10 Apr 2014: Analysis

Will Increased Food Production
Devour Tropical Forest Lands?

As global population soars, efforts to boost food production will inevitably be focused on the world’s tropical regions. Can this agricultural transformation be achieved without destroying the remaining tropical forests of Africa, South America, and Asia?

by william laurance

I once stumbled out of a jungle in the Congo Basin and startled two Bantu farmers — both women — tending a small field. I spoke no Bantu and they no French, and so we just stared at each other, a little warily, until one of their toddlers wailed and we all shared a laugh.

For the Bantu, farming has changed little in 3,000 years. The women still work small farming plots made by slashing and burning the rainforest.

View Gallery
Farmers in Gabon

William Laurance
Small-scale farmers, such as these Bantu women in Gabon, have a relatively light impact on the environment.
They plant crops like yams and bananas, while their men hunt or talk village politics. It’s a precarious existence, but the slash-and-burn farmers can eke out a living if their numbers are low enough and game abounds in the nearby forest.

Increasingly, though, this picture is changing. The Bantu are multiplying quickly, as are many other peoples across Africa. The United Nations’ mid-range population projections for the continent are staggering, with the number of Africans expected to nearly quadruple from 1.1 billion today to 4.2 billion in 2100. Feeding that populace will be an enormous challenge, requiring, among other things, a gigantic boom in agriculture.

The world’s tropical regions will surely be the epicenter of the scramble to increase food production for a global population projected to soar from 7 billion today to 11 billion by the end of the century. The tropics are where crops grow the fastest, where land is often relatively cheap, and where food demand will surge the most. But the rapid agricultural expansion in tropical regions will have profound environmental consequences for rainforests, savannas, and other ecosystems already suffering widespread destruction.

The key question facing agricultural experts, scientists, and conservationists is whether this expansion of food production can be accomplished using a reasonably small area of the tropics, or whether
If we farm as we’ve done in the past, we’d need an area the size of Canada of new farmland.
unsustainable agricultural practices will gobble up large ecosystems in Africa, South America, and Asia.

Two colleagues and I recently wrote a major review paper on the dramatic growth of tropical agriculture this century and its likely impacts on ecosystems and biodiversity. It was a sobering exercise. For starters, global food demand is expected to double by 2050. That’s a daunting prospect given that we already farm an area the size of South America and graze livestock over an area the size of Africa. This rising demand is being driven not only by population growth but also by increasing meat, poultry, and dairy consumption in the world’s emerging economies.

How much additional farmland will we need? That, it turns out, is a topic riddled with uncertainties. A research team led by ecologist David Tilman of the University of Minnesota extrapolated linearly into the future, assuming we’d continue farming much as we’ve done in the past. Under those conditions, they estimated, we’ll need around 1 billion hectares of additional farmland — an area the size of Canada.

However, a panel of experts at the U.N. Food and Agricultural Organization produced a far sunnier estimate. They suggested that agricultural yields in developing countries could double by 2050 and that we’ll require just 120 million hectares of additional farmland by mid-century — about the size of South Africa.

Why is the second estimate so much lower? Unlike the first, it assumes agriculture will change profoundly in the coming decades — that, via a Herculean effort, we will continue the remarkable strides in farm production seen during the Green Revolution.

The adherents of this view look at small-scale farming like that practiced by the Bantu farmers and see serious inefficiency — a large gap between how much food is being produced now and what could potentially be grown using modern agrotechnology. They want to turbocharge tropical farming by bringing in investment, fertilizers, machinery, and modern crop varieties, including, potentially, GMOs. They also want to improve irrigation, transportation, and energy infrastructure, and replace small
Low-intensity farms will increasingly be replaced by intensively managed monocultures.
farms with bigger farms and agribusinesses. Forget little plots of bananas and yams — this is about vast fields of soy, oil palm, and sugarcane.

Such a dramatic transformation is already happening in many tropical regions and it is probably unavoidable to a degree, because industrial-scale farms unquestionably produce more food per hectare than do small-scale farmers. But what are the implications?

