Climate protection: The use of biomass for obtaining energy has a large sustainability potential, because in principle it is beneficial to the reduction of greenhouse gas emissions, in particular CO2 emissions. However, this is sometimes undermined if generating and processing the biomass itself entails a major expenditure of energy (covered by fossil-based sources) or if, in order to create space for the cultivation of the biomass, jungles are cleared and swamps are drained, thereby releasing large quantities of greenhouse gases. Under some circumstances these quantities are greater than the savings of no longer using fossil-based fuels. As a consequence, the use of bio-energy must match certain framework conditions that need to be critically challenged and monitored continuously.
Diversity of species: The same applies here – subject to having the right framework conditions, bioenergy has the potential to contribute to the diversity of species. After all, the wide range of energy crops and other renewable natural resources is significantly greater than the current, rather limited spectrum of plants used for food and animal feed production. And yet the change has begun: for instance, the Renewable Energy Sources Act (EEG) has stipulated that farmers in Germany are not permitted to use only maize in their biogas plants, brought into service in or after 2012, if they wish to continue to get the remuneration established in the EEG.
Substances hazardous to the environment: A wood heating system emits more particulate matter than a gas-powered heating system does, but biodiesel is less hazardous to water than fossil-based diesel. A non-covered post-digester used in a biogas plant releases ammonia, but so does a conventional slurry container. Other examples could be listed making the same point. Conclusion: again, reality is not a black-and-white matter. As a general observation, biomass is less toxic and hazardous to the environment than fossil based natural resources, but in a particular situation the issue is always HOW it is being used. Yet here also, through technical development and appropriate framework conditions, sustainability can constantly be further enhanced, step-by-step – thus, for example, modern wood-fuelled heating systems are emitting much less particulate matter and due to what by now is the legally-binding obligation to seal the post digester gas-tight, the ammonia emissions from biogas plants are prevented to a large degree.