Human activities are currently estimated to produce around 40 billion tonnes of carbon-dioxide equivalent every year. Model results indicate that agricultural adaptation measures would prevent around 350 million tonnes of carbon-dioxide emissions annually – equivalent to around 1% of total global emissions.

Adapting to climate change or mitigating climate change – which would you choose to invest your cash in? Mitigation and adaptation are often viewed as separate activities, with the former aiming to reduce greenhouse-gas emissions and the latter helping adjust to expected increases in greenhouse gases. A new study shows that when it comes to agriculture, adaptation measures can also generate significant mitigation effects, making them a highly worthwhile investment.

Food production is big. If farmers fail to adapt to climate change we can expect to see more land being turned over to agriculture, in order to keep up with food demand. With this in mind, David Lobell, from Stanford University, US, and colleagues used a model of global agricultural trade to investigate the co-benefits of helping farmers adapt to climate change, thereby avoiding some of the emissions associated with land-use change.

Running their model to 2050, they show that an investment of $225 bn in agricultural adaptation measures can be expected to offset the negative yield impacts associated with predicted temperature and rainfall changes. But that’s not all – the model revealed that this investment would also save 61 million hectares from conversion to cropland, resulting in 15 Gtonnes carbon-dioxide equivalent fewer emissions by 2050.

"I don't think any of us expected the mitigation benefits to be as big as they were," said Lobell, whose findings are published in Environmental Research Letters (ERL). "We had a hunch that they would be big enough to be an important co-benefit, but the fact they were often big enough to rival other mitigation activities was surprising."

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Study reveals scale of nitrogen’s effect on people and ecosystems

It’s no secret that China is faced with some of the world’s worst pollution. Until now, however, information on the magnitude, scope and impacts of a major contributor to that pollution – human-caused nitrogen emissions – was lacking.

A new study co-authored by Stanford Woods Institute Senior Fellow Peter Vitousek (Biology) reveals, among other findings, that amounts of nitrogen deposited on land and water in China by way of rain, dust and other carriers increased by 60 percent annually from the 1980s to the 2000s, with profound consequences for the country’s people and ecosystems. Xuejun Liu and Fusuo Zhang at China Agricultural University in Beijing led the study, which is part of an ongoing collaboration with Stanford aimed at reducing agricultural nutrient pollution while increasing food production in China – a collaboration that includes Vitousek and Pamela Matson, a Stanford Woods Institute senior fellow and dean of the School of Earth Sciences. The researchers analyzed all available data on bulk nitrogen deposition results from monitoring sites throughout China from 1980 to 2010.

During the past 30 years, China has become by far the largest creator and emitter of nitrogen globally. The country’s use of nitrogen as a fertilizer increased about threefold from the 1980s to 2000s, while livestock numbers and coal combustion increased about fourfold, and the number of automobiles about 20-fold. All of these activities release reactive nitrogen into the environment. Increased levels of nitrogen have led to a range of deleterious impacts, including decreased air quality, acidification of soil and water, increased greenhouse gas concentrations and reduced biological diversity.

“All these changes can be linked to a common driving factor: strong economic growth, which has led to continuous increases in agricultural and nonagricultural reactive nitrogen emissions and consequently increased nitrogen deposition,” the study’s authors write.

Researchers found highly significant increases in bulk nitrogen deposition since the 1980s in China’s industrialized north, southeast and southwest regions. Nitrogen levels on the North China Plain are much higher than those observed in any region in the U.S., and are comparable to the maximum values observed in the U.K. and the Netherlands when nitrogen deposition was at its peak in the 1980s.

China’s rapid industrialization and agricultural expansion have led to continuous increases in nitrogen emissions and nitrogen deposition. China’s production and use of nitrogen-based fertilizers is greater than that of the U.S. and the E.U. combined. Because of inefficiencies, more than half of that fertilizer is lost to the environment in gaseous or dissolved forms.

China’s nitrogen deposition problem could be brought under control, the study’s authors state, if the country’s environmental policy focused on improving nitrogen agricultural use efficiency and reducing nitrogen emissions from all sources, including industry and transit.

Africa owns 60% of the world’s uncultivated land suited for crop production, but accounts for 30% of the world’s malnourished and only 3% of global agricultural exports. If there is one thing global agricultural policy experts Paul Collier and Derek Byerlee can agree on, it’s that Africa’s food system is struggling.Their different views on the causes and investment solutions to put Africa on a more prosperous and food secure path made for a provocative discussion at a symposium hosted last week by Stanford University’s Center on Food Security and the Environment.

Collier, a distinguished economist and author of the award-winning book “The Bottom Billion”, was direct in his opening remarks.

“Smallholder agriculture has been a persistent productivity disaster for Africa,” said Collier. “Despite a huge land area to population ratio and higher proportion of its labor force engaged in food production, Africa is still not able to feed itself. The smallholder business model of the last 50 years is fundamentally flawed…maybe it is time for a Plan B.”

