There are now four countries suffering from, or are still under the risk of, famines: Nigeria, Somalia, South Sudan and Yemen. While in our Platform of Survival, climate and agriculture are mentioned most, those countries are all experiencing conflicts. Indeed, most of today’s declared famines are the result of war and are used as weapons against a country or a region, turning the victims into hostages of hunger. However, many food insecurities are also affected by climate and could be changed by using different methods of agriculture.

According to a report published by Oxfam, famine is caused by “multiple factors, compounded by poor (or even intentionally bad) policy decisions that make people vulnerable. When no one addresses this vulnerability, it leads to famine.” Let’s take a close look at the four countries to understand some of the factors that are beyond climate and drought.

In Nigeria, the conflicts between armed groups, mostly Boko Haram and Nigerian military, prevent farmers from growing food. According to a number of reports, farmers were unable to grow any food in some northeastern areas for almost five years. Boko Haram controlled northeastern areas, which made it challenging to get humanitarian aid to the people suffering. While the UN declared that famine had been “averted” in 2017, millions of people are still at risk, for armed attacks and conflicts continue to exist.

In South Sudan, famine is caused by civil war. Since the conflict started in 2013, more than four million people have fled their homes. According to 2019 report by Human Rights Watch, seven million people are in need of humanitarian assistance, most of them face acute food shortages. Again, the armed conflict means people are cut off from food supplies. All parties have attacked aid workers and restricted access to populations in need. At least 12 aid workers were killed in 2018, bringing the toll to over 100 since December 2013.

Unrest, war, and armed conflicts are the cause of the famine in Yemen. The war began when Saudi Arabia formed a military coalition and began airstrikes in 2015. While all parties, including the rebels, are responsible for casualties, the Saudi-led coalition is responsible for most attacks targeting hospitals, schools, and humanitarian organizations supplying food and medicine. The armed conflict continues. According to a UN World Food Programme report, published on March 2019, twenty million Yeminis (70 percent of the population), are food insecure. This marks a 13 percent increase from 2019. Yemen is now described as “the world’s worst crisis.”

In Somalia, a combination of conflicts and drought fueled the famine for 70 years. The conditions are not getting better. A report published by US on December 2018 warns that “many fear a repeat of the 2011 famine in which nearly 260,000 people died.” While the main cause is drought, this would not have happened without the conflicts that control access to food and medicine— scarcity is climate- and human-led by wars.

The UN Development Programme supported sand dams. For instance, sand dams in Puntland, Somalia, can harvest water above and below ground and help to build the resilience of local people. However, efforts to combat climate factors and drought have to be combined with measures to stop and prevent armed conflicts.

In summary, taking a look at all countries at the risk of or declared under famine, there are multiple factors and no one solution to help end this. For instance, drought is a factor that could be dealt with scientifically while raising resiliency in communities. But when dealing with armed conflicts and intentional causes of famine, there are many measures that need to be taken globally. For instance, the famine in Yemen could have been prevented if the conflict ended and arms sales seized. Famine could have been prevented if food and medical aid had found their way to the people of Yemen.

The human population may reach a maximum size of around eleven billion by the end of this century. Already we number 7.3 billion, and therefore we must prepare for about a 65 percent increase in food production. Is this possible? Probably so, though many things — most obviously the climate — can interfere. There is already far more food per capita available on the planet today than would be needed if it were divided equally among the whole human population. Production has kept ahead of population growth and can continue doing so; that is not the main problem.

But while some populations consume more than their fair share of the world’s food (indeed, more than is good for them) there are billions who consume too little already. About thirty percent of all food is wasted — thrown away without being consumed. The poor have too little food, and what they eat usually is not the optimum combination of proteins, carbohydrates, and fats.

Most people now buy their food instead of producing it themselves, so their intake is affected greatly by the price. Yet lately the price of food is not determined by the relationship between supply and demand, as ordinary economic theory would predict. It has been much more affected by the world price of oil! The production and distribution of food depends largely on machinery and chemicals, which in turn are affected by the price of oil.

There is also the growing influence of the climate. Global warming is not the cause of famine, as we shall see below, but it is increasingly determining overall food production. When Russia’s wheat crop failed a few years ago, the country stopped all its exports of grain for the year, which greatly increased the world price of food and led to civil unrest in many countries, most notably in the Middle East, where most food is imported. The Arab Spring was one outcome. Global politics is a stronger factor in determining hunger now than the conventional factors: supply and demand.

Nevertheless, it is probable that sufficient food can be produced to feed the maximum human population that must be expected. However, there are four great challenges to be addressed:
1. How will we produce that food? Are the methods sustainable? (See plank 14.)
2. Who will get the food? Is the allocation of food equitable? Will some remain hungry while other food is wasted?
3. What kind of food will be produced and distributed? How must our dietary habits change?
4. How will we allocate the energy necessary to produce the food and how will we distribute it equitably and without waste?

All of these questions are addressed to some extent by other planks in the Platform. The remainder of this article, however, will address a very specific type of food deprivation event: famine.