Although they are more efficient, large-scale farms come with well-known environmental costs. Profitable, intensively farmed crops such as oil palm and soy are already expanding rapidly in the tropics, often at the expense of forests. In addition to causing outright habitat destruction, the proliferation of such crops means that human-dominated lands will become more hostile to biodiversity. Low-intensity farms that feature a variety of crops will increasingly be replaced by intensively managed monocultures.

Agricultural intensification will also mean a lot more infrastructure — more roads, railroads, hydroelectric dams, and power lines. Roads are expanding rapidly into the world’s last tropical wildernesses and are bringing with them forest colonists, hunters, gold miners, and land speculators. For instance, dozens of major new ‘growth corridors’ for roads and land development are being planned in sub-Saharan Africa. Tanzania’s central corridor will cut across the country to access gold, copper, and other minerals in central Africa. The Maputo corridor will penetrate into southern Africa for the exploitation of heavy mineral sands. Both will open vast expanses of land to colonization and farming.

Intensifying agriculture could have serious impacts on biodiversity. Large-scale farmlands are likely to create impassable barriers for many species, contributing to the corrosive effects of isolation on wildlife populations. In India, for instance, it’s been shown that tigers can move hundreds of kilometers across landscapes peppered with small-scale farms,
Farming is the main reason that tropical forests have retreated from 17 to 11 million square kilometers.
but it’s difficult to imagine this happening if intensive, large-scale farms were to become the dominant land use there.

Already, many nature reserves in the tropics are becoming isolated as expanding human populations and land uses encircle them. In a 2012 study, my colleagues and I showed that tropical forest reserves encircled by hostile, human-dominated lands suffer far more serious losses of biodiversity than do those surrounded by native vegetation. To a degree, the nature reserves act like mirrors — reflecting the biological condition and health of ecosystems around them.

Which tropical regions will be most affected by the coming avalanche of land-use change? Experts see especially dramatic changes ahead for sub-Saharan Africa and South America. Agriculture will expand not only in biodiversity-rich rainforest areas such as the Congo Basin and Amazon, but also in semi-arid ecosystems such as the Pantanal of South America and the Guinea and Miombo savanna-woodlands of Africa — areas also profoundly important for nature. These drier habitats sustain some of the most densely populated wildlife communities in the world, including most of Africa’s iconic large mammals such as savanna elephants, lions, zebras, and giraffes.

In the tropics, much has already been lost to agriculture. Farming is the main reason that tropical forests across the planet have retreated over the past century from 17 million to 11 million square kilometers, with remaining forests projected to shrink by another third by 2050. Forests have been hugely diminished in many tropical regions, such as the
Intensive farming should be concentrated in areas where vegetation has already been cleared.
Brazilian Atlantic forests and the island forests of the Philippines and Madagascar, among many others. Forests in these areas persist mainly as small, isolated fragments that have been overhunted or scarred by fires or logging.

There is no getting around the fact that feeding up to 11 billion people is going to have profound effects on tropical nature. What can be done to minimize the impacts?

One key goal, I believe, is to concentrate intensive farming into areas where the native vegetation has already been largely cleared. This would allow farm yields to be increased while hopefully sparing forests and other wildlife habitats for nature conservation.

We’re a long way from achieving this, however, given the rapid and rather chaotic way that agriculture is spreading throughout the tropics. To control the burgeoning footprint of agriculture, we need more stringent and effective land-use zoning and enforcement. This must include efforts to limit road expansion into tropical forests. For this reason, my colleagues and I are currently developing a ‘global road-map’ to help guide road expansion in the future — identifying areas where roads should and should not be allowed, to maximize their benefits for agriculture while minimizing their overall environmental costs.

Our goal is to see this global road map integrated into land-use planning — especially in developing nations, which is where most new roads are being constructed. We plan to promote our scheme via a website that provides easy access to high-resolution zoning maps and alliances with others working internationally on road-planning issues. By proactively identifying


In the Pastures of Colombia,
Cows, Crops and Timber Coexist

Colombian agroforestry
As an ambitious program in Colombia demonstrates, combining grazing and agriculture with tree cultivation can coax more food from each acre, boost farmers’ incomes, restore degraded landscapes, and make farmland more resilient to climate change.
the areas where roads will cause the greatest environmental harm and generate the fewest benefits, we believe we can have a positive influence.

