Achieving a low carbon world will require radical changes to day to day infrastructure such as transport, energy and water, leading engineers have said in a think-piece report published today.
Use of infrastructure, such as roads and rail, contributes a significant proportion of the UK’s carbon emissions – over 50 percent of total emissions coming from the use of transport and energy supply alone. The Institution of Civil Engineers (ICE) says in its report Building a Sustainable Future that a truly low carbon world will require a major rethink into the way we plan, design, construct and use infrastructure assets, making carbon a key determining factor alongside performance factors such as social benefits and cost. It says that in many cases low carbon innovations will also improve services for the public.
The report, a response to a challenge by the Government’s Chief Construction Adviser Paul Morrell, says this requires a whole-life approach to carbon assessment, not solely assessing the carbon used in construction but balancing this with the carbon used during the operational lifespan as well. This would help to identify the most carbon efficient option in the long-term.
In the case of the roads network – which accounts for 93 percent of domestic transport sector emissions – this would mean considering the carbon emitted by vehicles using the road over its lifetime and finding ways to drive it down through innovative design choices. The report notes that fossil fuelled vehicles use more energy and therefore emit more carbon when they are forced to stop and start frequently, so making roads as free flowing as possible would have a significant impact on emissions. At the same time this would improve the economic and social performance of the asset by reducing congestion and travel times which have a detrimental impact on the economy (footnote 1).
An example could be replacing roundabouts or traffic lights on the most heavily trafficked routes with grade-separated junctions that divert turning traffic using over-bridges, allowing all other vehicles to continue uninterrupted. Likewise more energy is required to power a vehicle uphill than along a flat road, so leveling the gradient of roads would also reduce emissions.
Although achieving this type of ‘low carbon’ road would require an upfront carbon and financial investment, it would be ‘paid back’ over its operational lifetime by the carbon saved from vehicle emissions as well as the economic benefits of a more efficient roads network (footnote 2).
Chair of the report working group Tim Chapman said: "We really need to challenge current thinking if we are to reduce emissions from infrastructure on the scale needed. Roundabouts, traffic lights, steep gradients and other features that require vehicle engines to work harder all exacerbate carbon emissions. It’s time we looked at addressing these ‘carbon pinch points’ on major routes where a combination of relatively small, targeted interventions could make significant long-term carbon savings and improve the performance both socially and economically of vital infrastructure assets."
The report also identifies carbon pinch points in other core infrastructure networks. In the water system it suggests that alternatives could be sought to energy-intensive waste water treatment processes and water pumping stations, and on the rail network it highlights the need to progressively electrify the main routes.
It stresses however that simply building new, and improving existing infrastructure won’t be enough. "Reducing the number of users and the associated congestion at peak times will be crucial to manage increasing demand. We need to explore if and how peoples’ road usage could be better managed – perhaps by introducing a range of tariffs for different times of the day with higher fares for peak time journeys or even considering a system similar to rail travel where passengers are required to ‘book’ their car travel using emerging new technologies. User tariffs have been unpopular, partially because they have been seen as a new tax but also because the benefits haven’t been explained – most people would like their journeys to be more reliable and these new technologies can make that happen."
ICE hopes the second National Infrastructure Plan, due this month, will establish the platform for deeper change by outlining performance measures for critical infrastructure networks and providing a long-term vision of infrastructure development that minimises carbon in the UK.
Download the full report here www.ice.org.uk/lowcarbonreport