Climate Change, Cars & Challenges

In the last three months I have presented at and/or been on panels to discuss transport, covid, the climate emergency and cars. Earlier in March 2021 the Rail Vision for the Cardiff Capital Region, which I helped prepare, was published; this follows Cardiff Council’s Transport White Paper in February 2020 (which I also helped prepare). 

To support some further upcoming events, I want to quickly summarise a big change that is coming and is unavoidable, re: car use….whether we like it or not… and I am going to try do this in a few bullet points!

I have also covered some of these details in recent slide sets (and at a Cardiff University Net Zero Infrastructure Event in June 2021) and several earlier blogs including:

A Public Transport Grid for the M4 Corridor… – Mark Barry ( 2020

Driverless cars as a service, batteries and urban spaces… – Mark Barry ( 2017

Covid19, Safe Spaces & Wellfield Road? – Mark Barry ( 2020

Corona Virus, Homeworking and Transport – Mark Barry ( 2020

But back to the bullets….

  • Climate Change is real, caused by humans and unless we start to make radical changes  – including and especially  our mobility choices (transport ranges from between 15~25% of total carbon emissions) we risk irrevocable damage to essential ecosystems. 

Figure 1 NASA Historic Atmospheric Carbon concentrations

  • At the moment (and pre-covid)  car mode share was on average over 80% with Public Transport (PT) and Active Trave (AT) in total less than 20%

Figure 2 Senedd Research – Mode Share

  • This is in stark contrast to the 1950s and earlier when car use was very much in the minority

Figure 3 Mode Share in UK 1950 – 2015


Most countries, including the  UK and Wales, now have legally binding decarbonisation targets in place. By 2029 Wales needs to have reduced carbon emission by 45% Vs 1990 baseline  and 80% by 2050.  By 2018 we had reduced by  just 29% Vs 1990 (some of that reduction is illusory and ignores “offshore” emissions) and transport in  Wales has reduced by a much smaller amount, just 4%; and in the EU overall its gone up!

Postscript (June 2021) and to re-iterate from the Wales Transport Strategy published earlier in 2021…

“The Welsh Government is committed to net zero-emissions by 2050. In 2018 transport was responsible for 17% of Welsh greenhouse gas emissions – 62% from private car use, 19% from Light Goods Vehicles and 16% from bus and Heavy Goods Vehicles.  The UK Climate Change Committee has proposed a carbon reduction pathway for surface transport that means that emissions need to be roughly halved between 2020 and 2030.”

This is consistent with the targets set out by the Advice Report: The Path to Net Zero – Wales, by the Climate Change Committee in December 2020 that requires a reduction in transport emission from 6 million to 3million MtCO2. – Figure 6.1

However, If the Paris Agreement’s international equity aim is taken seriously, the Tyndall Centre for Climate Change Research estimates that at 2017 emission levels, the entire Paris-compliant CO2 budget for the energy sector (inc. transport) is likely to be used up before 2030.

Climate scientists (ref Tyndall Centre)consider the above CCC carbon reduction pathway to fall short of meeting the “international equity” aim of the UN Paris Climate Agreement, and argue UK carbon budgets should be halved. For WG that means reducing transport emissions to ~1.5MtCO2 by 2030!

Figure 4 Welsh Government Decarbonisation Targets

Figure 5 WG Decarbonisation Performance….Transport lowest reductions!!

Figure 6 EU Emissions since 1990 by sector

Figure 6.1 CCC Sectoral emissions under the Balanced Net Zero Pathway for Wales

  • I should also add the destruction of local town high streets everywhere as a result of the growth of car based shed retail (especially food) and offices all over the country: Spytty Park, Culverhouse X, Trago Mills, Cyfarthfa Retail park, McArthur Glen, Cardiff Gate, Imperial Park, etc, etc and now the perversity of drive through coffee retail!

This recent paper from Todd Litman of the Victoria Transport Planning Institute is pretty clear in its conclusions re car use externalities.

The Welsh Government also recently commissioned a report by the Foundational Economy Research, “Small Towns Big Issues” which illuminates the negative impact of out of town car based development – especially on existing town centres.

  • Furthermore, cars spend perhaps 95% of their time doing nothing –  so huge, embedded carbon costs and a grossly irresponsible and inefficient use of scare natural resources!

Figure 7 Credit: Ellen Macarthur Foundation

  • In particular, the phenomenon of induced demand (which is poorly understood including by me until recently) means that unless we introduce demand management measures,  all roads will fill up some of the time.  You can’t remove congestion…you can only move it around!  This video is a good explainer; building more road space generates more traffic.  The DfT also commissioned a review of the academic literature related to induced demand in 2018. In reality its only 20-30% of peak time traffic that cause 100% of congestion on the M4 example. It is overwhelming clear that we should invest to provide a PT alternative for that 20-30% and price the road to ensure it operates more effectively for those that still need to use it. We really do have more than enough road space!

PS Nov 2022 – I have also prepared a brief video to try and explain the phenomenon of induced demand – with reference to the M4 in southern Wales

Post script. This recent article in City Commentary from Portland by Joe Cortright is very insightful re how road pricing reduces congestion….as is the following graphic originally drawn by a Walter Kulash.

