To tackle this, ICRAF scientists have used readily available data from satellites, along with 'ground-truthing' (the verification on the ground of what is seen from the satellite), to characterise changes in land use across tropical forest margins and build up a picture of carbon sequestration.
This picture relates directly to carbon stock assessments, says Brent Swallow, Global Coordinator for the Alternatives to Slash and Burn Partnership for the Tropical Forest Margins.
Swallow says that the work of ICRAF scientists in western Kenya shows that a high proportion of soil carbon is contained in relatively stable micro-aggregates, a promising sign for the longevity of carbon stored in soil. It also revealed which farming methods are best for carbon sequestration.
In recent years, Swallow told SciDev.Net, diverse research groups have produced significant improvements in earth observation technologies, modelling and other location-based technologies.
But so far, applications of these systems have not been very useful to developing countries — for example, because standards have not been consistent. These shortcomings have limited the contributions that the technological advances have been able to offer in providing guidance to project developers and managers seeking to maximise carbon benefits.
This new research can serve as a model of how to measure soil carbon accurately, say the team. According to the study, the market for carbon credits — in which polluters in industrialised countries offset their emissions by paying others to reduce their emissions — was valued at US$64 billion in 2007 by the energy firm New Carbon Finance. This figure is expected to shoot up in 2008.
The credits system is now largely rewarding countries such as China and India for carbon saved in industrial operations.
But policymakers are struggling to agree on a plan to accept carbon saved in tropical forests and agricultural landscapes into the trading system.
To reduce greenhouse gas emissions as quickly and effectively as possible, people living in and around the world's tropical forests should be encouraged to adopt carbon-saving approaches to development, said Dennis Garrity, director general of ICRAF, in a press release.