According to a research team from the Energy Futures Lab and Grantham Institute for Climate Change at Imperial College London, the answer is a very clear yes. Not only that but it will cost only 1% of global GDP and it can be done with technologies which either currently exist at commercial scale, or which have been demonstrated at sub-commercial scale but which are still awaiting full-scale deployment.

A large part of the transformation, the report states, comes from deploying new technologies which save energy, avoid increasingly expensive fossil fuels, and in many cases are projected to fall in cost over time.

Interestingly, the report states that the globally-averaged CO2 intensity of electricity generation can be reduced from a projected level of around 500 g/kWh in 2050 to less than 100 g/kWh. Then much of the emissions reduction will flow from conversion of energy-using systems to electricity, accompanied by a switch to zero-carbon or near-zero-carbon generation technologies, including carbon capture and storage (CCS), nuclear and renewables.

There needs to be a shift towards electrification of industrial manufacturing processes, building heating systems, and vehicle propulsion systems. A range of technologies will be required to achieve this, including increased penetrations of electric arc furnaces in steelmaking, heat pumps in buildings, and battery electric and hybrid vehicles in road transport.

Energy efficiency will need to improve in order to achieve relatively low-cost CO2 reductions which will help keep the overall energy system transition cost manageable. As such, the authors envisage a 19% improvement in industrial energy efficiency, and a 33% improvement in both the transport and buildings sectors.

The world will need to shift from its current overwhelming reliance on fossil fuels (especially in transportation), although these will still be a significant part of the non-transportation 2050 energy mix. This decreasing reliance is important if we are concerned about uncertainty around future fossil fuel prices, or indeed about rising fossil fuel prices.

The report concludes that

• Without concerted action and a continuation of historic trends in energy usage,  global fossil fuel consumption will increase by 50% compared to current levels.
• Achieving a much lower level of CO2 emissions in 2050 (around 15 Gt per year, which is broadly consistent with a 2˚C global warming limit) will cost of the order 1% per year of  global GDP by 2050 in a low fossil fuel price case, and much less than this if fossil fuel prices are higher.
• Such a transition will require a broad range of low-carbon technologies deployed across all sectors of the economy, underpinned by the decarbonisation of the power sector, within which the precise mix of technologies does not affect the overall cost significantly. In each low-carbon scenario the unit electricity costs increase by about 40% (in the high fossil fuel price case) to about 70% (in the low fossil fuel price case)  compared to the low mitigation scenario, but even in the low carbon scenarios, electricity cost increases would not keep pace with increases in per capita GDP to 2050.
• As well as electricity decarbonisation, achieving energy efficiency across the whole economy is critical, with the reported low-carbon scenario showing an approximate 30% reduction in end-use energy demand in 2050, compared to the low mitigation scenario.
• In the low-carbon scenario, fossil fuel demand would reduce by almost 40% in 2050, compared to the low mitigation scenario.
• Every one of the ten [global] regions studied makes a significant contribution to the overall achievement of the low-carbon transition. [The authors] believe this transition to still be achievable and affordable.

GallonDaily remains unconvinced by some elements of the Imperial College low carbon scenario but is is encouraging to see at least one team of experts reporting that a 50% reduction in emissions by 2050 is still possible.

The full report is available by following a link from http://www3.imperial.ac.uk/climatechange/publications/collaborative/halving-global-co2-by-2050