Authors of a new study, published on Friday (2 August) in the journal Science, has called for the creation of a 'climate-smart food system' to prevent climate change from slowing progress in eradicating global hunger.

The researchers behind the calls carried out a review of key scientific papers on food security and climate change published since 1990. They said the weight of research confirms a global pattern of climate change impacts on crop productivity that could have consequences for food availability.

In the UK, the government has come under fire for failing to drive climate change mitigation and adaptation strategies with sufficient urgency, and in June, Environment Secretary Owen Paterson was heavily criticised for remarks made during a BBC Radio Any Questions debate, which revealed an apparent lack of understandingabout climate science.

Scientists at Reading University, who contributed to the review published this week, suggested improvements in agricultural technologies, such as more productive and climate-resilient crop varieties will prove important in countering the threats posed by climate change, but warned that they "are unlikely to be sufficient on their own." The scientists elaborated that "Wider changes in food trade and stocks, and nutrition and social policy options are also critical."

They said that, since 2007, progress in tackling world hunger has slowed and food supply and demand around the world have been precariously balanced - climate change threatens to tip this balance, most dramatically in the poorer areas of the world.

Professor Tim Wheeler, the review's lead author, outlined the researchers' demands, "The food price spike of 2008 highlights the increasing vulnerability of the global food system to shocks, such as extreme weather and economic volatility. A step change is needed in efforts to create a 'climate-smart' food system that can better withstand whatever climate throws at us. This should include development of drought- and heat-tolerant crops or new tillage techniques that reduce release of carbon from soils, but we need to go further and ensure trade, investment and development policies all have 'climate-smart' food as a central goal."

Warmer temperatures, changes in rainfall patterns and more extreme weather under climate change are expected to affect food and fodder production, change patterns of pest and diseases of crops and animals and impact on food supplies. Countries where these impacts are expected to be negative are also those where hunger is most prevalent now.

Extreme weather, such as floods, drought and heatwaves, contributes to short term food price spikes and longer term climate change is likely to be an important factor in future price trends. Volatile food prices are a particular concern to the poor, who often spend a high proportion of their income on food.

Professor Joachim von Braun, from Bonn University's Center for Development Research in Germany and a co-author of the paper, said, "Human suffering due to the climate change impacts on food security is increasing. And the costs of short term food crises mitigation will grow, if meaningful investments for more resilient food systems are further delayed."

The researchers said a broad set of risks to food security needs to be considered, of which climate change is an increasingly important one. They warned its effects can increase food market volatility by impacting on both supply and demand, destabilising food systems and causing spikes in food prices that mean the poorest will not be able to afford staple foods. The team added, "This complex system of risks can assume a variety of patterns that could potentially collide in catastrophic combinations."

One study reviewed found that an average of 17 percent drop in yields of wheat in Africa by 2050 and a 16 percent drop in maize yields in South Asia over the same period are likely result to result from climate change.

Importantly, the impacts of climate change on food go much further than the direct effects of weather on crop harvests. For example, a loss of access to drinking water can cause diarrhoea and so reduce the goodness derived from food. Relatively little research has been done on such indirect effects of climate change on food security, the researchers concluded. They added that, as well as action to address the direct impacts of climate change, more research is needed on the broader, indirect aspects and their implications for food security.