Global warming, climate change and the role biotechnology can play in mitigating its effects.
People often talk about the uncertainties of climate change because scientists are uncertain about the exact impact global warming will have, but the broad tendencies are actually very clear said Dr Bob Scholes, from the Council for Scientific and Industrial Research’s (CSIR’s).
There will be an increase in atmospheric carbon dioxide, at a rate ahead of the worst-case projections. As a consequence we are likely to see an increase in temperature between two degrees and five degrees centigrade.
Scholes said the reason for the uncertainty in the temperature range was in part due to spatial variability. For example largest increase in temperature will take place in the Polar Regions, and the second highest increase will take place in the sub-tropical area of air convergence which falls largely over the Southern African Development Community (SADC) region. Here the area is largely cloud free and will feel the full impact of warming, more in the interior than in coastal areas, and more in an increase in minimum (night) temperatures than maximum temperatures, explained Scholes.
Generally rainfall will increase, by up to 15% but for SADC there is a strong indication that there will be a drying trend, but the frequency of high intensity rainfall events, with potential flood damage, will increase.
Scholes said there is scientific evidence of a loss of USD 23/hectare per degree increase in temperature in Africa, with the rise in temperature affecting grain yield more than plant growth.
This all has important implications for biodiversity, food security and pest control said Scholes.
The climate is not the only thing that is changing. There has been an enormous increase in the human population and a change in dietary habits to include more animal protein as a result of an increase in wealth.
We can’t feed people using wild harvested resources anymore. We need to expand production vertically by increasing the productivity of our land – and we need to learn how to do it with fewer resources, using less water, less energy…
We face an unprecedented challenge to increase crop production and biotechnology is one of the tools we can use to adapt to climate change. There is some scope for adaptation, but not an enormous amount. There is not one single intervention… said Scholes.
Dr Sylvester Mpandeli from the Agricultural Research Council in South Africa said that investing in agricultural research, technology and development plays a critical role in stimulating farmers’ production, increasing food security and combating poverty.
The ARC has 719 automatic weather stations around the country recording data every five minutes which acts as an early warning system for diseases and weather patterns and is useful for irrigation scheduling and making decisions about when to apply fertiliser.
Mpandeli said the ARC has run two pilot projects supplying farmers with relevant information online or via SMS and farmers are asking for this service to be expanded across the country.
In addition to working on gene banks for all major crops, including potatoes, sweet potatoes, maize, wheat and cowpea, the ARC is encouraging farmers to adopt a number of adaptation strategies.
These include the use of mulch to keep the ground moist, multi-cropping to reduce the risks of single crops and planting mixed crops, like ground nuts, mazie and cowpeas, which allows for more ground cover, and helps to conserve water and control weeds.
Dr Rachel Chikwamba chief scientist at the CSIR’s biosciences said that drought stress is likely to affect crops sub-Saharan Africa, and that drought can halve production in maize by 50% having a serious impact on food security and the region’s ability to meet some of the Millennium Development Goals.
She said advanced biosciences can play a role in crop production systems management (as highlighted by Mpandeli) and in the development of new cultivars that are likely to respond better to climate change.