Although large-scale agriculture will probably expand a lot, there will still be many millions of small-scale farmers in the tropics. A key goal here is to introduce principles of landscape design and agroecology to make small-scale farming more efficient — raising crop yields and sustainability while also helping them be as nature-friendly as possible.

We must also bear in mind that the 21st century will be a time of enormous change and challenges. How much land gets converted to farming, and what kinds of farming, could ultimately depend on such factors as the amount of land devoted to biofuels and the stability and price of energy supplies, which are crucial for intensive mechanized agriculture. Another wild card is the specter of future climate change and how this will affect farming and nature. And of course a key issue is whether soaring birth rates in places like sub-Saharan Africa can be brought under control through effective family planning.

To counter such uncertainties, phrases such as ‘resilience’ and ‘adaptation’ need to be at the forefront of our thinking. Our great challenge is to forge a future where peoples such as the Bantu and tropical nature can both flourish.

POSTED ON 10 Apr 2014 IN Biodiversity Business & Innovation Forests Policy & Politics Sustainability Sustainability Africa North America 


Population is the prime driver… it determines the intensity and expansiveness of land use for any purpose.

Without a keen recognition of this evolutionary will to reproduce unwittingly and without regard for well-being, humans will destroy themselves and most organisms that have evolved with them.

Focusing exclusively on land use, agricultural productivity, etc only obscures the issue and delays the solution.

Let's open our eyes and complete the insight of Copernicus and Galileo, who moved the planet from the epicenter of the solar system, but who we continue to fail through our homo-centric vision… to what could be our long term detriment.
Posted by Kathryn Papp on 15 Apr 2014

I admire the work being done to increase agricultural output, but isn't it in a sense futile? This article states that the population of Africa will quadruple by 2100. And then what? Is there the thought that the population will suddenly decide to stop procreating at that point?
Posted by John Dyer on 16 Apr 2014


Comments are moderated and will be reviewed before they are posted to ensure they are on topic, relevant, and not abusive. They may be edited for length and clarity. By filling out this form, you give Yale Environment 360 permission to publish this comment.

Email address 
Please type the text shown in the graphic.

william lauranceABOUT THE AUTHOR
William Laurance is a distinguished research professor and Australian Laureate at James Cook University in Cairns, Australia, and also holds the Prince Bernhard Chair in International Nature Conservation at Utrecht University in the Netherlands. In earlier articles for Yale Environment 360, he explored the role field biologists can play in deterring poachers and scientists' fight to preserve Borneo's Danum Valley.



On Slopes of Kilimanjaro, Shift
In Climate Hits Coffee Harvest

Rising temperatures and changing precipitation are taking a toll on coffee farms worldwide, including the plantations around Mount Kilimanjaro. If the world hopes to sustain its two billion cup-a-day habit, scientists say, new climate-resilient species of coffee must be developed.

The Methane Riddle: What Is
Causing the Rise in Emissions?

The cause of the rapid increase in methane emissions since 2007 has puzzled scientists. But new research finds some surprising culprits in the methane surge and shows that fossil-fuel sources have played a much larger role over time than previously estimated.

New Green Challenge: How to
Grow More Food on Less Land

If the world is to have another Green Revolution to feed its soaring population, it must be far more sustainable than the first one. That means finding ways to boost yields with less fertilizer and rethinking the way food is distributed.

Can Data-Driven Agriculture
Help Feed a Hungry World?

Agribusinesses are increasingly using computer databases to enable farmers to grow crops more efficiently and with less environmental impact. Experts hope this data, detailing everything from water use to crop yields, can also help the developing world grow more food.

For U.S. Tribes, a Movement to
Revive Native Foods and Lands

On ancestral lands, the Fond du Lac band in Minnesota is planting wild rice and restoring wetlands damaged by dams, industry, and logging. Their efforts are part of a growing trend by Native Americans to bring back traditional food sources and heal scarred landscapes.


MORE IN Analysis

How Far Can Technology Go
To Stave Off Climate Change?

by david biello
With carbon dioxide emissions continuing to rise, an increasing number of experts believe major technological breakthroughs —such as CO2 air capture — will be necessary to slow global warming. But without the societal will to decarbonize, even the best technologies won’t be enough.

