News

17 June 2015

A solution to combat climate change: an agriculture that stores carbon in the soil

2015 is the International Year of Soils which play a prominent role in our life by contributing to food security, climate change adaptation and mitigation and the provision of ecosystem services.

2015 is also the year of the Paris Climate Change Conference (Conference of the Parties to the United Nations Framework, Convention on Climate Change) which is scheduled to take place from November 30th to December 11th 2015 with the objective to achieve a global agreement on how to reduce green-house gaz emissions in order to keep the increase of the average temperature of the planet below 2 degrees.

The conjunction of these two events should be an opportunity to reconsider the way we manage our soils, and therefore the way we conduct agricultural production, in order to tap the full potential of soils and of agriculture in mitigating climate change.

For this, the report published in October 2014 by the Rodale Institute, a well known US non-profit organisation that has been supporting the research into organic farming, provides some interesting data and insights. Under the title ‘Regenerative Organic Agriculture and Climate Change A Down-to-Earth Solution to Global Warming’, the authors recall that ‘in 2012, total annual global emissions of greenhouse gases were approximately 52 GtCO2e’(Giga tonnes of CO2 equivalent). These emissions should ‘soon drop to a net of 41 GtCO2e if we are to have a feasible chance of limiting warming to 1.5°C’.

The report continues by stressing that there are two ways in which this reduction can be achieved: by reducing emissions and by increasing carbon sequestration. According to ‘recent data from farming systems and pasture trials around the globe […] we could sequester more than 100% of current annual CO2 emissions with a switch to widely available and inexpensive organic management practices’.

These practices, termed as ‘regenerative organic agriculture’ would however require to change fundamentally the way agriculture operates today and which makes it one of the main sources of greenhouse gaz emissions, a need that has repeatedly been emphasized on www.hungerexplained.org, as it would also contribute to provide new opportunities for hundreds of millions of undernourished to exit from the hunger and poverty trap. [read]

So-called ‘modern’ conventional agriculture ‘is a net producer of greenhouse gas emissions both directly through conventional farming practices that deplete soil carbon stocks while emitting nitrous oxide (N2O), and indirectly through land-use change’(e.g. deforestation). As a result, farming has made it that ‘most agricultural soils have lost from 30% to 75% of their original soil organic carbon’. But it is known that the lesser there is carbon in soils, the less they are biologically active and are able to store water, making them more vulnerable to drought.

But what is ‘regenerative organic agriculture’? It is ‘marked by tendencies towards closed nutrient loops, greater diversity in the biological community, fewer annuals and more perennials, and greater reliance on internal rather than external resources’. The document lists several well-known practices that fit within this type of agriculture such as conservation tillage, cover crops, enhanced crop rotations, residue retention and composting. The report also provides several examples of systems applied in specific locations and produces estimates of their carbon sequestration effect. By extrapolating these data, the report states that ‘even if only half of all available cropland shifted to regenerative agriculture and no changes are made in pasture management, we would meet the 2020 threshold of 41 GtCO2e that makes many scenarios for limiting warming to 1.5°C feasible’.

Much of what the report says is not really new, but its value added is to put the development of regenerative organic agriculture in the context of the combat against climate change. It also addresses, although probably too rapidly, the issue of yields which is often put forward by the supporters of conventional agriculture in order to explain that there is no alternative to it and to turn down any attempt to replace it by a more sustainable agriculture. On hungerexplained.org, we have already argued that replacing conventional agriculture by organic agriculture (particularly when it regenerates the soil) would actually increase world agricultural production, create more jobs in the sector and improve the well-being of those very farmers who suffer from undernourishment today.

More research is definitely required to move in the direction indicated by the Rodale Institute report and it can yield rapid results in the combat against climate change and hunger. This more than justifies that the topic should be discussed at the forthcoming Paris Climate Change Conference and for the decision to be taken to allocate appropriate resources to further research on and promotion of the practices that are part of regenerative organic agriculture.

However, it must be said here that there will be a limit to the quantity of carbon that soil will be able to store, and, once the transition period to a new agriculture will have occurred and that the maximum level of storage of carbon in the soil will be reached, other solutions to store carbon will have to be found.

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