The global demand for protein is rising rapidly. This is largely due to more disposable income in emerging economies and changing dietary preferences in much of the developed world [1
]. Dire predictions have been made about a global food crisis for 2050, with global population exceeding nine billion and the effect of more extreme weather on farm productivity around the globe [2
]. Global food security is exacerbated by inequitable distribution between rich and poor countries [6
]. Nowhere is this inequality more apparent than in access to protein, where grains are increasingly being fed to meat animals, while the world’s poorest people struggle with chronic hunger and poor nutrition. The need to address climate change is the added imperative that pushes food production into a perfect storm situation [7
]. As the global community awakens to the reality that all countries and all sectors must do whatever they can to reduce greenhouse gas (GHG) emissions [8
], all agricultural products can expect to be evaluated on the basis of their carbon footprints (CF). Since livestock account for 14.5% of global GHG emissions [9
], consuming fewer livestock products could significantly lower these emissions [10
This CF scrutiny will be particularly intense for livestock products, which are estimated to be responsible for 18% of greenhouse gases [12
]. Dyer et al.
argued and demonstrated that the fairest way to assess the CF of livestock production was by protein-based GHG emission intensity [13
]. This paper focusses specifically on protein production from both plant and animal sources in Canada as a distinct challenge from food security. It determines how much plant sources can help Canada produce more protein with lower GHG emissions. This paper will quantify the CF of these products and describe three indicators suited to this task. The diversity of protein sources and differences in livestock types and production systems among the Canadian provinces result in significant differences among the CF of protein from those provinces. Therefore, a second goal was to determine how these spatial differences affect the protein CF distribution across the Canadian provinces.
Protein is a macronutrient necessary for the proper growth and function of the human body [14
]. Although there is some debate over the amount of protein a person needs, a deficiency in protein leads to muscle atrophy and impaired functioning of the human body. Whitbread [14
] recommended that the current daily intake for protein should be 46 grams for women aged 19–70 and 56 grams for men aged 19–70. Using food balance sheet data from the Statistics Division from the Food and Agriculture Organization of the United Nations, the ChartsBin Statistics Collector Team [15
] defined world daily intake per capita of protein as 77 g, ranging from 100 g in the developed world to as low as 55 g/day in the developing world.
While small grain cereals (particularly hard red wheat) produce proteins, this type of protein is considered to be incomplete, because it lacks some of the amino acids that are found in animal proteins and which are essential to the human diet [16
]. Legumes (or pulses), however, produce complete proteins. Therefore, plant and animal agriculture can be compared on the basis of their respective supply of “complete” protein. Beans and other legumes are a critical source of protein in many parts of the world [14
]. They are an inexpensive food, high in fiber, calcium and iron.
Trends and patterns in GHG emissions from livestock and field crops in Canada are often discussed simply on an east-west basis, because agriculture west of the Great Lakes is dominated by the Prairie Provinces, while east of Lake Superior, it is the north shore of Lakes Erie and Ontario and the Saint Lawrence River basin that are the dominant farming regions. To discuss regional differences, the provinces were grouped so that the Atlantic Provinces (AP) (treated as one province), Quebec (QC) and Ontario (ON) were defined as Eastern Canada, and Manitoba (MN), Saskatchewan (SA), Alberta (AB) and British Columbia (BC) were defined as Western Canada. Given the size of Canada and the additional small, but distinct, farming regions in the coastal provinces, these trends and patterns also need to be assessed on a sub-provincial basis, as well as a provincial level. However, reporting results on a sub-provincial scale was beyond the scope of this paper.
The conclusions drawn in this paper relied on all three of the indicators described above. Hence, Indicator 3, the protein-based GHG emission intensity, is most effective when used in conjunction with the two land use indicators. The provinces that ranked best under Indicator 3 were those with the largest areas in non-LS pulses, which is consistent with the lower CF of pulse protein than animal protein. The province ranking the lowest, Alberta, depended heavily on beef and had a relatively small area in pulses. The two coastal provinces (AP and BC) were almost as low as Alberta, which was to be expected, since neither had any reportable non-LS pulse areas.