With Trump, China Emerges
As Global Leader on Climate

by isabel hilton
With Donald Trump threatening to withdraw from the Paris Agreement, China is ready to assume leadership of the world’s climate efforts. For China, it is a matter of self-interest – reducing the choking pollution in its cities and seizing the economic opportunities of a low-carbon future.

What a Trump Win Means
For the Global Climate Fight

by david victor
Donald Trump’s ascension to the presidency signals an end to American leadership on international climate policy. With the withdrawal of U.S. support, efforts to implement the Paris agreement and avoid the most devastating consequences of global warming have suffered a huge blow.

The Methane Riddle: What Is
Causing the Rise in Emissions?

by fred pearce
The cause of the rapid increase in methane emissions since 2007 has puzzled scientists. But new research finds some surprising culprits in the methane surge and shows that fossil-fuel sources have played a much larger role over time than previously estimated.

As Arctic Ocean Ice Disappears,
Global Climate Impacts Intensify

by peter wadhams
The top of the world is turning from white to blue in summer as the ice that has long covered the north polar seas melts away. This monumental change is triggering a cascade of effects that will amplify global warming and could destabilize the global climate system.

How Climate Change Could Jam
The World's Ocean Circulation

by nicola jones
Scientists are closely monitoring a key current in the North Atlantic to see if rising sea temperatures and increased freshwater from melting ice are altering the “ocean conveyor belt” — a vast oceanic stream that plays a major role in the global climate system.

Wildlife Farming: Does It Help
Or Hurt Threatened Species?

by richard conniff
Wildlife farming is being touted as a way to protect endangered species while providing food and boosting incomes in rural areas. But some conservation scientists argue that such practices fail to benefit beleaguered wildlife.

What Would a Global Warming
Increase of 1.5 Degrees Be Like?

by fred pearce
The Paris climate conference set the ambitious goal of finding ways to limit global warming to 1.5 degrees Celsius, rather than the previous threshold of 2 degrees. But what would be the difference between a 1.5 and 2 degree world? And how realistic is such a target?

After Paris, A Move to Rein In
Emissions by Ships and Planes

by fred pearce
As the world moves to slash CO2 emissions, the shipping and aviation sectors have managed to remain on the sidelines. But the pressure is now on these two major polluting industries to start controlling their emissions at last.

Abrupt Sea Level Rise Looms
As Increasingly Realistic Threat

by nicola jones
Ninety-nine percent of the planet's freshwater ice is locked up in the Antarctic and Greenland ice caps. Now, a growing number of studies are raising the possibility that as those ice sheets melt, sea levels could rise by six feet this century, and far higher in the next, flooding many of the world's populated coastal areas.

e360 digest
Yale Environment 360 is
a publication of the
Yale School of Forestry
& Environmental Studies


Donate to Yale Environment 360
Yale Environment 360 Newsletter



About e360
Submission Guidelines

E360 en Español

Universia partnership
Yale Environment 360 articles are now available in Spanish and Portuguese on Universia, the online educational network.
Visit the site.


e360 Digest
Video Reports


Business & Innovation
Policy & Politics
Pollution & Health
Science & Technology


Antarctica and the Arctic
Central & South America
Middle East
North America

e360 VIDEO

A look at how acidifying oceans could threaten the Dungeness crab, one of the most valuable fisheries on the U.S. West Coast.
Watch the video.


The latest
from Yale
Environment 360
is now available for mobile devices at e360.yale.edu/mobile.


An aerial view of why Europe’s per capita carbon emissions are less than 50 percent of those in the U.S.
View the photos.

e360 VIDEO

An indigenous tribe’s deadly fight to save its ancestral land in the Amazon rainforest from logging.
Learn more.

e360 VIDEO

Food waste
An e360 video series looks at the staggering amount of food wasted in the U.S. – a problem with major human and environmental costs.
Watch the video.

e360 VIDEO

Choco rainforest Cacao
Residents of the Chocó Rainforest in Ecuador are choosing to plant cacao over logging in an effort to slow deforestation.
Watch the video.

e360 VIDEO

Tribal people and ranchers join together to stop a project that would haul coal across their Montana land.
Watch the video.