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Graph of the year 2013: Proportion of calories delivered as food

Although already well into 2014, here is my personal “Graph of the Year 2013”: The proportion of produced calories that are delivered to the food system.

CalorieDeliveryFraction

Source: Cassidy et al., Environm. Res. Lett. 8 (2013) 034015

The figure is one output of a study carried out by Emily Cassidy and colleagues of the University of Minnesota that was published in the journal Environmental Research Letters.

The researchers approach the challenge to provide sufficient amounts of food amidst global population growth, increased biofuel production and changing dietary preferences from a different angle than is widely done. Instead of estimating the increases in farm prodution necessary to satisfy the rising needs for agricultural products they analyze the current allocation of the world’s crop production to different uses.

According to the study, only 55% of global calorie production is directly used for human consumption. The remaining 45% serve either as animal feed or other uses such as industrial purposes and biofuels. In consequence, 41% of all calories produced are lost from the global food system. While the crops grown on one hectare could satisfy the caloric needs of 10 people, currently only 6 people are fed.

The graph gives a global overview of the fraction of the calories delivered to the food system per calories produced.  It shows that the losses from the food system are highest where livestock production, industrial uses and biofuels production are of a high importance. These are mainly the most affluent regions (e.g. North America, Europe), but also the regions in which agriculture is oriented at the production of animal feed for the global market (e.g. Eastern South America).

The arguably most important conclusion from the analysis is that if the crop calories used for feed and other uses were shifted to direct human consumption, up to around 4 billion more people could be fed. Or, perhaps easier to achieve, already small changes in the allocation of crops to animal feed and biofuels could significantly increase global food availability.

 

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Is a fertilizer revolution the right recipe for African agriculture?

It is often argued that to increase its farm yields and close its yield gap, Africa needs a new Green Revolution, based on the expanded use of fertilizer. An intriguing analysis by Pablo Tittonell of Wageningen University, however, tells a somewhat different story (find it on p.17ff. in Tittonell’s inaugural lecture at WUR.

In an on-farm research program carried out in Western Kenya, Tittonell and others compared maize yields on the fields of 60 households under different management regimes. A part of the plots was managed by the farmers themselves, with or without use of fertilizers. Another part was managed by researchers without the use of fertilizers, only taking care of the right planting time and plant spacing, frequent weeding, and using certified local cultivars. A third part of the plots was managed by the researchers with the use of N-P-K fertilizers.

MaizeYields

Source: Taken from Tittonell (2013).

The figure shows the striking result that the plots managed by researchers even without fertilizers had higher yields than the plots managed by the farmers, thus illustrating the potential of proper agronomic management. In particular with rising distance from the homestead this potential is high.

On the other hand, the figure also shows that N-P-K fertilization has an even higher potential for increasing yields. However, the researchers also argue that, given the current quality of the road network, bringing the amounts of fertilizers required to obtain significant yield increases at scale to the rural communities would not be feasible .

The analysis raises a number of interesting questions. The overarching question is – taking optimized agronomic management and the use of higher amounts of N-P-K fertilizers as alternatives – what is the better alternative?

Read more…

Are fossil-based assets overvalued?

Among the more fascinating books I had the pleasure to read lately is 2052-A Global Forecast for the Next Forty Years by Jorgen Randers.

In this work, which is conceived as a report to the Club of Rome and a follow-up study to the famous Limits to Growth of 1972, Randers describes what he believes to be the major trends to shape the global future of the next forty years and presents a quantitative analysis based on a global forecast model.

One of the predictions that called my attention is that fossil-based assets, e.g. share prices in companies that produce and sell fossil-based energy, would suddenly lose their value. This would be a consequence from the fact that fossil-energy companies are priced based on the reserves of fossil fuels they control. This pricing does not take into account that in the coming decades demand for fossil fuels will decline due to their substitution by renewable energy and the limits to CO2 emissions imposed by climate change, hence the shares are overpriced (see p. 343 of 2052).

Randers states that he would “agree with the analysts that it will take time before this realization dawns on the investors”.

All the more interesting is an article Unburnable fuel published in this week’s edition of The Economist. The article compares the amount of proven reserves of fossil-fuel companies with the amount that still could be burnt without exceeding the limit of a 2°C increase in global temperatures and concludes that a substantial part of those reserves might never be allowed to be used.

Based on figures from a (not publicly available) report by HSBC Global Research, the value of reserves that would be unusable if policies to limit the rise in temperatures to 2°C would be implemented amounts to around 2% of the market capitalisation of Shell, around 6% for Total and BP, and over 16% for Statoil.

