The role of fossil fuels in a sustainable energy system.

• Author: Foster, Scott

Climate change is one of the greatest challenges of our time. Equally important, however, is the need to ensure access to energy for quality of life and for economic development. It is therefore critical to address climate change as part of the sustainable development agenda. Ongoing progress in the development of new technologies has brought confidence and hope that these objectives will be met in the energy system. Dramatic price reductions and technological advancement of wind generators and solar photovoltaics have shown that these renewable energy resources can be important players in global electricity systems, and that the long-anticipated breakthrough in cost-effective storage technology would shift primary energy mixes substantially.

These developments have led invariably to an assumption that we are "done" with fossil fuels across the energy system, that there is no need for further development of new resources, and that we have to stop using them as soon as possible. This assumption has also led to a perception of "good" renewables-based technologies in global energy systems today, on the one hand, and "bad" fossil fuels-based technologies, on the other. The reality is that this debate is much more nuanced and requires more thorough investigation. Carbon capture and storage (CCS) technology and managing methane emissions throughout the fossil energy value chain can help meet ambitious C[O.sub.2] emission reduction targets, while fossil fuels remain part of the energy system. This will thereby allow fossil fuels to become "part of the solution", rather than remain "part of the problem". All technologies have a role to play in an energy system guided by rational economics.

Fossil fuels comprise 80 per cent of current global primary energy demand, and the energy system is the source of approximately two thirds of global C[O.sub.2] emissions. Inasmuch as methane and other short-lived climate pollutant emissions are believed to be severely underestimated, it is likely that energy production and use are the source of an even greater share of emissions. Further, much of the biomass fuels are currently used around the world in small scale heating and cooking. These are highly inefficient and polluting, especially for indoor air quality in many less-developed countries. Renewable biomass used in this way is a problem for sustainable development.

If current trends continue, in other words, if the current share of fossil fuels is maintained and energy demand nearly doubles by 2050, emissions will greatly surpass the...