Biomass fuels are often branded dirty but can be harnessed in 'greener' ways through new technologies, says Duncan Macqueen.

To make an impact, small-scale renewable energy systems must fit social expectations and cultural norms, argues Benjamin K. Sovacool.

The hardy jatropha tree as a biofuel source may not be the panacea for smallholders that some have claimed, say Miyuki Iiyama and James Onchieku.

China must protect its coasts to replenish biodiversity and increase CO2 absorption, say Jiang Gaoming, Dou Guanyi and Chen Bosen.

African bioenergy projects must focus on new technologies and receive stronger political support, says biofuel expert Emile van Zyl.

New biofuels offer a sustainable source of energy but we must consider the ethical and social implications, say Joyce Tait and Banji Oyelaran-Oyeyinka.

Renewables like solar, wind and biomass could help India meet its growing energy needs and create millions of jobs, says Anil K. Rajvanshi.

Biotechnology is only one of a set of approaches needed to solve the world's problems, says an editorial in Nature Biotechnology.

The environmental and social costs of producing biofuels on land can be avoided by farming seaweed, says Ricardo Radulovich.

Dryland farmers are growing novel crops for biofuel, but domestication and research into yields and pests is still needed, says William Dar.

Strong international policies are needed to stop the biofuel revolution threatening food security for the poor, says Siwa Msangi.

Biofuel production offers a lifeline to sugar-producing countries hit by the European Union's 2006 sugar reforms, argues Maureen Wilson.

Biofuels offer huge potential, but pose challenges best countered with strong and coherent development policies, says S. Arungu-Olende.

Brazilian president Luiz Inácio Lula da Silva, stands up for biofuels' role in sustainable development.

China is increasing its use of bioenergy. But the government is overlooking smaller projects that could benefit poor rural communities, says Lin Gan.

Growing biofuels could put pressure on scarce water supplies in poorer countries, argues Charlotte de Fraiture.

The world must take measures to combat climate change now if it is to achieve global sustainability, say Rosina M. Bierbaum and Peter H. Raven.

Developing countries should copy Brazil's programme for producing sugarcane ethanol as a sustainable energy source, says José Goldemberg.

Last month, SciDev.Net launched a discussion group to ensure the views of African scientists, policymakers, communicators, funders and investors are heard in the run-up to the African Union summit.

Jeffrey McNeely says proponents of biofuels need to take greater account of their environmental impacts and use science to make them more efficient.