Definition of Famine

Like most complex social phenomena, definitions (and related causes and solutions) of famine are contested. Moreover, many cases diagnosed as ‘famine’ do not meet textbook definitions, which are often subjective, used loosely, and/or not be transferable from one community to the next (de Waal, 2000). One useful definition breaks famine down into its constituent parts:

1. Hunger including subjective feelings of severe and prolonged hunger, going without acceptable food and the measurable fact of undernutrition.
2. Impoverishment including the loss of livelihood, income and assets and other components of increased poverty.
3. Social breakdown including distress migration, family and community breakdown.
4. Mortality rates are increased and usually concentrated among vulnerable groups such as children, women, migrants, etc.
5. Social and economic responses/resistance of individuals, families and groups to each of the above (de Waal, 2000).

Famine, it must be noted, can occur without all of these components being present.

Classification Systems

A number of different classification systems used to determine when a famine is present. One of the most widely used has been developed by the Integrated Food Security Phase Classification (IPC) (1) According to the IPC, the international standard for classifying food insecurity and malnutrition, a famine can be declared only when certain measures of mortality, malnutrition and hunger are met. These measures are:

• at least 20 per cent of households in an area face a complete lack of food and/or other basic needs
• acute malnutrition rates exceed 30 per cent, and
• the mortality rate exceeds two persons/day/10,000 persons.

According to this definition, areas are declared to be in famine only when substantial deaths have occurred due to lack of food consumption on its own or by its interaction with disease. By classifying famine as “situations where mass deaths have already taken place due to starvation, the IPC Famine area classification is only applied to a situation that is the outcome of a sequential and causal series of events between severe food deficits, acute malnutrition and the final expression of deaths” (IPC, 2016, p. 2).

Other definitions of famine challenge the idea that famine is a discrete event triggered by food shortage resulting in mass deaths by starvation. For example, Devereux (2000) notes that mass starvation and deaths is only one possible outcome of famine and that we need to consider other outcomes such as fertility decline, economic destitution, community breakdown, distress migration and exposure to new diseases. Thus, famines could be declared even without widespread deaths, allowing situations where extreme food gaps, displacement, and total collapse of livelihoods and high acute malnutrition to be considered famine.

Different Types of Famines

While the above would suggest that famine is a category on its own and can only be declared when particular criteria are met, others have proposed different categories/types of famine.

a) Time

Famines last different amounts of time. The Somalia famine in 2011–12 and the Dutch Hongerwinter famine of 1944–45 only lasted a few months. In the cases of Ireland in the late 1840s, and China in 1959–61, famines lasted a few years.

b) Severity

Famines can be distinguished according to the degree of severity, which is usually measured by the number of deaths. Devereux (2000) distinguishes between ‘great famines’ (100,000 or more excess deaths) and ‘catastrophic famines’ (one million or more excess deaths. De Waal (2000) identifies three degrees of famine severity:

1. Famines involving primarily hunger and impoverishment
2. Famines in which there are elevated rates of mortality
3. Famines in which there are spectacularly high death rates alongside severe social dislocation and collapse (p. 7)

Causes of Famine

Given the contested and complex nature of famine, as well as different types of famine, there are different explanations for what causes famine. Some of these are outlined in the chart above and some outlined in this section here.

a) Famine and democracy

The conventional explanation to explain the cause of famines was the food availability decline hypothesis. The assumption was that the central cause of all famines was a decline in the supply of food. In contrast to this argument, economist and philosopher Amartya Sen (1981, 1983) claims that a lack of democracy and famines are interrelated. Sen argues that no substantial famine has ever occurred in any independent and democratic country. In his book, Poverty and Famine, Sen uses the example of the 1944 Bengal famine to show that it occurred due to a lack of democracy in India under British rule aggravated by the colonial government’s suspension of trade in rice and grains among various Indian provinces. More recently, Ó Gráda (2015) has shown that the primary cause of the Bengal famine was the unwillingness of colonial rulers to divert food from their war effort.

According to Sen, entitlements are the set of alternative commodity bundles that a person can command in a society using the totality of rights and opportunities that s/he faces. Famine occurs when food entitlements decline (FED). In Poverty and Famines, Sen connects famine to people’s lack of entitlements rather than to, for instance, food shortages or ecological disasters. For example, when market incomes fall in relation to the price of subsistence foods, food becomes not physically unavailable, but unaffordable.

Others have critiqued the assertion that famines cannot occur in democratic states. For example, De Waal (2000) points out some of the limitations of Sen’s hypothesis that there can be no famine in democracies noting that the reality is much more complex. He notes the following examples where famines have occurred in democratic states where liberal institutions failed to prevent the famine:

1. Ireland (1845-9)
2. Bihar, India (1966-67)
3. Bangladesh (1974)
4. Sudan (1986-88)

De Waal (2000) explains that while civil rights and free speech under democracies have the potential to contribute to social and economic rights, including the right to food, history has shown us that the “gross abuses of social, economic and cultural rights can exist in democracies”

b) State-sponsored famines

Famine has also occurred due to government policies. Here are two examples:

i) The Chinese Great Leap Famine (1959–61). In 1958, Mao Zedong’s Communist Government launched the Great Leap Forward campaign, aimed at rapidly industrializing the country. The government forcibly took control of agriculture. Barely enough grain was left for the peasants, and starvation occurred in many rural areas. Exportation of grain continued despite the famine and the government attempted to conceal it. While the famine is attributed to unintended consequences, it is believed that the government refused to acknowledge the problem, thereby further contributing to the deaths. In many instances, peasants were persecuted. Between 20 and 45 million people perished in this famine, making it one the greatest modern famine ever in terms of lives lost (Thaxton, 2008).

