The UK is facing an energy challenge: how do we achieve an 80% cut in our carbon emissions by 2050, while maintaining a secure supply of energy at an affordable price?
Part of my role as Chief Scientific Advisor for the Department of Energy and Climate Change is to address this challenge by helping to drive forward a plan to meet our climate change targets in 2020 and 2050. It is crucial that decisions to achieve these targets are based on scientific evidence.
So what does the evidence tell us? According to various projections including those from the Committee on Climate Change (CCC), if we are to meet our future carbon targets, the UK’s energy supplies should be mostly made up of gas, nuclear, and wind in 2030. Most notable is that gas will continue to play a central role in our energy mix in the coming decades, particularly as we move away from coal for electricity generation. Last month, the Secretary of State highlighted our commitment to phase-out coal by aiming to make the UK the first developed country to take coal off the system by 2025.
Perhaps the greatest challenge to meeting our long-term emissions target is decarbonising our heating system. Heating accounts for 45% of all energy use in the UK, with the majority used for cooking, and to warm our homes and our water . This has resulted in the UK having one of the most extensive gas grids and largest gas boiler markets in the world.
If we are to decarbonise our heating system, low carbon heating technologies need to be as effective as traditional fossil-fuel options in meeting our needs. UK households are used to relatively user-friendly and rapid response boiler based heating systems. Therefore, alongside challenges faced in integrating low carbon solutions within the energy system, they must also meet our needs in terms of cost, scale of disruption, and value delivered.
While we work to increase our low-carbon energy capacity, it is clear we will need gas in the short to medium term. Since 2004, the UK has been a net importer of gas due to the rapid decline of production from the UK Continental Shelf. We are currently importing more than 50% of our gas, with this projected to increase to 75% in 2030 . Importing liquid natural gas is generally more carbon intensive than producing our own home-grown supplies .
One possible indigenous source of gas is from UK shale reserves using the process known as hydraulic fracturing, or fracking. “Conventional” gas - reserves (such as in the North Sea) are contained in permeable rocks, such as sandstone, and therefore readily flow to the surface when a well is drilled. Shale gas is essentially the same as North Sea gas (i.e. methane) but is trapped in impermeable shale rock. Creating fractures in the rock by fracking enables shale gas to flow.
While some people are concerned about the safety of this procedure, the evidence shows that the shale gas industry can be taken forward safely. Reports by the Royal Society and Royal Academy of Engineering, and Public Health England all conclude that risks can be safely managed, with best practice enforced through regulation. The UK has more than 50 years’ experience regulating the onshore oil and gas industry, and additional measures implemented through the Infrastructure Act are in place to ensure stringent safety controls.
Shale gas has the potential to reduce our reliance on imported gas; however, we do not yet know the full scale of the UK’s shale resources nor how much can be extracted technically or economically. The British Geological Survey estimates there could be a shale gas resource in the Bowland-Hodder basin (under Northern England) of anything between 822 - 2281 trillion cubic feet, compared to current UK annual gas consumption of around 2.5 tcf. We need more data before we can determine the viability of this industry as not enough is yet known about how much gas may be ultimately produced. Industry needs to conduct exploratory drilling and fracturing before these factors can be estimated.
Securing the UK’s energy future remains one of our biggest challenges. We need to explore avenues to clean energy based on the evidence we have, which shows that gas will play a role in years to come. We must explore the role of shale gas in our wider energy mix alongside new nuclear capacity and wind projects if we are to address this challenge.
 Infrastructure and in a low carbon energy system to 2030 – Carbon Capture and Storage Final Report for the Committee on Climate Change – Element Energy Limited, July 2013
 Energy Consumption in the UK, 2014
 DECC, UK Oil and Gas Production Projections, March 2015
 Potential Greenhouse Gas Emissions Associated with Shale Gas Extraction and Use, Mackay-Stone, September 2013