All Aboard the “Eat Less Meat” Bandwagon

One of the main criteria for publishing scientific research is that it should be novel, yet not a week goes by without yet another paper concluding that we have to reduce meat consumption in order to mitigate climate change. That’s the headline in media coverage relating to the latest paper from a researcher at the The Woods Hole Research Center (published in Environmental Letters), which examines nitrous oxide emissions (a highly potent greenhouse gas (GHG)) in 2050 under various scenarios.

It’s an interesting paper, not least for some of the assumptions buried within the model. Based on data from the FAO, the authors assume that meat consumption will increase by 14% in the developed world and 32% in the developing world by 2050. Coupled with the predicted population global increase (from the current 7 billion to 8.9 billion in 2050), it’s not surprising that a 50% reduction in meat consumption would be predicted to have a significant effect on total GHG. It’s rather akin to suggesting that each person will own two automobiles in 2050, so we should reduce car manufacture.

However, the more striking result is buried in Figure 1, showing that if efficiency of manure management and fertilizer application were improved, this would have a more significant effect on GHG emissions than reducing meat consumption. Given the considerable improvements in cropping practices, crop genetics and yields over the past 50 years there is absolutely no reason why this should not be achieved in the next 40 years.

Alas, a headline suggesting that agriculture needs to continue to improve manure and fertilizer efficiency just isn’t as sexy as the “eat less meat, save the planet” message so often propounded by the mass media. They say that bad news sells – it’s a shame that the lay press are so enamored with messages that denigrate ruminant production, rather than taking a broader look at the options available for mitigating future climate change.

*Thanks to Jesse R. Bussard for bringing this one to the forefront of my “to do “ list.

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Is Corn the Soylent Green of the Future?

I recently had the pleasure of watching the 1973 movie Soylent Green starring Charlton Heston. I won’t spoil the ending for those who havent seen it, but the overarching premise of a big company controlling the food supply to an hungry, overcrowded future population strongly resembles some of the current claims made by the more vehement foodies. The anti-animal-agriculture activists appear to have a similar agenda – if only food production was “sustainable” (a word with a million definitions) without any of those “factory farms (that) pose a serious threat to health” and red meats that “have been linked to obesity, diabetes, cardiovascular disease, and certain types of cancer“, life would be much sweeter.

So what’s the answer? It’s very simple. All that animal feed could simply be fed to humans. According to Pimentel at Cornell University, 800 million people could be fed with the grain that livestock eat in the USA each year. If we ignore the fact that field corn (fed to livestock) is not the same as sweet corn (the corn on the cob that we eat), and assume that field corn could easily be processed into a human foodstuff, Pimentel is right.

Given the average human nutrient requirement (2,000 kCal/day) and the energy yield of an acre of shelled corn (14.5 million kCal), one acre of corn (at 2011 US yields) could supply 20 people with their energy needs (see table below). On a global basis, we currently harvest around 393.5 million acres of corn, therefore we could supply the entire current global population (7.003 billion) using only 90% of the global corn area. Of course that’s assuming zero waste and US crop yields. If we use a more realistic scenario with global corn yields (85 bushels/acre) and 30% food wastage, we can only feed 12 people per acre and would need to increase current corn acreage by 121% to produce enough food to supply the current population. So what happens by the year 2050 when the population is predicted to reach 9.5 billion people? Assuming that we continue to see increases in yield proportional to those over the past 30 years (30% increase in US yields since 1982), that yield increases are exhibited globally, and that we can cut food waste to 10%, we could feed 15 people per acre and we’ll need to increase corn acreage by 79% to provide sufficient corn to feed the global population.

If our dietary requirements can be met by corn alone, the increase in land use won’t be an issue – land currently devoted to soy, peanuts or wheat can be converted to corn. Yet this simplistic argument for vegetarian/veganism suffers from three major flaws. Firstly, it assumes that the global population would be willing to forgo lower-yielding vegetable crops that add variety to the diet – where are the artichokes, kale or radishes in this dietary utopia?

Secondly, as noted by Simon Fairlie in his excellent book, converting to a vegan monoculture would significantly increase the reliance on chemical fertilizers and fossil fuels due to a lack of animal manures. Given current concern over dwindling natural resources, this is an inherently unsustainable proposition.