ii) The Holodomor – Soviet famine (1932–1933). In 1932, under the rule of the USSR, Ukraine experienced one of its largest famines. Between 2.4 and 7.5 million peasants died as a result of a state sponsored famine. It was termed the Holodomor as it was a deliberate campaign of repression designed to eliminate resistance to the government’s forced collectivization of agriculture. Forced grain quotas imposed upon the rural peasants and a brutal reign of terror contributed to the widespread famine. The Soviet government continued to deny the problem and it did not provide aid to the victims nor did it accept foreign aid (Tauger, 2001).

c) Famine and war

War and famine, two fearsome horsemen, have long ridden side by side. Armed conflict disrupts food systems, destroys livelihoods, displaces people, and leaves those who do not flee both terrified and unsure when they will eat their next meal (de Waal, 2015, p. 23).

Nearly half of all famines between 1870-2010 occurred during active armed conflict. Over one-quarter of all famines took place during conditions of active political repression, and 3.28% of famines occurred in countries emerging from conflict. Only one-fifth of famines occurred in countries with no conflict or political repression (World Peace Foundation, 2015).

d) Famine and climate change

Global climate change has challenged the Earth’s ability to produce food, causing food production fluctuations and shortfalls, potentially leading to famine (Physicians for Social Responsibility, 2013). We see this currently in Somalia where climate change has played a significant role in famine there. [De Waal 2018 takes issue with the contention that global warming currently causes famine]

OTHER TOPICS:

Famine and epidemic disease

When there is a severe lack of food many people will die of starvation, but between starvation and death there is nearly always disease. When people don’t have enough food to eat, acute malnutrition sets in and weakens the immune system (World Health Organization, 2018).

Disease cannot be said to cause famine, but it is often linked to famine given victims’ increased susceptibility to disease. The Irish famine (1845-1850) is a case in point where general starvation and disease were responsible for more than 1,000,000 excess deaths, most of them attributable to fever, dysentery and smallpox (Woodham-Smith, 1962).

Where and when has famine occurred?

Geography of famine

Almost every inhabited continent in the world has experienced a period of famine throughout its history. The geography of modern famine is overwhelmingly a story of Asia and eastern Europe, which account for 87% of famine deaths in the period. Approximately half of these (56.5 million) were in East and South-east Asia. South Asia accounted for 16.5 million deaths. Europe including the USSR accounted for 18.17 million famine related deaths. African famine deaths during the entire period are estimated at 9% of the total ( 9.575 million deaths), with the majority occurring in the late nineteenth century in Congo and north-east Africa. Latin America counted about 1.5 million famine deaths, all in Brazil in the nineteenth century. The Middle East has an estimated 2.07 million deaths, most associated with World War One and the Armenian genocide (World Peace Foundation, 2015).

History of Famine

The history of great famines can be classified into 4 broad periods:

1. famines of European colonialism (until about 1914);
2. extended period of the world wars and accompanying mass starvation (1914 – 1950);
3. famines caused by totalitarianism, and
4. decline and smaller famines and humanitarian crises since the 1970’s (World Peace Foundation, 2015).

Since 1870, famine and episodes of forcible mass starvation have killed 104.3 million people. The main trend, however, is downwards. In each decade between the 1870s and the 1970s, great famines (those that kill more than 100,000 people) killed between 1.45 million and 16.64 million, at an average of about 927,810 per year. Since 1980, the annual death toll in great famines has averaged 75,217, or about 8 per cent of the historic level (World Peace Foundation, 2015).

Famine in the 21^st Century

In terms of recent history “famines in peacetime are no longer the looming threat they have been throughout history. “In peacetime” is the crucial qualifier. The globalization of disaster relief and increasing global food output are responsible for this (Ó Gráda, 2015,p. 8).

In the 21^st century, calamitous famines—those causing more than 1 million deaths— have been eliminated. Until recently, great famines have been more common. Deaths from these famines exceeded 15 million in five separate decades in the 20th century. In the 21st century, the death toll from great famines is near 600,000, still cause for concern, although relatively low by historical standards (von Grebmer et al, 2015, p. 5). There are a few exceptions, such as Somalia in 2011–12. Nowadays the closest countries outside parts of sub-Saharan Africa come to famine is what the Food and Agricultural Organization dubs “severe localized food insecurity,” and that hardly ever culminates in famine (Ó Gráda, 2015).

Ethiopia (1983-85)- experienced multiple, simultaneous civil wars between 1974 and 1991, along with severe famines during this period, including the worst famine in current history between 1983 and 1985 (Africa Watch 1991; von Braun & Olofinbiyi 2007).

South Sudan The famine in South Sudan is ‘man-made’, and here we see a clear link between famine and lack of democracy. South Sudan became an independent nation in 2011, and since then it has been plagued by civil war. All involved in the conflict are parties to the famine. A localized famine was declared for Leer and Mayendit [counties] on 20 February 2017, an area where violence and insecurity have compromised humanitarian access for years. More than one million children are estimated to be acutely malnourished across the country; including 270,000 children who face the imminent risk of death should they not be reached in time with assistance (O’Brien, 2017).

