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농담/농-생태계

현대의 농업이 기후변화를 야기했다

by 石基 2017. 1. 12.
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As a new year dawns, it is hard not to be dazzled by the current pace of technological change in food and agriculture. only last month, news emerged of a crop spray with the potential to increase the starch content in wheat grains, allowing for yield gains of up to 20%. This development comes hot on the heels of major breakthroughs in gene-editing technologies – using a powerful tool known as Crispr – over the course of 2016.

A future of continually increasing food supplies and ever more sophisticated manipulation of agro-ecosystems seems to be upon us.

However, there is a risk that these technologies blind us to the very real problems facing modern agriculture – problems that are rapidly undermining the previous round of technological advances.

While global crop yields rose rapidly in the early decades of the “green revolution”, productivity is now plateauing in many regions of the world. A 2012 meta-study found that in 24%-39% of areas growing maize, rice, wheat and soybean, yields either failed to improve, stagnated after initial gains, or collapsed.

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Only slightly more than half of all global rice and wheat areas (57% and 56% respectively) are still experiencing yield increases. The areas where yields have stagnated include some of the wealthiest, most industrialised and most hi-tech production systems: more than one-third of the wheat crop in the US (mostly in the Great Plains) is affected, along with more than a third of the Argentine wheat crop, and harvests all across Europe.

Meanwhile, rice yields are plateauing in California and most European rice-growing areas. This trend is also evident in some 80% of rice crops in China and Indonesia – two of the world’s major rice producers. Worryingly, this may only be the tip of the iceberg. 

The reason the productivity of industrial agriculture is now under threat is because it has been systematically degrading the human and natural capital on which it relies. Pests, viruses, fungi, bacteria and weeds are adapting to chemical pest management faster than ever: 210 species of herbicide-resistant weeds have been identified. Meanwhile, synthetic fertilisers are fast destroying the soil biota and its nutrient-recycling potential. This creates a dangerous treadmill effect: increasing resistance leads to increasing pesticide use, generating mounting costs for farmers and further environmental degradation. This in turn requires additional doses of nutrient application to keep squeezing productivity out of the soils.

Meanwhile, food systems are responsible for up to 29% of global greenhouse gas emissions – and are therefore driving the climate instability that is itself the greatest threat to future agricultural productivity. A major chunk of these emissions come from large-scale monocultures and industrial animal feedlots in the global north, and from the loss of carbon sinks in the global south as land is cleared – often to make way for maize and soybean monocultures to export as animal feed.

Recent crop-breeding innovations may be impressive, but they do not hold answers to the most pressing question: namely, how to move away from industrial monocultures and the inevitable damage and vulnerability they bring. one new study suggests that a repeat of the Dust Bowl conditions of the 1930s – increasingly likely in a context of climate change – would wipe out 40% of US maize and soy crops, and 30% of wheat. What matters most is resilience. And resilience cannot be delivered without rethinking the fundamental principles of our food and farming systems.

The risk is that new technologies simply give industrial agriculture a new lease of life and delay the inevitable shift to a fundamentally different model of agriculture.

A viable alternative exists in the shape of diversified agro-ecological systems. In other words, diversifying farms and farming landscapes – replacing synthetic chemical inputs, optimising biodiversity and stimulating interactions between different species, as part of holistic and regenerative strategies to build long-term soil fertility, healthy agro-ecosystems and secure livelihoods.

Too often, these arguments are dismissed as technophobia. We are told that the opponents of industrial agriculture want to eschew technological advance and keep developing regions mired in non-mechanised, subsistence-style agriculture. However, this is a false dichotomy. 

A transition to diversified agro-ecological systems is needed, whether the starting point is industrial agriculture or subsistence-style farming. Moreover, the agro-ecological alternative is hi-tech and knowledge intensive – it requires complex synergies to be built and sustained between different crop varieties and species, and between different farming systems (mixed crop-livestock systems, for instance).

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The growing body of evidence reviewed by the International Panel of Experts on Sustainable Food Systems (iPES-Food) shows the huge potential of these systems to succeed where industrial systems are failing – namely in reconciling concerns such as food security, environmental and livelihood resilience, nutritional adequacy and social equity.

Crucially, where diversified systems raise productivity and improve livelihoods, they do so durably, performing particularly well under environmental stress and delivering production increases in the places where additional food is desperately needed. For example, the agro-ecological system of rise intensification approach is securing and increasing rice yields around the world, while “push-pull” systems – controlling pests by pushing them away with repellent plants or pulling them towards decoy crops – are doubling and trebling maize production in Africa.

The social change that so often accompanies this shift paves the way for revaluing local farming within new and often shorter supply chains, providing vulnerable populations with a viable alternative to the high and volatile production costs of industrial commodity agriculture and the uncertainties of global markets.

The picture is far from complete. To date these systems have seen only minimal investment and support. Either way, the burden of proof is on the proponents of industrial agriculture to show how it can ever be productive and sustainable, with or without miracle breakthroughs. In the meantime, a less dazzling but highly compelling agro-ecological alternative is taking shape and transforming food systems around the world. It deserves our urgent attention.

 Olivier De Schutter is the former UN special rapporteur on the right to food, and co-chair of iPES-FoodEmile Frison is the former director general of Bioversity International and the lead author of the first major report from iPES-Food

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