone about the relatively poor economics of ethanol. Does the need for revenue override principal, or have I misread the site’s position?

  4. Ed Ring says:

    Matt: First of all, in regions of the United States where abundant summer rainfall can provide 100% of crop irrigation, the economics of ethanol are not beyond debate. While even in a water rich area, ethanol requires subsidies, those funds are going back into the American economy, instead of being used to import oil. So dollar for dollar, the macroeconomic impact of subsidized ethanol may well be in the national interest.

    Furthermore, while it is clear corn ethanol will not make a huge dent in oil imports, it is not a bad idea to have diversified sources of fuel and decentralized sources of fuel refining. In a national emergency, having the diversity of fuel options offered by decentralized ethanol refineries may make the difference between ambulances and fire engines doing their job, or sitting idle because there isn’t any gasoline.

    While we are not necessarily 100% in agreement with corn ethanol – we certainly don’t think it makes ANY sense to grow it in a water stressed state like California, we do think it is better to send fuel dollars to, say, Iowa, instead of overseas.

  5. Rothy says:

    Corn yields 1/2 the ethanol per acre as a sugar cop. WHY is everyone pushing corn so much when it is a nutritional disaster to the soil and produces so much less ethanol than sugar?

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