Will agricultural intensification save our natural ecosystems from farmer invasion?

He is the most revered figure in agricultural research – the father of the green revolution. But the late Norman Borlaug’s influence extends further even than delivering the seeds that have fed the world. He also established in agricultural and environmental orthodoxy what is known today as the Borlaug hypothesis -- the idea that intensifying agriculture is also the key to saving forests and other natural ecosystems from invasion by farmers.



Photo: BGRI Norman Borlaug in the wheat fields at CIMMYT's headquarters, 2006.Photo: BGRI

The idea underpins research priorities in agriculture, for which increased yield is to holy grail. More surprisingly perhaps, it sustains conservationists who want to abandon green notions of low-intensity organic agriculture in favour of giving agriculture its head.

Now the argument is being deployed in the debate over a future global climate change deal. Some advocates of REDD, which would provide finance for protecting forests as carbon stores, say carbon offsetters should be encouraged to fund intensified farming too. It is one facet of the push for “climate-smart” agriculture that we will heard again at the next climate talks in Doha later this year.

Lord Nicholas Stern, the British economist behind the highly influential Stern Review on the economics of climate change, puts the Borlaug hypothesis this way: “Cattle pasture in Brazil has only one animal per hectare. Raise that to two animals and you can save the Amazon rainforest.”

But is it true? If farming were a zero-sum game, with a simple aim of growing enough food to feed the world, then clearly intensification should spare land for nature. But market forces may have perverse effects.

The Contrarian View

The counter-argument is that farmers don’t clear forests to feed the world; they clear forests to make money. So helping farmers become more efficient and productive won’t reduce the threat. It will increase it, by encouraging them to expand, and increasing their resources to do it.

Carpenter in forest near village of Ovangoul, Central Region, Cameroon. Photo: CIFOR

As Tony Simons, deputy director of the World Agroforestry Centre in Nairobi, put it to me a year or so back: “Borlaug thought that if you addressed poverty in the forest border, they’d stop taking their machetes into the forest. Actually, they get enough money to buy a chainsaw and do much more damage.”

Recent studies give weight to this contrarian view. Thomas Rudel of Rutgers University, New Jersey, compared national trends in agricultural yields and how much land is under crops. If Borlaug was right, then countries with fast-rising yields should see less increase in croplands, perhaps even a decrease. Sadly, he found no such link.

Robert Ewers of the Zoological Society of London reported that increased yields of staple food crops do not spare the land, but stimulated increased planting of other crops, including non-food crops like cotton, rubber and biofuels. As a result, he concluded, “land sparing is a weak process that only occurs under a limited set of circumstances.”

Economists are not surprised

That’s how markets work, they say. Arild Angelsen, of the Norwegian University of Life Sciences and senior associate at CIFOR, modelled the competing influences and concluded that, contrary to the Borlaug hypothesis, “local yield increases tend to stimulate agricultural encroachment”.

Globalization increases the stimulus. After all, Brazil’s assault on the Amazon in the late 20th century was driven not by an imperative to feed its own population, but by its successful drive to become the world’s biggest agricultural exporter. Similarly only a fraction of the palm oil grown on Indonesia’s former forests is for domestic use.

Rudel has suggested that the Borlaug hypothesis is confounded by a modern version of the Jevons paradox. The 19th century British economist William Jevons pointed out that during the industrial revolution, increased efficiency in coal burning led to more coal being burned, rather than less. Similarly today, more intensive agriculture may stimulate rather than defuse the clearance of land for new farms.

Can the Bourlaug hypothesis help tackle climate change?

There are other reasons to question Stern’s suggestion that the Borlaug hypothesis could help tackle climate change. Even if agriculture did spare forests, it also massively increases farming’s carbon footprint. Might those emissions swamp any gains from protecting forests?

A study by Jennifer Burney and others at Stanford in 2010 suggested not. After balancing both influences, she estimated a net benefit to the atmosphere from agricultural intensification of 590 billion tonnes of carbon dioxide in the past 50 years.

But surely that depends on the timescale you use. A mature forest is can only sequester so much carbon, while agricultural emissions continue for as long as the land is cultivated. Run the clock forward and the balance may be reversed.

None of this is to say that intensification won’t be needed. The world has to be fed, after all.

But the simple belief that deploying agribusiness to drive up farm yields will deliver forest protection seems economically illiterate. And the even simpler notion that investment in the intensification of agriculture can have a direct carbon payback seems dangerous folly.