Yemen The current famine in Yemen has been caused by the Saudi-Arabian led intervention in Yemen and the blockage imposed by Saudi Arabia and its allies. According to an October 2018 article by the United Nations, around 14 million people or half of the population of Yemen is at risk of famine. At the end of 2017, 130 children were dying every day from extreme hunger and disease (United Nations, 2018a)

Famine Response and Prevention

Political Solutions

Given the political nature of famine, as outlined above, political institutions can and have played a role in preventing famine. Sen (1981) has shown how liberal institutions in India, including competitive elections and a free press, have played a major role in preventing famine there since independence.

Anti-famine political contract (de Waal, 2000)

The theory of the ‘political contract’ focuses on the contract between rulers and people that ensures famine prevention. Effective political action against famine requires more than just democracy, but the active mobilization of people (e.g. through the US civil rights movement) and specialist institutions to promote human rights (e.g. Human Rights Watch). Famine must be made an issue of political concern even when there is no famine. Complex interventions need to take place in advance to prevent famines. Coalition-building is essential to creating anti-famine politics, especially in terms of fighting famine with other goals. Mobilization against famine therefore has a set of interconnected goals and these are what de Waal (2000) calls a ‘political contract’ against famine:

1. To ensure a timely response to the threat of famine.
2. To help create effective anti-famine mechanisms
3. To educate the public
4. To ensure that all citizens and residents are entitled to protection against famine.
5. To enforce accountability

Criminalizing starvation

De Waal (2018) in his recent book entitled Mass Starvation has called for the criminalization of starvation. Starvation should be designated a crime and prohibited worldwide. While there are already enough international laws to prohibit and prosecute action leading to famine, those same laws do not explicitly name starvation and famine as crimes. This is why de Waal (2018) used the term ‘famine crimes’ and calls for activists around the world to take up the cause of criminalizing starvation.

United Nations Development Program: Sustainable Development Goals [related to hunger, food security and famine]

The Sustainable Development Goals (SDGs) signal a renewed commitment to end hunger and global poverty by 2030. While Goal 2: Zero Hunger most explicitly addresses issues concerning famine, other relevant goals to be met by 2030 that are required to prevent famine are listed here. Particular attention is drawn to goal 16 given the above-noted political responses that are required to prevent famine (United Nations Development Program, 2018).

Goal 1: No poverty

To end poverty in all forms and dimensions.

This involves targeting the most vulnerable, increasing access to basic resources and services, and supporting communities affected by conflict and climate-related disasters.

Goal 2: Zero Hunger

To end all forms of hunger and malnutrition, making sure all people have access to sufficient and nutritious food all year round.

“This involves promoting sustainable agricultural practices: supporting small scale farmers and allowing equal access to land, technology and markets. It also requires international cooperation to ensure investment in infrastructure and technology to improve agricultural productivity.”

Goal 3: Good health and well-being

To end the epidemics of AIDS, tuberculosis, malaria and other communicable diseases.

Goal 6: Clean Water and Sanitation

To ensure universal access to safe and affordable drinking water for all.

Goal 14: Life Below Water

To sustainably manage and protect marine and coastal ecosystems from pollution, and address the impacts of ocean acidification.

Goal 15: Life on Land

To conserve and restore the use of terrestrial ecosystems such as forests, wetlands, drylands and mountains.

Goal 16: Peace, justice and strong institutions

To significantly reduce all forms of violence, and work with governments and communities to find lasting solutions to conflict and insecurity.

More needs to be done to help people become more resilient and help them better withstand the consequences of armed conflict. “If the SDGs are to be more than aspirations, we need to find real and lasting solutions to conflict, tackle growing inequalities within and across borders, mitigate the effects of climate change, and eliminate the food insecurity that is most profoundly affecting the poorest places on the planet” (von Grebmer, et al., 2015, p. 3).

References for this article can be seen at the Footnotes 3 page on this website (link will open in a new page).

There is the potential to store much more carbon in soils, drawing it down from the atmosphere. A recent estimate based on a model of soil organic carbon sequestration suggested 3.5 Gigatonnes of carbon dioxide a year(1) could be sequestered in the soil. (A Gigatonne [Gt] is 1 billion tonnes.) Total global anthropogenic emissions are 37 Gigatonnes of carbon dioxide equivalent a year.

Resilient food production. Resilience refers to the ability of a system to ‘bounce back’ after a stress on the system, to resume its former function. In the present context, we might consider the likely stressors to be war and climate change. War may bring soil compaction, burning and toxic pollutants to soil. Climate change will bring storms, flooding, drought, wildfire and may bring economic and social collapse. A resilient food system would be able to continue production through such shocks, resume production soon after a time-limited shock, and adapt to changing factors affecting food production, such as climate and sea level rise. Its goal would be food security for all.

Food security as defined by the United Nations’ Committee on World Food Security, is the condition in which all people, at all times, have physical, social and economic access to sufficient safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life. Food production will need to increase dramatically to provide for projected population levels mid-century. Fertile soils with ideal levels of soil organic carbon are needed to accomplish that.

It is worth noting that currently, the leading cause of global hunger, according to the United Nations Food and Agriculture Organization (FAO) has become climate change, with its attendant extreme weather events, land degradation, desertification, water scarcity and rising sea levels.(2) This cause leads violent conflict and economic depression as longstanding causes of malnutrition.

Soil carbon sequestration is any process that brings carbon from the atmosphere (in the form of greenhouse gas carbon dioxide) to increase the amount of carbon held in the soil. This includes all stages of decomposition of organic matter on the way to becoming stable humus, insoluble carbonates as a result of rock weathering, or charcoal.

