Better modelling for the energy mix

Contrary to Haewon McJeon and colleagues' implications (Nature 514, 482–485; 2014), natural shale gas and renewables are not necessarily competitors. They are driven by different policies and markets.

Over the next decade or so, natural gas can reduce coal consumption and can be rapidly dispatched to balance the intermittency of energy from wind and solar sources. In the longer term, say over the next 50 years, this mix can provide a path to an affordable, low-carbon energy system, especially if it is configured as a backup or coupled with energy storage.

The low capital and high operating costs for natural gas combine well with the high capital and low operating costs of wind and solar. And by reducing the cost of climate mitigation, natural gas should motivate more-aggressive climate policies by governments. Gas is therefore promising because it is a powerful climate-mitigation option, not because it will prevent climate change in the absence of policy.

Moreover, the decisions that shape global energy choices are not always economic or technical (see B. K. Sovacool Nature 511, 529–530; 2014). Effective modelling needs to capture all of the complex and often non-quantitative forces that determine outcomes. These include energy security, trade policy, social equity, weather, distribution of resources, dynamic policies and unforeseen technological advances. Without these factors, the reliability of the long-term forecasts from McJeon et al. seems low.