Finally, corn is currently vilified by many food pundits. The suggestion that our food supply is controlled by corporations who force monoculture corn upon hapless farmers who are then faced with the choice of complying with big ag or being forced out of business are the purview of food pundits (e.g. Michael Pollan and Joel Salatin) and documentaries such as Food Inc. and King Corn. Not a week goes by without another Mommy blogger or journalist publishing an article on the dangers of high-fructose corn syrup, often concluding that if only this ingredient was removed from our food supply, childhood obesity and pediatric type II diabetes would cease to be an issue for little Johnny and Janie pre-schoolers of the future.

It’s frighteningly easy to visualise the Soylent Green-esque vegan future, whereby food is doled out in pre-measured quantities according to dietary requirements – yet what happens when the whistle-blower of 2050 proclaims “it’s made from CORN!”?

Can Population Control Shrink the Yield Gap? Developing Solutions for Developing Regions

A recent article by Andrew Jack in the Financial Times (the iconic pink-colored newspaper carried by all self-respecting business men on London tube trains each morning) reports that developing countries in Africa will be responsible for the greatest increases in population growth over the next 90 years, with the global population predicted to hit 10 billion by 2100. Given the number of dire predictions currently being bandied around regarding population increases, food demand and climate change it’s easy to become blasé and dismiss it as just another issue that will be solved by the next generation. After all, what difference can we possibly make to rural communities in developing countries?

Rises in per capita are predicted for developing countries over the next century and as Andrew Jack notes, increasing affluence results in improved healthcare, urbanisation and a decline in birth rates. Nonetheless, this pattern is not being currently being exhibited by regions in Africa and S. Asia, which are unable to improve per capita income as population increases overcome economic growth.

So how do we curtail the rise in population growth? Even in a developed country such as the USA, mentioning the politically-charged phrase “population control” often leads to an uncomfortable silence, images of an Orwellian constraint on family size (1 child good, 2 children bad?) or debate over the rights and wrongs of abortion. Yet simply providing access to contraception, considered to be an inherent human right by many women in the developed world, could conceivably (pardon the pun) improve future sustainability.

Reducing the number of children born in developing countries would improve female health and lessen the burden on economic and environmental resources placed by increasing population size. This would be a crucial step forwards in mitigating future food shortages, yet it does not solve the underlying problem. One of the major drivers behind population growth is parental reliance on support from the younger generation. As discussed in Jared Diamond’s excellent book “Guns, Germs and Steel“, higher birth rates potentially allow for a greater number of children to work on the land and improve societal stability. However, the promise of  future affluence is a major stimulant that causes young people to migrate from rural areas to urban regions that are already suffering from significant overcrowding.

A considerable yield gap exists between developing and developed countries, both in terms of animal and crop production. If productivity could be improved and the yield gap reduced, food security would improve in rural areas with positive effects on per capita income and infrastructure, and potential reductions in the number of inner-city migrants. Nonetheless, the major question remains unanswered – how to improve productivity?

If we use dairy farming as an example, a recent report from the Food and Agriculture Organisation noted a negative relationship between productivity and carbon footprint – as we move across the globe from developed to developing regions, productivity decreases and the carbon footprint per kg of milk increases (see graph). Carbon can also be considered a proxy for land, water and energy use, thus reduced productivity increases both resource use and environmental impact. The logical conclusion would therefore be to implement systems and management practices currently seen in N. America, Europe and Australasia in an attempt to educate farmers in S. Asia and Africa. However, sustainability cannot be improved by implementing a one-size-fits-all solution, but calls for a region-specific approach.

Identifying traits within indigenous and imported animal breeds and plant varieties that will make the best use of available resources allows development of production systems that match environmental, social and economic demands. Further implementation of continuous improvement and best management practices in developing countries is crucial in order to improve affluence, reduce population growth and mitigate environmental impact both now and in future. However, this is not a situation that can simply be solved by improving yield per acre, but requires a multifactorial approach coordinating population control, education, food security and human health and welfare. Providing contraception without a concurrent effort to improve agricultural productivity will fail in its prophylactic intent to control either population growth or world hunger.