The problems

1. Soil health status

The UN Food and Agriculture Organization (FAO) in a 2015 document, The Status of the World’s Soil Resources, says ‘the majority of the world’s soil resources are in only fair, poor or very poor condition. Today, 33 percent of land is moderately to highly degraded due to the erosion, salinization, compaction, acidification and chemical pollution of soils. Further loss of productive soils would severely damage food production and food security, amplify food-price volatility, and potentially plunge millions of people into hunger and poverty.’

FAO has produced a remarkable map showing the levels of soil organic carbon in all terrestrial areas.(3) It has been estimated that soil has lost over 50% of its former carbon content, both by natural and human processes.(4)

We need to consider two processes — physical soil loss and qualitative soil degradation.

Soil loss

Without the presence of humans, there is a continual process of soil formation and soil loss. Soil is formed by the physical weathering of the rocks that form the Earth’s geosphere, as they crumble on the surface into tiny pieces under the influence of wind and water. This occurs at the rate of about a centimetre every few hundred years. The wind and water also cause the loss of soil as it then gets swept away by water and transferred to the sea or blown away by winds to the sea or a different land location. Vegetation coverage of land halts or slows this process.

Humans have immensely accelerated the process of soil loss, especially by changing the use of the land to agricultural and pastoral uses. Use of the land that involves stripping it bare of vegetation and ploughing it to expose its below-surface structure to oxygen, sun, wind and water greatly speeds soil loss, particularly on sloping land.

A thousand years ago, humans used relatively little of the Earth’s land. Pasture and cropland occupied 1-2% of the Earth’s ice-free surface. Now in most countries almost all the land with suitable soils and climate is changed for human use. This has entailed large physical losses of soil. Other losses are incurred by urbanization. Human settlements were built where people could derive a living from agriculture on fertile land. As settlements grew, more and more of the fertile land was taken for buildings, roads and other infrastructure. Now that more than half of humanity lives in urban settings, the amount of land covered and removed from natural processes has become significant. Furthermore, modern cities cover the land with impermeable substances like cement and asphalt, called ‘soil-sealing’. Life in the soil beneath these surfaces has been extinguished permanently.

Climate change is causing more soil loss. More violent winds and rainstorms increase losses. Sea level rise from climate change is inexorably erasing coastlines, and salinizing fertile coastal plains. These physical losses are occurring at the same time the human population is rising and requiring more food production.

Loss of soil life

These processes also contribute to the loss of the vibrant web of soil life. The most important of these is changing the use of land from natural forest or grassland to cropland.(5)

This results in losses of 30-50% of soil organic carbon. Ploughing exposes soil carbon to oxidation and moisture loss and to further loss of soil life. It also disrupts the enormous and complex web of fungal roots (mycelia or mycorrhizae) that are part of mutual exchanges in supporting plant growth and the total soil food web. The use of inorganic fertilizers to add nitrogen, phosphorus and potassium to soil will indeed nourish the crop but tends to kill the soil life, as will herbicides and pesticides. Compaction of soil by heavy machinery and by poorly managed grazing will cause degradation of soil structure and soil life.

This loss of soil fertility is sometimes put into dramatic form by statements such as ‘We have only 60 harvests left before fertility gives out’. While it is hard to be so precise, the message is valid — soil, the basis for our lives and all other land species, is disappearing and degrading. Soil life is the basis of soil resilience. The complex community of living organisms in soil may be expected to slowly change as the climate changes. Such changes depend on an initial biodiversity. With speedier shocks to soil health, such as in flooding or drought, recovery of soil health also depends on the ability of a residual, diverse community to repopulate the soil.

2. Soil health and climate change

Loss of soil carbon contributes to climate change

Emissions due to land use change include those by deforestation, biomass burning, conversion of natural to agricultural ecosystems, drainage of wetlands and soil cultivation. The process of transfer of soil carbon to atmospheric carbon began 10,000 years ago as humans learned to clear and till the land for crops. This conversion of forest to cropland transfers 30-50% of soil carbon to the atmosphere. For most of human history, the gross quantities transferred were insignificant. For the last 150 years, the era of exponentially rising anthropogenic carbon emissions, those due to land use and changes of land cover made up 30% of the total emissions.(6)

It is also possible, but hard to measure, that some of the losses of soil carbon from water and wind erosion are deposited in bodies of water and thus sequestered from the atmosphere. However, with population growth, mechanization and then industrialization of agriculture the gross quantities have become a highly significant part of the climate crisis.

Soil emissions of nitrous oxide

Nitrous oxide is a long-lasting greenhouse gas around 300 times more potent in its greenhouse effect than carbon dioxide. It is emitted from agricultural soils to which inorganic nitrogen has been applied, and from pastoral soils from the urination spots of ruminants.

Soil methane

When biological matter decomposes in the presence of oxygen, carbon dioxide is formed. Without the presence of oxygen, methane is formed. Methane is a short-lived greenhouse gas, 34 times more potent than carbon dioxide in its first 100 years in the atmosphere(7), while it slowly converts to carbon dioxide.

Rice cultivation is responsible for between 9 and 19% of global methane emissions.(8) The flooded paddies lead to anaerobic decomposition of organic matter, producing methane.

Climate change affects soil health

As discussed above, extreme weather with flooding and high winds is likely to increase the loss of topsoil. Climate change induced drought will result in loss of soil moisture and therefore fertility.