Finally, the article argues that markets are not adequately taking into account the risk of a devaluation of the fossil-based assets. At the same time, by failing to design an effective policy framework to limit global warming, policy makers are also not seen to take into account the risks of climate change.

Now, it will be interesting to see whether, to which extent and when investors start taking into account the low future value of fossil fuel reserves, and how strong the effect on share prices of fossil fuel companies will be.

Is going by bike better than being vegetarian?

Being vegetarian is perhaps one of the best lifestyle choices you can make. And one of the strongest argument for making this choice perhaps is that, depending on the type of meat and the production system it comes from, 1 food calorie from meat need by between 2 to 10 times more energy (I don’t know the exact numbers, but they are somewhere out there) than one from a plant based diet.

Not surprising that I was delighted to find the link to economz – visualizing your carbon footprint on the Food Tank website. economz is a visualization project with a very nice online tool which allows you to compose alternative meals from different popular food items and visualize the carbon foodprint of those meals in terms of car miles traveled.

Now, if I prepare a meal consisting of a steak with french fries and some tomatoes and broccoli (for the vitamins!) I learn that eating this dish once a day for one year corresponds to 3794 miles driven by car. Wow! A more reasonable and vegetarian dish with tofu, rice, broccoli and tomatoes is worth 1087 miles. This means that in this scenario going vegetarian (only for lunch) would safe me 2707 miles per year. That’s indeed very nice.

But well, I think again and what comes to my mind is that many people actually use their car a lot more every year and in fact those 2707 miles might not be that much. I have no idea about the average annual car use in a more or less developed society. But I can take my own daily commuting as a reference, which is around 15 miles. Assuming that I do all this by car at the moment (which I don’t), I would need to leave the car at home and take the bike on 180 days of the year to save the additional emissions from a steak-and-chips diet. That is substantial, and my tentative conclusion is that being vegetarian is about as good as going to work by bike during 75% of the year. More or less…

Work less and slow climate change. Sounds good, isn’t it?

A recent paper by the Center for Economic Policy Research (CEPR) explores the question to which extent a reduction in work hours can contribute to slowing climate change.

The author uses a subset of the IPPC’s illustrative scenarios and simulates the impact of a reduction of work hours by assuming that hours worked fall by 0.5% per year in each scenario. He links this reduction in work hours to carbon emissions through the assumption that a 1% increase in hours worked per employee results in a 1.5% increase in carbon footprint.

As a result, between 35 and 70% of not already locked in warming would be avoided. However, this figure would change with alternative assumptions on the link between a reduction and work hours and carbon emissions and with expectations regarding employment effects.

Sure, the modeling approach as well as the assumptions may leave space for critical discussion. However, the piece is a nice and interesting analysis, which fits well into the debate on degrowth. And it can be seen as complementary to another recent article, published by Jørgen Randers in the Guardian: Should paid work be rationed? In that article, Randers also gives some input for answering the inevitable question what would happen to emissions if people with more free time opted to travel or watch TV (which requires electricity) instead:

Shorter working weeks, with more time spent reading and pottering in the garden, would help stabilise the use of planetary resources.

Putting poo safely into the right place–the fields!

In a contribution to the Agriculture and Ecosystems Blog, Fred Pearce describes our current practices of dealing with human excrements – mainly the discharge of waste water from urban centers to water bodies – as “one of the modern world’s worst, but least discussed, resource failures”. Given the high contents of nutrients in sewage and the negative impacts their discharge unfolds on ecosystems he may be absolutely right.

And he rightly emphasizes that there is a big potential in the better use of waste waters, but not without mentioning the potential risks to public health involved. And while recognizing that the informal collection and subsequent use of sewage in agricultural production is a reality in many places of the developing world, he criticizes that policy makers and researchers alike either prefer not to deal with the issue or tend to contain the practice. Instead they should recognize the potential, but without losing the need for proper regulation and for the use of adequate technologies out of sight.

The question is, of course, whether this will happen. It seems that a necessary condition is that obtaining the resources embodied in waste water from alternative sources of supply becomes more expensive than water treatment and associated activities (e.g. setting up an adequate institutional framework and the like). Pearce mentions the examples of countries located in arid regions like Israel, Mexico and Tunisia where waste water is getting recycled. Rising energy prices may also contribute, directly and indirectly through higher costs for synthetic nitrogen fertilizers. Or increasing scarcity of phosphate rock (see, for example, a paper by Cordell et al.) may lead to higher prices for phosphorus fertilizer and contribute to new thinking in that area.