African agricultural productivity remains astoundingly low and stagnant at about $500 per person per year. His solution: debunk the ‘myth of the efficient peasant’ and rural romanticism and support commercial agriculture and urban growth.

Commercial agriculture reaps economies of scale that provide advantages often beyond reach for smallholder farmers yet are critical to agricultural production in Africa—risk finance, liquidity, technology, logistics, and knowledge of markets. Collier points to the success of Brazil and Thailand—two emerging economies that differ in scale of commercial organization, but have become major agricultural exporting countries.

Byerlee, a renowned economist and director of the 2008 World Development Report, agreed with Collier that commercial agriculture is likely Africa’s future, but that market-oriented smallholder farmers will play the lead role.

“We have much to learn from emerging business models,” said Byerlee. “Smallholders and agribusiness have complementary assets that can contribute to commercial agriculture, and states and investors must help facilitate smallholder inclusion in these models.”

Byerlee noted that the choice between small-scale or large-scale production models depend on transaction costs and type of commodity, and are context specific. Small- to medium scale production is best suited to most types of products in Africa especially food staples and many labor intensive products (e.g, diary). This follows the example of Thailand that not only has succeeded in food production but alone exports more than the value of all sub-Saharan Africa. Value chains that require stronger coordination with processing and shipping (e.g., sugar and palm oil), demand market standards (e.g, export horticulture) or are taking pioneering risks (e.g., new crops in new areas) may be better suited for large-scale production. Benefits may still be large if they create good jobs—a major challenge for Africa’s future.

Where to invest in Africa’s future?

"Young Africans are voting with their feet in droves to leave smallholder agriculture because it is impoverishing and boring, “ said Collier. “The economic tragedy for Africa is that cities haven’t been the engines of economic opportunity and wage employment.”

Collier argued investments in cities over agriculture are needed to prepare for an urban future and must be done quickly due to one dangerous fact—climate change.

“Climate change is the train coming down the tracks and it is already happening in Africa,” warned Collier. “The continuing deterioration of African agriculture is already set in stone. The last 50 years of carbon emissions are going to continue to devastate Africa’s climate over the next 50 years.”

Collier fears climate change will shift Africa’s competitive advantage in agriculture to Northern Eurasia and North America. Therefore, limited investment dollars must shift to cities which are more climate resilient. Byerlee disagrees.

“There is overwhelming and convincing evidence that agricultural growth is important for poverty reduction and food security,” said Byerlee. “Look at the Green Revolution in Asia and the institutional reforms in China in the early 1980s.”

The 2008 World Development Report also found GDP growth from agriculture benefits the income of the poor two to four times more than GDP growth from non-agriculture. So why isn’t this working for sub-Saharan Africa?

Byerlee points to Africa’s history of poor macroeconomic policies that have disadvantaged African farmers. Smallholder farmers have traditionally been taxed at high levels (as much as 50 percent 20 years ago before liberalization programs started kicking in). Rates have come down dramatically to 15-20 percent, but are still significantly higher than other countries.

“African states must level the playing field,” said Byerlee.

Many of these macropolicies are slowing changing, and that makes Collier and Byerlee hopeful.

“After four decades in sub-Saharan Africa I feel optimistic about Africa’s food systems and future,” said Byerlee. “I see exciting opportunities in terms of market growth, private interest, and improved policies.”

Yields in Africa are low, but there is room for significant improvement. The continent is home to potentially 240 million hectares of uncultivated land and less then 20 percent of irrigation potential has been tapped.

African agricultural systems are transforming rapidly in response to rising rates of income growth, urbanization, and shifts in demand for high value and processed food, and feed for livestock. Higher food prices are incentivizing farmers to enter the market and increasing farmer income. Regional markets now accounting for only 5-10% of trade have much potential to expand, and Byerlee projects the value of African urban food markets to quadruple over the next 20 years.

Renewed investment in Africa is another reason for optimism. After decades of declining support donor agencies are refocusing their efforts on supporting agricultural development in Africa. Private sector investment, ranging from local to foreign investors, is also increasing. Collier spoke of the value pioneer commercial investors are bringing to unused and underutilized, but arable lands in Africa. These larger investors are better able to internalize the benefits of infrastructure supply while creating jobs and opening new markets.

The spur in foreign investment has drawn some fire from opponents worried about ‘land grabbing’. Collier and Byerlee both pointed out the need to differentiate between commercial investors and land speculators. The latter are being scrutinized, and for good reason.

Land speculators are leasing huge tracts of land over long time horizons and banking on the land’s option value if there is a big spike in food prices. This takes potentially arable land out of near-term production and out of the hands of local communities. Byerlee suggests governments impose controls on how rapidly the land is developed as one way of managing this problem.

What will a successful African food system look like in 2050?

"African peasantry as we know it today will not be preserved," projects Collier.