We are accustomed to hearing about positive (vicious) feedback cycles in relation to climate change. There is one negative (benign) feedback cycle in relation to the impact of climate change on soil health. Higher levels of carbon dioxide in the air increase plant growth, absorbing more carbon. This in turn is assumed to lead to more root exudates, supporting more soil microlife, increasing fertility and sequestering more soil carbon. This relationship is speculative.

3. Food security and climate change

Food security depends on the availability of food, the ability of people to acquire it and use it, and the stability of this process over time. Here we will deal only with the availability of food from the land and the impact of climate change.

The relevant factors are increased average temperature, changes in rainfall and soil moisture, changes in weather variability, and extreme weather events.

In tropical areas, available human labour to tend the land will be affected. Labour output decreases with increasing temperature (9). This factor and diminishing productivity of some crops (10) affects not only food availability, but also access to food by the millions of people dependent on agricultural livelihoods.

Wild foods, especially important to those on the edge of food insecurity, are particularly vulnerable to changes in temperature and rainfall caused by climate change, and are predicted to markedly drop in availability.(11)

With the current level of commitments under the Paris Agreement, global temperatures may stabilize at an average of 3 degrees above preindustrial levels. At this level, productivity of all crops will be reduced. At a lower temperature increase, crops in temperate regions may be more productive, and those in tropical regions less so. Those most vulnerable to the impacts of climate change on food security are the populations already experiencing inadequate nutrition – usually in areas where both crop productivity and livelihoods are threatened. These are also the areas of highest population growth.

Solutions

We must reverse the human impact on soil loss and degradation (where it is reversible) and increase the capacity of soil to sequester carbon, while at the same time producing food to eventually support 10 billion people. Is this possible? It is quite unclear that this can be done. However we do understand the processes that will take us in this direction.

1. Stabilize population growth as soon as possible

The conversion of forest to cropland for food, fodder and fuel to accommodate the needs of an expanding human population is a major driver of climate change, Women in many countries lack access to reproductive health services. These are the very populations most vulnerable to climate impacts on food availability. Perhaps there could be a stream in the voluntary carbon offsetting system that flows to support reproductive health clinics as an emissions reducing (and soil health promoting) measure.

2. Make a phased transition to a circular economy oriented to equitable human well-being rather than to economic growth, and operating within Earth’s biophysical limits.

Land use change is partly driven by the impulsion toward economic growth, largely benefitting the already wealthy.

3. Cut deforestation, support afforestation

The carbon sequestration protection or gain is in both the wood biomass and in the soil carbon of the forest. This is particularly pertinent to tropical rainforest. Currently the Brazilian Amazon appears to be at great risk.

4. Reduce soil loss

• There is little likelihood of being able to prevent the loss of large areas of fertile land to sea level rise. It has been suggested that good topsoil might be removed from areas where loss from sea level rise is imminent and certain.
• Avoid soil disturbance on steep slopes. Where crops are planted on slopes, skillful terracing can minimize soil loss.
• The methods of conservation farming (see below) serve to prevent soil loss as well as to sequester carbon.(12)
• Agroforestry (see below) also prevents soil loss and sequesters carbon.

5. Increase soil carbon

The FAO speaks of significant ‘opportunities for soil carbon sequestration across all climatic zones and a wide range of cropping, grazing and forestry land use systems’.(13) They point out that increasing the carbon content of soils could reverse soil degradation and desertification, enhance productivity, increase water retention, increase the resilience of communities to climate change, especially drought, enhance biodiversity, reduce fossil fuel use in agriculture and reduce agricultural emissions of nitrous oxide, carbon dioxide and methane.

Accomplishing this entails major changes to agriculture systems, some of which are :

Organic farming

There is a large overlap between methods of soil carbon sequestration and of organic farming, which, in contrast to conventional farming does not use inorganic fertilizers, pesticides and herbicides. Conventional farming supplies crops with the essential nutrients (nitrogen, potassium and phosphorus), but not carbon, which plants derive from carbon dioxide in the air. Organic farming methods involve the use of compost and manure to supply these essential nutrients. Because these plant-based materials contain a lot of organic carbon, some of this will be turned into humus and sequestered.

Regenerative farming and Biological Farming

These more recent movements in agriculture demand whole systems thinking of the farmer, including soil health and biodiversity below and above ground. Both movements include the methods below.

Conservation tillage or ‘no-till’ methods

These methods leave undisturbed the structure of the soil with a slightly compacted protective upper layer. This protects the soil against the impact of wind, raindrops, light and oxygen. The undisturbed soil has better earthworm, fungal and microbial activity. It greatly reduces water runoff and therefore erosion by wind and water, and increases water retention. The latter may be the cause of increased resilience of no-till farming in situations of drought and high temperatures.(14)

In no-till methods, the carbon-rich humus is less exposed to the air. This reduces its oxidation and therefore its carbon dioxide emissions.

Mulching is the practice of covering bare soil to protect it against water run-off, wind, sunlight and heat, and to prevent weed growth. A great variety of materials may be used for this task, ranging from crop residues straw and bark to black plastic sheets. Clearly the purposes on which we are currently focussed strongly favour mulching materials that are high in carbon. These materials break down eventually, and some of their carbonaceous material goes to form humus, a relatively stable carbon store.

Cover crops. These are crops grown in between main crops for the purpose of maintaining the soil cover and producing crop residue to continue the mulch process.