Figure 8 What sort of future do we want? (I 405 in Los Angeles)

  • Now we are facing a car industry greenwash with EVs that are still poorly utilised,  getting bigger and heavier (so requiring more energy to move) and  often “sold”  under lease arrangements  that try to persuade us  to replace with new every 2 or 3 years.

  • Before we electrify our car ecosystem, we need fewer and smaller cars first….and greater utilisation of vehicles through sharing. We also need to keep an eye on innovation…for example solid state batteries and especially small, fast swap modular batteries and battery stations. The idea we are all going to be trailing cables through our front room windows to charge millions of stationary cars using 240V domestic supply is, well, crazy!

Post Script: Worth a look at these…

Sun Mobility EV: Sun Mobility to set up 100 EV battery swapping stations across Bengaluru – The Economic Times (

Startup Ample Working on 10-Minute Electric Car Battery Swapping (

(2) China’s NIO Cuts EV Charging Time With Battery Swapping Technology – YouTube

Check Out A Geely One-Minute EV Battery Swapping Station In China (

Figure 9 – Credit: Anthony Simpson

Figure 10 We are turning cars into mobile phones with wheels!

Figure 11 EU Transport Emissions

To hit the decarbonisation targets in respect of transport, I assert we need to increase public transport mode share from less than 20% today, to  over 40%,  and reduce car use from 80% to less than 40%;  with at least 20% AT (even more in urban areas).  This means:

  • At least  3 times more Public Transport capacity

  • Demand management measure  – fiscal (yes and including road pricing! or as I prefer to call it “a reduction in the car use discount”)  and physical  measures; so less space for cars, especially in urban areas & less volume parking provision in town and city centres, hospitals, retail parks, etc (and certainly not “free parking” which actually encourages more car use)

  • More flexible working (combination of HQ, local hub and home working). I did a brief blog on this at the beginning of the lockdown last April.

  • A planning revolution to encourage more PT/AT connected city and town centre development and the gradual relocation of all our car based out of town stuff (especially shed food retail, public services, offices, etc) back to town and city centres. I also have written a little on Transit Oriented Development (TOD) in the past.

For Cardiff,  the CCR and WG, the Public Transport strategy and vision is getting clearer, and through  Transport for Wales some of it is being delivered through the next phase of the “South Wales Metro”.

  • Cardiff Council Transport White Paper, including…
    • Cardiff Crossrail and Bus Rapid Transit
    • More  Active Travel and especially segregated cycle routes
    • Schemes to limit car access in urban areas (so removing private vehicles from Castle Street for example and reduced access in places like Wellfield Rd)

Figure 12 Mobility priorities set out in Wales Transport Strategy March 2021

Figure 13 Illustration of possible next phase of Metro  to be operating by 2024

Figure 14 CCR Rail Vision (March 2021) – Key Interventions Summary

Figure 15 Cardiff Council Transport White Paper – Vision (February 2020)

However, there are still major challenges for government to navigate, including:

  • Developing a new methodology for transport planning and demand modelling that reflects the decarbonisation targets – based on “Define and Provide” instead of “Predict and Provide”

Post Script Oct 2021: Given the non-devolved status of NR’s rail, this will required a single joint WG/UK Government programme that covers decarbonisation, transport investment and levelling up, requiring a total capital investment of perhaps £4Bn over 10-15 years. This could be split 50/50 between WG and UK Government, with UK Gov contributing to the enhancement of the NR Rail network for which they are responsible and WG to cover further CVL enhancement, bus/BRT and Active Travel

  • Developing and implementing “road pricing” and other demand management measures – this is fundamental, fair and necessary (see the link below to my blog on the radical fiscal measures our economy needs) if we are to start living in balance with nature. Aside from a direct HMT tax, (which WG would not control) as is the case now, we should also consider WG proxies; for example high car parking charges (via business rates?) for out of town retail, offices, hospitals, etc

  • Ensuring Transit Oriented Development is adopted all over Wales and is linked to town and city centre regeneration. This has to include measures that over the next ten years encourage the relocation of offices, retail, etc from places one can only access in a car to PT connected places and town, city centres.

Figure 16 – “Define and Provide” Transport Planning and Demand Modelling

That’s it really.…we need to make some major changes….and soon!

For those still interested, I have also penned some thoughts re the radical fiscal overhaul our economy needs

Example References:

2021, Cardiff Capital Region, “CCR Rail Passenger Vision”

2020, Cardiff Council, “Transport White Paper

2021, Welsh Government, “Llwbyr Newydd: Wales Transport Strategy

2020, Climate Change Committee, “Advice Report: The Path to a Net Zero Wales

2021, Todd Litman, Victoria Transport Planning Institute, “The Business Case for Post-Covid Public Transit”

2021, WG Foundational Economy Independent Research, “Small Towns, Big Issues: aligning business models, organisation, imagination”

2018, UK Gov Department of Transport (WSP and Rand Europe), “Latest Evidence on Induced Travel Demand: An Evidence Review”

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