Engineering photosynthesis: a necessary tool to protect the world's climate?

The Paris Agreement of the UNFCCC aims at holding the increase in the global average temperature to well below 2 degrees C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5 degrees C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change.' It is difficult to see how this could be achieved without a significant use of biomass to replace fossil fuels and, in combination with carbon capture and storage, as a sink of carbon dioxide. Biomass also is essentially the only product group that can feed a growing world population, the production of biomass needs to significantly increase globally. This paper assesses the role of photosynthesis in the world's energy supply and the possibilities to engineer the photosynthetic apparatus toward higher efficiency and direct production of photosynthetic fuels. A decarbonization route through this type of technological development could significantly contribute to the transition to a global fossil-free energy system. From the users' point of view this would be an attractive route, since most of the energy systems, including transformation, distribution and final use, could remain more or less unchanged.