As much as one fifth of the world’s energy could be provided by biomass materials without reducing farming land space used for growing food, according to the latest comprehensive scientific report.

Biomass is biological material obtained from living or recently living organisms that can be processed into electricity, fuel and heat. Biomass for energy can be obtained from a diverse range of sources, the most important of which are energy crops, agricultural and forestry residues, wastes and existing forestry.

But debate continues to surround the role of biomass in the future energy system, with some believing it has the potential to fuel the planet, and others fearing it could ruin the environment.

Many believe biomass can address concerns relating to climate change, energy security, rural developmentÊandÊaccess to modern energy services in developing countries.

To establish the facts, scientists at Imperial College have reviewed the size of the global resource of energy from biomass, examining evidence from more than 90 international studies.

The report addresses key controversies in the energy field and the main concerns relating to the production of biomass including the sustainability of increasing crop yields and the prospect that competition for land will impact on food production.

According to the report, the main reason that scientists disagree on biomass is that they make different technical and ethical assumptions about population, diet, and land use. One major disagreement concerns the speed with which productivity improvements in food and energy crop production can be rolled out.

“If we make the best use of agricultural residues, energy crops and waste materials, then getting one fifth of current global energy supply from biomass is a reasonable ambition,” said Dr Raphael Slade, the report’s leading author and a research fellow at Imperial College London.

Achieving more than a fifth is technically possible but would result in having to make challenging assumptions about global food production and changes in diets.

The report establishes that societal preferences concerning food, energy and environmental protection will be key factors in deciding the extent to which biomass is used to provide energy services in the future.

“The more bio-energy you want, the harder it becomes to reconcile demand for food, energy and environmental protection,” added Dr Slade. “Replacing all fossil fuels with biomass would be equivalent to all of global agriculture and commercial forestry combined, and would only be possible if we can grow more food on less land.”

Bio-energy production could most easily be increased by technical advances, but policy will need to encourage innovation and investment, according to the report.

“A renewed focus on increasing food and energy crop yields could deliver a win-win opportunity as long as it is done without damaging soil fertility or depleting water resources,” he said.

Learning from the development of sustainable biomass now should be encouraged by policymakers, rather than waiting to see what the future potential will actually be. “The main mistake is to think of this as all or nothing. There’s plenty of scope for experimentation to make sure we get it right,” added Dr Slade.

The report highlights the need for scientists researching on food and agriculture to work more closely with bio-energy specialists to address challenges such as water availability and environmental protection.

Dr Ausilio Bauen, who is head of bioenergy at Imperial College’s Centre for Energy Policy & Technology, said: “Bioenergy may need to play a part in a future low-carbon energy mix.”

He concluded: “Ensuring bio-energy, food and forests do not compete for land would not be straightforward. But if we use land more productively, and make better use of available plant material, we should be perfectly capable of producing bio-energy, feeding a growing population and conserving the environment all at the same time.”