Nutrient management. Carbon-rich materials supplying essential nutrients to plants will favour carbon sequestration. Compost and manure are a vital part of this cycle. To prevent nitrogen leakage into waterways, it is important to give the plants what they need in fertilization, and no more. The excess is likely to turn into inorganic compounds and to leach into waterways and emit nitrous oxide into the overburdened atmosphere.

Crop rotation and crop diversity encourages diversity of soil life.

Agroforestry is a collective name for land-use systems and technologies where woody perennials (trees, shrubs, palms, bamboos, etc.) are deliberately used on the same land-management units as agricultural crops and/or animals, in some form of spatial arrangement or temporal sequence. Soil carbon is enriched by the root mass of the trees or other woody perennials. (In addition of course, carbon is sequestered in the wood of the above-ground parts of trees.) Benefits of agroforestry according to FAO are:(15)

• Increased crop and livestock production and economic gain
• Increased soil moisture
• Soil conservation from wind erosion and improved soil quality
• Sequestration of atmospheric carbon
• Increased biodiversity by creating new habitat
• More humane conditions for animals (and farm labourers)
• Increased snow protection for crops
• Decreased heating costs when planted fairly close to a house.

Experimental methods of sequestering carbon in cropland are:

Enhanced weathering.(16) The slow natural process of chemical weathering of rocks incorporating silicates, eg basalt, involves extraction of carbon dioxide from the air. The resulting compounds alkalinize the soil and eventually run to the sea, countering ocean acidity. There is experimental work on mechanical pulverization of basalt, which is then spread on cropland fields. The hope is that the resulting reactions, enhanced by a great increase of surface area of exposed rock dust, will increase plant growth, counter ocean acidity and sequester carbon. All this remains to be demonstrated. The process is energy intensive and fairly costly.

Biochar application. Charcoal produced by anaerobic combustion of biomass provides habitat for soil life, and increased water retention. It is a particularly long lived form of sequestration. No-tillage subsurface application of biochar-water slurries minimizes disruption of soil root zone microlife and allows earthworms to slowly mix biochar into topsoils.(17)

Management of pastures and rangeland

About a third of global terrestrial carbon is stored in grasslands. Most of this is underground, in the soil life, grassroots and mycorrhizae. Most grasslands are subject to some form of human management. Historically it appears that grassland soil has lost a large proportion of its carbon to the atmosphere, especially during conversion of grassland to cultivation of crops. A meta-analysis of such conversions showed a loss of 59% of soil carbon.(18)

Remaining grassland is mainly used for grazing large herbivores for human use. This land is subject to erosion by wind and water and to overgrazing. There is potential to store more carbon in this ‘sink’, drawing down from atmospheric carbon. This can be done by:(19) (20)

• Fertilization
• Irrigation
• Sowing legumes or improved grasses
• Management of the numbers of animals per hectare
• Agroforestry, especially shelter belts to protect from erosion
• Enclosure of degraded areas from livestock
• Managed grazing(21) This is an important and growing pastoral practice. Herbivores are rotated through pasture paddocks on a schedule that allows regeneration of above and below-ground parts of the grassplants. At the time of grazing of the grass blades, much of the root mass is shed, enriching the soil with decomposing carbon compounds which will eventually form humus. This cycle repeats with every grazing rotation.

Other experimental initiatives to increase grassland soil carbon are:

• Regenerating the circumpolar steppes toward its former grassland-herbivore system.(22) This is a return to the natural model of interval grazing as described above. A very large-scale experiment is proceeding on the Siberian steppes where dangerous permafrost thawing has begun. By the reintroduction of herbivores it is intended that northern boreal forest will be converted back to grasslands. When snow-covered, this will increase the reflectivity of the area. Where herbivores scrape away snow to feed on frozen grass, they remove the insulation of snow on the permafrost, and its temperature decreases, preventing thawing. The potential impact of this experiment, if successful, is huge.
• The introduction of biochar. This has the important advantage of decreasing nitrous oxide emissions(23), but is currently seen as too costly for use at this scale.
• Pasture cropping.(24) Annual crops are seed-drilled into perennial pasture when domestic animals have been rotated out of these fields. After the harvest, the fields are again grazed. No-till, biological methods are used. Soil carbon rises.

6. Reduce emissions of soil nitrous oxide and methane

Nitrous oxide. Reduce use of inorganic nitrogen fertilizer. Apply nitrogen fertilizer with precision in timing and application to achieve maximum uptake by plant, with little left for emissions or leaching. Reduction of cattle herd numbers will also reduce this source of a potent greenhouse gas.

Soil Methane. New ways of managing rice production will result in less methane emissions from this source. Avoid draining wetlands and peatlands.

Impact of these measures on greenhouse gas emissions and on food productivity

Scientists associated with the Drawdown Project(25) have done calculations for some of the measures above, estimating the extent of possible adoption of each measure between 2020 and 2050, and calculating the carbon dioxide equivalent of saved emissions. The current global emission level is about 37 Gt a year. If all the soil carbon improving measures listed in the Drawdown list of 100 (largely corresponding to the lists above) are added together, they total about 150 Gt saved over 30 years, or 5 per year. While this is a very rough calculation, it serves to show that the impact of soil health improving measures on climate change is a substantial one.

The impact on food productivity is not calculable, but in each case it would be expected to be positive.

