Johan Rockström, executive director of the Stockholm Resilience Center (a global leader in governance for resilience in social and environmental systems), recently visited the foundation to talk about some of his latest work on agriculture and environmental change. After his talk, I got the chance to sit down with Johan and ask a few questions.

KS: You are about to release your new book The Human Quest: Prospering within Planetary Boundaries at Rio+20. In a few words, what are the most critical boundaries for agriculture and food production, and how are we doing?

JR: First let me say this. We’re at the ceiling of what the planet can cope with, so business as usual – for agriculture as much as any other sector – is a dead strategy.

Ecosystems, such as a forest or an agricultural system, have multiple stable states. But they may tip from one state into another if they are put under increasing pressure, such as by processes that over-exploit resources or change the basic functions of the system. The new state may not provide the same kind of services and benefits to people as the old one, in which case they will be considered deteriorate. For example, extreme nitrogen and phosphorus pollution from fertilizer run-off can actually lead to a lake becoming ‘dead’. For the majority of the Earth’s ecosystems we don’t know where the specific tipping points are, and as we move them closer to their limits, the chances increase that something will tip the system into a deteriorated state.

Since the last ice age (about 12,000 years ago) the planet has been in the Holocene era. The Holocene era is marked by extraordinarily stable temperatures, making it ideal for human life – it also allowed for humans to invent agriculture. We know this era well, and we know that we need to stay in Holocene-like conditions to sustain the quality of human lives and environmental resources. These criteria provide us with a framework to identify the boundaries within which humans and the environment are in a safe operating space and the particular environmental factors we must steward carefully to avoid tipping the whole planet, and not just specific ecosystems, into an undesirable state.

KS: So then what do you see as the way forward for agriculture?

JR: Agriculture has the unique characteristic that with a few shifts, it can make a quick transformation from being part of the problem to becoming critical to the solution. As one of the major drivers of environmental change, agriculture is in the position to become one of the major avenues through which we better manage our natural resource base. Sustainable intensification – producing more food for every unit of land without degrading the natural resource base – is really the only option. If agriculture expands any further, we risk losing even more of the planet’s capacity to capture and store greenhouse gases or conserve biodiversity. But if agricultural production systems can intensify sustainably, then they can increase the earth’s ability to sink and store carbon and help keep us within the planet’s safe operating space.

However, right now there isn’t a single farming system that meets all the criteria to do that. At the global level, we need a revolution in nutrient management. But that revolution means different kinds of changes for the large commercial monoculture farming systems than for smallholder subsistence farmers in the tropics.

KS: Our work focuses on those smallholders you just mentioned, so what does the movement to sustainable agriculture look like for the farmers that we aim to serve?

JR: For Africa, this means increasing nutrients for agriculture and better managing the scarce water resources on the continent. So much of Africa’s soil has extremely low nutrient levels and increasing nutrients is the only way for the existing crop land to produce any more food. Upgrading rainfed agriculture through conservation agriculture and similar practices will be important for small scale African farmers to optimize their water and nutrient resources.

Conservation agriculture reduces or eliminates plowing, and in many cases leaves crop residues (the stalks and leaves left over after harvesting the food portion of the plant) on the field. This provides nutrients to the soil as residues decompose, decreases erosion, and increases the soil’s ability to hold water.

Conservation agriculture and the smart use of cover crops (crops rotated in that replenish nutrients in the soil, such as legumes) together with both organic and inorganic fertilizer will help to improve nutrient availability and management – something urgently needed for the Africa’s depleted soils. But we also need to enhance the overall availability of water to crops as well as increase crops’ efficiency in using water.

KS: This sounds like something all farmers would want to start doing, why hasn’t it been widely adopted already?

JR: The dilemma for poor farmers is how to transition into a new way of cultivating the land. For example, farmers plow as a strategy to manage weeds, and soil gets addicted to plowing. The more you plow, the fiercer weeds become, and it takes 4-6 years to move out of a weed-infested state. In addition, making the transition requires technologies and practices that are locally adapted, so that they are best suited for specific environments and the resources that are available (or unavailable) in a particular location. Unfortunately, many technologies have not yet been adapted to meet the needs of the poorest smallholder farmers.

Finally, farmers need to be knowledgeable about the technologies and practices – how to implement them on their farms and what they can expect to gain as a result – so they are well-informed to make a choice to transition. Much more work is needed in research and extension in order to provide the right tools and get the information out to farmers, particularly in Africa, but in other rural areas of the tropics as well.

The good news is there is a lot of potential, and with enough investment there is room in agriculture for a quick and productive transformation to sustainable production.