Eliminate animal husbandry to stabilize greenhouse gas levels for decades to come. The idea of “all vegetarians” was launched again a few days ago. Not by any candidate for the upcoming presidential election. No. By a team of American researchers. So Futura asked itself the question of the relevance of this idea and Marc Benoit, research engineer at the National Research Institute for Agriculture, Food and the Environment (Inrae), agreed to provide us with some response elements.
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[EN VIDÉO] The (over)consumption of meat, bad for the climate Livestock farming is a sector that emits a lot of greenhouse gases. It is also responsible for a large part of deforestation. Thus, the consumption of meat, especially in excess, appears to be bad for the climate.
In metropolitan France, theAgriculture is responsible for approximately 19% of emissions of greenhouse gas (Citepa 2021). This is less than the transport sector, which is around 30%. But it’s still substantial. And livestock, alone, accounts for half of these emissions – 48% against 40% for crops and 12% for machinery associated with the activity. So much for the numbers. It remains to understand what is hidden behind and above all, to what extent it would be possible to reduce greenhouse gas (GHG) emissions from the livestock sector.
Already in 2016, researchers argued that adopting a vegetarian diet globally would reduce food-related emissions by up to two-thirds. And, at the start of 2022,other researchers suggest that a 15-year gradual transition to a diet without animal products could stabilize GHG emissions for the next 30 years. ” All vegetarians in 15 years, it’s impossible”says Marc Benoit, research engineer at the National Research Institute for Agriculture, Food and the Environment (Inrae). “The question we are asking ourselves today at Inrae is to know what would be the optimal share of livestock in the human diet to respond to a certain number of issues. Among which is that of climate change. »
Let us first recall that there is no doubt today that animal husbandry has a deleterious effect on the climate. Notably because it emits lots of methane (CH4), a powerful greenhouse gas. Hence the increasingly widespread idea of limiting – more or less drastically – its scope.
“Eating animals is also not optimal. We feed five to ten times fewer people with a ruminant than with the cereals and oilseeds that were used to feed the animal., explains Marc Benoit. This explains why in France, organic consumers use less agricultural land than conventional consumers. Even though yields are around 20% lower. “Because their consumption of proteins animals is less. » There are therefore strong arguments in favor of reducing the share of livestock in agriculture.
Yes to breeding, but to reasoned breeding
“But if we hope to produce more cleanly, pesticide freewithout herbicides, in particular for major cereal crops, we will have to naturally break the cycles of diseases and pests and, to do this, make these crops more complex”, explains Marc Benoit. By lengthening the rotations. And including fodder crops. “The best thing, then, will be to encourage breeding, herbivores in particular, to enhance them. »
We understand better why the Inrae engineer mentioned in the introduction, an optimum to be found. The calculation was made for the particular case of the Netherlands. The researchers (H. Van Kernebeek and para., 2014) recommend a 12% share of animal protein in the Dutch diet. At less than 12%, local agriculture would come to occupy more land to feed the same population.
“Globally, the optimum would be around 25%”, says Marc Benoit. Because the figure varies from country to country. “In the mountainous regions, the animal is interesting. It takes advantage of pastoral areas in which it is anyway impossible to produce food for humans. » There would thus be in the world, no less than 1.3 billion hectares of agricultural land not cultivable. Surfaces that some call for afforestation. To store a little more than carbon.
“It’s a risky bet. Firstly because without animals to maintain these landscapes, the brush will take over., comments for us Marc Benoit. This increases the risk of fire. A risk already increased in the context of global warming. “And we must remember that the biodiversity flourishes more in semi-open environments such as those maintained by herbivores. Not in the forests ». Not to mention the social question: what will become of the tens or even hundreds of millions of breeders in these areas?
Reduce our meat consumption to feed everyone with cleaner agriculture
Thus, asking everyone to convert to vegetarianism would not only be impossible, but also totally counterproductive. And despite growing environmental, nutritional and even ethical considerations, the share of animal products in the diet of an average Frenchman remains today at 60 to 70%. “The optimum would probably be to divide meat consumption in Western countries by three or four. It would help us to feed everyone with cleaner agriculture. »
In developing countries, the question arises again in a different way. “In Africa, there are real nutritional challenges”, the Inrae engineer reminds us. We must not lose sight of the fact that, if in the countries of theOECDfarms have an average of 20 hectares per agricultural worker, “nearly 94% of agricultural workers (figures CAM) are located in Africa or Asia, on farms of less than 2 hectares. » Very small farms which integrate a minimum of breeding. “Because if livestock farming can have a deleterious effect on the climate, it also provides many services. » The animals, as we have already mentioned, consume the co-products of the farm. They can also, thanks to miniature methanizers, supply the gas that will be used for cooking. Sometimes even the dung — when it is not redistributed on the land for fertilization — used for heating a room or cooking. And above all, in these countries that are much less mechanized than ours, animals provide valuable assistance at work.
A perspective that once again allows us to realize that the question is not simple. In our Western countries, meat consumption is excessive. This puts our climate at risk. Removing breeding would help solve this problem. “But, at the global level, there are economic, social, land occupation and service issues on which we cannot close the doors. eyes if we want to do sustainable development concludes Marc Benoit. For each country, it is necessary to work towards an optimum share of livestock farming in agricultural activity which will make it possible to feed everyone without deplete resources of the planet. »
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