The results of this protein comparison identified soybeans as having the lowest CF and as being the most effective land use for protein production. In spite of far greater areas in pulses in Saskatchewan, the lower PCF of dry peas and lentils allowed Ontario, the leading soybean producer, to be the highest protein-producing province in 2006. However, caution is needed when an analysis points to just one crop as a wonder crop or super food. There are both nutritional and environmental risks from creating a global-scale dependence on just one crop. On the other hand, the benefits of soybeans derived from this assessment did not include the additional value of that crop as a potential source of biodiesel feedstock [34
] or a cooking oil [35
], a consideration that would have lowered its net CF even further.
Much of the methodology described in this paper could also be applied in other countries with developed agriculture. In Canada, the two provinces with the lowest CF for protein production, Ontario and Saskatchewan, both on an area and protein basis, also had the largest pulse production. This result suggests that developed countries can reduce the CF of their capacities to produce protein by increasing their consumption and export of pulse protein rather than by producing more livestock. Such extrapolation to other countries, however, should be limited to those regions that do not depend heavily on extensive grazing, because cattle raised primarily on grass have a different CF than cattle raised in the more intensive beef operations typical of North America. In many parts of the world, the soil under the grazing land may not be suitable for annual cultivation, and converting such land to annual crops could lead to serious land degradation.
The two issues identified at the start of this paper, global protein supply and a lower CF for protein production, can both be achieved through a shift in land use towards pulses and away from livestock. Although this analysis also suggests that ruminants are less efficient than non-ruminants with respect to Indicator 3, it should be cautioned that only ruminants can convert perennial forage to protein. However, keeping cattle on low roughage diets (as in feedlots) negates much of the ruminant advantage. The three indicators, particularly 2 and 3, address the global challenges of demand for protein in the human diet and minimizing the GHG emissions from protein production. While expressing the protein production in terms of satisfying global nutritional requirements went beyond the assessment of the three indicators discussed in Table 3
and Table 4
, this interpretation has potential food policy value. Inside the farm gate, findings, such as described in this paper, should link with the LCA of whole life cycles when more specific protein products are being assessed.
Although this interpretation is not likely to influence the market strategies of the livestock industries, it should help to position Canada’s role in the global protein supply chain. The PPY concept may be a useful index for evaluating this supply chain on a global scale. The low CF of Canadian soybeans relative to soybeans imported from places where deforestation is a big factor in their CF [38
] (such as Brazil) should also help to establish this position for Canada. Since this paper was not aimed at marketing of Canadian pulses, tofu and other meat analogues manufactured from pulses could be removed from the CF calculation of pulses and the scope of this assessment. As a protein supplement to food aid, pulse protein enjoys another advantage over livestock protein, because it can be shipped dry, stored without refrigeration and is usually ready to eat right after boiling.
It must be acknowledged that it is relatively easy to find literature and Internet sources that extol the potential environmental and social benefits of replacing livestock protein with pulse protein. It is somewhat surprising, however, just how much the pulse proteins out-performed the livestock protein as rated by all three indicators within the farm gate. However, the true value of this assessment was not in repeating what some might see as the obvious, but in quantifying the process into a repeatable and scalable package. The level of integration in this modelling system brought all of the variables into one quantitative process (inventory model) that could be applied directly, or rebuilt, in many other countries. Although only 2006 was assessed in this paper, having one computational package will facilitate temporal flexibility by allowing the findings for 2006 to be compared to past or future years (when those data become available) or to hypothetical years that reflect policy scenarios.
In undertaking the second goal of this paper, the disaggregation to provinces, the spatial scalability of this methodology was able to highlight the impact of the inter-provisional diversity of protein sources in Canada. The analysis described in this paper could be applied on a sub-provincial scale, such as ecodistricts and census agricultural regions (CAR). Eventually, international treaties encourage all countries to adopt measures that will mitigate GHG emissions in all sectors. Implementation of such measures for Canadian agriculture will require communication with farming communities on sub-provincial scales (either ecodistricts or CARs). Assuming that the provincial scale inputs used in this assessment are available at these finer scales, this assessment could be repeated at those scales.