What are embedded or embodied emissions?
Embedded emissions is a broad term used to describe the range of greenhouse gases (GHG) emissions associated with the production of a product (or an infrastructure project).
For instance, whilst a carbon footprint can be used to express the carbon of running a car, embodied carbon would tell you the carbon footprint of producing a car
Embodied carbon calculations therefore require an understanding of all of the materials, or ingredients, within a product or project, and all activities related to those materials, such as processing and transport.
When deciding whether an infrastructure project or transport policy contributes to or mitigates against global warming, we must compare the amount of energy used by the vehicles and infrastructure to the amount of energy consumed in producing it.
Embodied energy is an accounting method which aims to find the sum total of the energy necessary for an entire product life-cycle. Determining what constitutes this life-cycle includes assessing the relevance and extent of energy into raw material extraction, transport, manufacture, assembly, installation, disassembly, deconstruction and/or decomposition as well as human and secondary resources.
This graphic by Dr Elliot Fishman represents the carbon footprint of various modes of transport. But it also illustrates how the top of the range electric vehicle, run on ‘green power’, has been given the same carbon ranking as walking and cycling . This is how we have been sold the ‘zero-emission’ myth of electric vehicles. No account has been taken of the embodied greenhouse emissions in the production of the vehicle. This is an anomaly that needs to be rectified..
Why is this important?
In 2017 the United Nations Environment Program (UNEP) reported that we are not on the right trajectory to hit carbon targets. This means we will need to reach peak emissions by 2020 and close the emissions gap by 2030,
This graphic shows how the longer we continue to put off change, the more extreme policy will need to be in the future.
The absolute imperative is to cut energy use at the same time as switching to renewables. At present we are significantly behind the curve and worryingly greenhouse gases actually increased in 2017.
As the squeeze on the carbon budget becomes tighter, we must scrutinise and prioritise policy and infrastructure that will help us reduce energy use quickly. We must align to the facts, not what is convenient.
Upfront investment in producing infrastructure and vehicles is the most immediate and often the largest part of the carbon expenditure. This is why I want to know how the Mayor of London and Transport for London are accounting for all greenhouse emissions in the Mayor’s Transport Strategy.
I will be submitting Freedom of information (FOI) requests for embedded carbon emissions in a wide range of infrastructure projects such as The Elizabeth Line and the Silvertown Tunnel. As well as vehicles such as ZEC Taxis and Low emission buses. I look forward to updating you on my progress.