Parties to the Paris Agreement, virtually all countries, aim to hold the increase in the global average temperature to well below 2°C above pre-industrial levels and pursue efforts to limit the increase to 1.5°C. The Intergovernmental Panel on Climate Change (IPCC) recently completed an assessment of the scientific literature related to warming to 1.5°C.1 Since human activity has already increased the global mean temperature by 1°C this is a very challenging goal. A global imperative is to reduce CO2 emissions by about 45% by 2030 compared to 2010 levels and reach net-zero around mid-century. That will require rapid and extensive transitions of energy, transport, building and industrial systems to reduce fossil fuel use. Limiting warming to 1.5°C also requires increased CO2 removal by natural or anthropogenic means.

Renewable synthetic fuels could make a significant contribution to achieving the 1.5°C objective. They are common fuels such as hydrogen, methane, methanol, ammonia, gasoline, kerosene and diesel produced from biomass or CO2 and H2O feedstock’s, using renewable electricity or a combination of both. Renewable synthetic fuels could easily replace their fossil-fuel cousins thus facilitating the transition away from fossil fuels. The use of non-fossil or unavoidable fossil CO2 as a feedstock also contributes to meeting the objective.

How do we produce CO2-based synthetic fuels on the scale required? This necessitates technologies to capture CO2 from emissions streams, ambient air, or the ocean, to generate H2 from water or a mixture of CO and H2 from CO2 and water, and to produce various hydrocarbon fuels from these feedstocks. Generation of renewable electricity would have to increase greatly to meet the present fuel demand and displace existing fossil-fired generation. A technological roadmap could help academia, industry, government and stakeholders plan the changes required to produce renewable synthetic fuels on the scale required to ameliorate the deleterious consequences of climate change, Figure 1. (Read more at Advanced Science News)