Changes in temperature due to climate change over the next few decades will put considerable pressure on crop production in already vulnerable areas of sub-Saharan Africa, states a new study from Stanford University's Program on Food Security and the Environment published this week in Environmental Research Letters. The study found that average yields for five staple crops - maize, sorghum, millet, groundnuts, and cassava -will likely be harmed by warming without successful adaptation

"In all cases except cassava, we estimate a very high (95%) probability that damages would exceed 7%, and a low (5%) probability that they exceed 27%," said co-author David Lobell, an assistant professor of Environmental Earth System Science and center fellow at the Program on Food Security and the Environment, a joint program of the Freeman Spogli Institute for International Studies and Woods Institute for the Environment at Stanford.

The findings present a surprisingly robust picture of how weather affects yields in sub-Saharan Africa (SSA) and suggest there is a real threat of large near-term impacts in this food-insecure part of the world. SSA has the highest proportion of malnourished populations in the world, with one in three people chronically hungry.

"These are very resource scarce countries," noted lead author Wolfram Schlenker, assistant professor of economics at Columbia University, "and a reliable picture of what climate change will mean for crop yields can be very useful in allocating investments."

Panel dataset approach

Up to this point, the scientific basis for estimating production risks and prioritizing investments has been quite limited. "Many approaches have been limited by a lack of reliable data on such things as soil properties, historical agricultural data, and management practices," said Lobell. "This has not inspired a lot of confidence in the estimates, and has caused many to question some high-level statements about risks of climate change to Africa. The results presented in this study are not as disastrous as some have claimed, but they are big enough to suggest that major adaptations are needed in this region."

Schlenker and Lobell utilized a different approach than had been tried, by matching country-level yields (ton/ha) with various weather measurements for 1961-2002. By combining all the countries into a panel dataset, they were able to see a much clearer signal of weather than would be possible looking at data from individual countries.

"The observational approach enabled us to measure how farmers react to weather shocks given various, shared constraints such as credit markets and lack of required inputs," said Schlenker. "This is very difficult to do with a field trial approach."

Future research and investments

The authors emphasize that the results are not predictions of what will happen, but of what the potential stakes are if we don't take the threat seriously. Varieties with greater drought and heat tolerance, improved and expanded irrigation systems, rainwater harvesting technologies, disaster relief efforts, and insurance programs will likely all be needed to foster agricultural development and adaptation to warming.

"There is arguably little scope for substantial poverty reductions in SSA without large improvements in agricultural productivity," conclude the authors. "The findings presented here suggest that this challenge will get even more difficult in a warming climate. Rather than a cause for despair, we view this as an added incentive for serious, immediate, and sustained investments in agricultural productivity in SSA."

This work was supported by a grant from the Rockefeller Foundation. The Program on Food Security and the Environment is jointly run by the Woods Institute for the Environment and the Freeman Spogli Institute for International Studies at Stanford.

Megan Smith, Vice President, New Business Development and General Manager, Google.org., argued that greater interconnectedness achieved by information technology is a major liberating force in the world. Whether it is aiding the coordination of protests or increasing transparency of governments, the exchange of information has huge benefits. This is not a new phenomenon. In places where people have been able to exchange information easily, social progress has followed. Megan cited the example of Seneca Falls, New York where the canal system allowed for extensive communication; it became significant in both the women's rights and abolition movements.

While a large proportion of the world is benefiting from greater interconnectedness, Africa still lacks the infrastructure to take full advantage. Submarine fiber optic cables are necessary for quick and cheap internet cables and many African countries, particularly in the east, are not connected to these, relying instead on satellites. This is likely to change over the next few years, bringing great potential for further development.

The mission of Google.org is to use technology to drive solutions to global challenges such as climate change, pandemic disease and poverty. The organization was set up as part of a commitment to devote approximately one percent of Google's equity plus one percent of annual profits to philanthropy, along with employee time.  Google.org now places its strategic focus on those projects that can leverage the resources of Google staff, particularly its engineers.

Current projects that harness the power of information include:

• Google Flu Trends: This uses aggregated Google search data to estimate flu activity up to two weeks earlier than traditional methods. This system has almost 90% accuracy in real time flu prediction and is therefore an extremely useful tool for health delivery agencies. It is now being used in 30 countries. Google is also starting to work in Cambodia to collect data around SARS.
• Google Power Meter provides a system for consumers to understand their in-home energy use and to take steps to reducing this. The Meter receives information from utility smart meters and in-home energy management devices and visualizes this information on iGoogle (a personalized Google homepage).The premise underlying this project is that greater information is going to be crucial to tackling climate change and consumers ought to be able to be empowered to make informed decisions about their energy use.
• Disaster relief: In response to the Haitian earthquake, a team of engineers worked with the U.S. Department of State to create an online People Finder gadget so that people can submit information about missing persons and to search the database. Google Earth satellite images have also been used to document the extent of damage.