Impact of these measures on biodiversity

For each measure the biodiversity of the soil is protected or improved. This is very important. The ecosystems under our feet are unseen, highly complex, and our lives depend on them. Those strategies that involve ceasing the use of herbicides, pesticides and fungicides also protect above-ground diversity, particularly of insects, some of which are pollinators. Some measures, eg forest protection, reafforestation and agroforestry, protect or increase habitat for a myriad creatures — insects, birds, reptiles and mammals.

Problems with the solutions

Nitrogen leaching

Application of organic materials (compost, mulch) to enrich soil carbon will also increase levels of organic nitrogen. This is an essential nutrient for plants, and higher levels may increase food production. However, if nitrogen inputs are higher than can be absorbed into plant growth, they may convert into inorganic soluble forms of nitrogen and leach into waterways.(26) (27) Higher levels of soil carbon mitigate this effect. This is also a significant problem in the use of inorganic nitrogen fertilizer when applied in excess of plant needs. Nitrogen leaching is a serious pollutant of waterways, and thus an important factor in loss of biodiversity of freshwater systems and ocean ecosystems.

Albedo effects of biochar

Charcoal applied to the upper layer of topsoil darkens the earth. This may be used to advantage to warm the soil and enhance plant growth. New Zealand Maori applied this technology to their kumara gardens. However, over large areas, this would decrease the reflectivity of the Earth’s surface and increase at least local warming. This is an example of what is known as the ‘albedo effect’.

Limits of sequestration

There are limits to how much carbon a soil can hold in relatively inactive form. We may be able to sequester at a high rate for 30-50 years(28) before this carbon sink is satiated. That carbon will remain sequestered only while restorative farming practices continue.

Who is working on this?

4 per 1000. The ‘4 per mille Soils for Food Security and Climate’ was launched at the COP21 in Paris in 2015 with an aspiration to increase global soil organic matter stocks by 4 per 1000 (or 0.4 %) per year to sequester carbon.(29)

World Soil Charter. A new World Soil Charter(30) was adopted by the members of the UN Food and Agriculture Organisation in 2015. It states that

The overarching goal for all parties is to ensure that soils are managed sustainably and that degraded soils are rehabilitated or restored.

Good soil governance requires that actions at all levels — from States, and, to the extent that they are able, other public authorities, international organizations, individuals, groups, and corporations – be informed by the principles of sustainable soil management and contribute to the achievement of a land-degradation neutral world in the context of sustainable development.

The adoption of the World Soil Charter and the 4 per 1000 target would be a useful basis for action in developing supporting policy.

The UK government is in the process of introducing an agriculture bill that pays attention to soil health and incentivizes farmers to do so. It sets a goal of restoring all degraded soils by 2030.(31)

What can the ordinary citizen do?

For climate change the data is clear. We need policies that will protect soils from loss, degradation, sealing, physical disruption, and unskillful nitrogen application. We have global statements. We know the strategies. We need citizens who understand the need and push policies at all levels. We need urbanites who understand the enormous importance of soil health and who will demand policies that enhance it.
External Link
For food production, the situation looks difficult and involves tough choices between the soil ecosystem service of biomass production and all the other soil ecosystem services, eg water provision, biodiversity habitat. In biomass production, we need to choose between biofuel, with little return of residues to the soil, and food. With food production, we need to choose between meat and dairy and food crops. Do we have enough land to support population sizes ahead? This is not clear. We must avoid further conversion of natural ecosystems to food production. We probably need to convert biofuel production areas and animal fodder production to human food production. Biofuel to food conversion would gain soil carbon because of crop residue return. Animals could still be raised as totally pasture-fed on land unsuitable for crops or by silvopasture methods on partially forested land. We must avoid any further deforestation and we need to increase forest area.

The ordinary citizen can ensure that their diet is consistent with maintenance of good health, with minimal carbon emissions, and from food systems that are sustainable. This means a plant-based diet with no or small amounts of meat and dairy foods. The EAT-Lancet commission on healthy diets from sustainable food calls this The Great Food Transformation, and asserts that it is an essential component of mitigation of climate breakdown.(32)

At a household level, anyone can compost organic waste. In household gardens, the practices of no-till, compost application, mulching, crop rotation and high diversity will benefit soil carbon content and also productivity.

Farmers need incentives to change practices. Observation of increased yields with some practices may be sufficient. However it would be helpful to be able to incentivize farmers for increasing their soil levels of organic carbon. For this, reliable measurement is necessary, and this has been a problem. However satellite and drone-based technologies are emerging and this may facilitate incentivizing strategies.(33)

Conclusion

Soil conservation and soil carbon sequestration are methods of mitigation of climate crisis that can be instituted rapidly and produce results beginning within a year. Many elements of implementation are low cost . They work with natural processes. They are decentralized and can be done at any scale. They have the valuable benefit of enhancing food production. These merits contrast markedly with other methods of carbon sequestration such as carbon capture and storage. They should feature far more prominently in policy development at all levels.

Bibliography

FAO Soils Portal. http://www.fao.org/soils-portal/soil-management/soil-carbon-sequestration/en/

Acknowledgements

Thanks to Adrian Myers, farmer and scholar, Don Graves, Katerina Seligman and Jack Santa Barbara for helpful comments on the manuscript.

References for this article can be seen at the Footnotes 3 page on this website (link will open in a new page).