Oslo, August 19, 2014
While many believe agricultural intensification to be harmful for the environment, Stanford scientists found that high yield agriculture has prevented CO2 emissions of up to 590 billion tons in the period 1961 to 2005.
- -13 billion tons CO2 per year through yield increases
- Deforestation the size of Russia avoided
- USD 7.50 or less per ton CO2 mitigated
“We started out asking ourselves, what would have happened if this massive push in intensification didn’t take place? The answer is that, clearly, intensification saved a lot of greenhouse gas emissions. We would have been worse off, from a climate perspective, without the yield increase,” says Jennifer Burney, assistant professor at UC San Diego.
Land conversion avoided
Together with Assistant Professor Steven Davis at UC Irvine, and Associate Professor David Lobell at Stanford, she wanted to look at the period of the so-called green revolution, when a combination of fertilizers, improved seeds and access to irrigation and mechanization led to significant yield increases in agriculture.
These yield improvements in turn have reduced the need to convert natural carbon banks such as forests and grassland to farmland, which generates carbon dioxide and other greenhouse gases.
The conclusion, published in their paper “Greenhouse gas mitigation by agricultural intensification” in Proceedings of the National Academy of Sciences in 2010, was that high-yield agriculture in the period 1961-2005 prevented the equivalent of up to 590 billion metric tons of carbon dioxide gases from entering the atmosphere.
“Our results dispel the notion that modern intensive agriculture is inherently worse for the environment than a more 'old-fashioned' way of doing things," says Burney.
Cost effective method
Burney and her colleagues also calculated that for every dollar spent on agricultural research and development since 1961, emissions of the three principal greenhouse gases – methane, nitrous oxide and carbon dioxide – were reduced by the equivalent of about a quarter of a ton of carbon dioxide. That is a very high rate of financial return compared to other approaches to reducing the gases.
“The potential of climate mitigation through improved yields is very high, and this is a relatively cheap strategy with clear food security co-benefits. However, this assumes that high yields spare land from conversion. We need to be aware that, for example, high crop prices are also an incentive for the farmer to expand into the nearby forest,” Jennifer Burney explains.
Her research has been well received. However, she feels the agricultural sector can do more regarding adaptation to climate change, but there is concern within the climate community that adaptation efforts can distract attention from mitigation.
Farmers: Good scientists and good economists
“I think one of the nice things about agriculture and climate mitigation is that the incentives are potentially very much aligned at the individual level. The farmers want to maximize profits and continue to live off the land. To me, farmers are both good scientists and good economists, which means there are some nice climate co-benefits to be realized from smart agriculture,” says Burney.
She is currently involved in several research projects on land use change, as well as looking at climate adaptation on the ground with smallholders.
“I´ve been very heartened by efforts in the private sector to improve yields via input efficiency,” says Burney.