Is there a "crystal ball"? Assessing environmental life cycle impacts of new nanomaterials
Paper in proceeding, 2013
Many new nanomaterials are currently being developed, and assessing the life cycle environmental impacts related to these materials and products that contain the materials, e.g. in terms of emissions and energy use, constitutes a great challenge. The challenge is much due to the many uncertainties that surround new nanomaterials at this early point of technological development, which makes the application of environmental assessment methods such as life cycle assessment difficult to apply. These uncertainties include the future areas of application of the nanomaterial, future designs of products within those areas, and the future production processes that will be needed to produce such products. When one or more of these uncertainties are present, we say that the product chain or life cycle is embryonic. This embryonic nature of nanomaterial life cycles differentiates them from more established products, such as cement and cucumbers. We provide a number of examples of a number of embryonic nanomaterial life cycles, including carbon nanotubes in composites, titanium dioxide nanoparticles in self-cleaning cement and graphene in electronic devices and composites, illustrating their embryonic nature. Assessing the environmental impacts of embryonic nanomaterial product chains requires the assessor to use different future studies approaches, i.e. to use a “crystal ball” to understand the future or rather different possible futures. Existing approaches include monitoring, predicting, exploring, and sometimes even fantasizing. We show how some of these approaches have been used in previous life cycle studies on nanomaterials, illustrating that they may all be relevant to include in environmental assessments and life cycle assessments in particular, but also that they can be misused or used in questionable ways. The important thing is to know which approach to apply in a certain situation in order to ensure a relevant assessment, and to avoid uses that leads to more confusion than knowledge.