Thursday, January 30, 2020


Should we be doing more to limit our trade with China, if we are serious about having a global effect on emissions rather than concentrating on purely domestic issues?
[Third in a series originating in a set of questions put by sixth form students. 
I should also thank Environmental Change Institute colleagues. 
Their ideas have inspired a number of my comments.]

Trade and climate connections are many, so a full answer has several dimensions. They relate to the amount of CO2 emissions embedded in the manufactured goods we process, to comparison of manufacturing methods and energy policies in different countries, to fuel use in shipping, to the international norms that govern trade, and potentially to the enforcement, if any, of international agreements.  

In the current international system of accounting for greenhouse gas emissions, they are generally attributed to the country where they enter the atmosphere, regardless of where any final products go.  This limits our understanding of the full impacts of our own national consumption.  One illustration is the apparently very substantial reduction in UK emissions since 1990. Closer examination reveals this was due, not just to the coal to gas transition or the growth in renewable energy, but in large measure to the de-industrialisation of the UK in the 1980s and 1990s under the Thatcher government. In other words since 1990 the UK has exported much of its manufacturing industry and the CO2 emissions that went with it. The reduction in our carbon footprint is less than we occasionally pretend.

So it is sensible to look beyond the patterns of energy use within the UK, as well as beyond our own personal choices within the home and in personal travel. There will be an embedded carbon footprint in all the goods and services we purchase. If we all reduced our consumption of manufactured goods, but especially those that have a high carbon content, then that would certainly be an important impact. It is not always easy to tell which are the worst industries in causing emissions, but one recent report by the World Bank has claimed that the fashion industry is responsible for 10% of global emissions, more than aviation and shipping combined.

 Policies on trade

 It’s almost impossible for individual consumers to make meaningful calculations of the carbon footprint of different products, but we can collectively make sensible choices through trade policy. It will be important to trade with countries that have strong environmental policies and are willing to take action on reducing emissions, and setting meaningful targets, like the European Union. Goods produced in those countries will, over time, tend to have a significantly lower carbon footprint than others, especially as their emissions reduction policies start to bear fruit.

Those policies are now starting to impact on, and create tensions for, trade policy. As the EU seeks to avoid simply exporting its own manufacturing to countries with less commitment to reducing emissions, it is proposing measures that will ultimately amount to a carbon adjustment tax at the border, for countries that are not part of the EU’s own ambitious emissions reduction programme. We should expect to see this, and its reconciliation with WTO rules on trade, as a major source of controversy over the next few years.

And imports from China?

However most of the UK’s international imports (and their embodied carbon) are not from China.[2]  China accounts for only about 7% of UK imports, about the same as France but with a higher proportion of manufactures, and significantly less than the USA and Germany at about 11% each. A further complication is that the carbon footprint of your purchase will depend on how what you are buying is manufactured in China, and whether the process there results in more or less carbon emissions than it would if you were buying a similar product from somewhere else. 

But we should be careful not to overstate the negative impact of China on our carbon footprint. China currently has a very high share of the world's manufacturing and the emissions that go alongside; and they also have what is almost certainly an excessive amount of coal-fired capacity, much of which is under-utilised and may eventually be retired early. On the other hand they have also been very active in developing and promoting low carbon technologies, including wind, solar and nuclear. And they are themselves very vulnerable to climate change so they have some strong incentives to improve. 
Shanghai, 2011. Coal barges on the Yangtse.

China has other emissions problems, particularly with city air pollution.  The Chinese city of Shenzhen, with a population similar to London, has 17,000 electric buses (in part to improve air quality), whereas London has 200.  In terms of emissions generated per head of population, China ranks well below Saudi Arabia, Australia, the United States and many other countries, although surprisingly it is above France.

Does distance matter?

Surprisingly, and although shipping is a significant contributor to global emissions, the carbon footprint of the freight involved in trade will be a small part of the total and will usually be less important than the footprint involved in manufacture. Other things being equal it makes sense to trade with your neighbours, but other than for obvious bulk items or sometimes for lower value perishable items where air freight is involved, the distance to market will not usually be a critical factor.
Benito Mueller gives an interesting example.[3]  “According to DfID, … the emissions produced by growing flowers in Kenya and flying them to the UK can be less than a fifth of those grown in heated and lighted greenhouses in Holland.”
But emissions from freight and food miles are topics for another day.

And the lessons from this analysis?

The carbon footprint of the manufactured goods we buy does matter.
“Fast fashion” accounts for a surprisingly high proportion of global emissions.
We cannot avoid the connections between climate-related issues and trade policy.
China accounts for quite a small proportion of our total imports.
Distance will usually be less important than the carbon content of the means of production in different countries. Food miles will not always be a good indicator of environmental credentials..

[1] I have not so far found an authoritative estimate of the contribution of motor manufacturing, but its contribution appears to be less than 10%, although it is clearly one of the larger contributors.
[2] Parliamentary research briefing. Number 7379, 5 November 2019. Statistics on UK trade with China.

[3] Food Miles or Poverty Eradication: The moral duty to eat African strawberries at Christmas. Benito Mueller. Oxford Energy and Environment Comment. October 2007.

Wednesday, January 29, 2020


Or is it just a case of making us feel like we're doing something to help? (A second big question inspired by school sixth form students.)

Use your voice, use your vote, use your choice.” (Al Gore)

The first point to make is that any early action on reducing CO2 emissions should be considered as having a high per unit premium value for the emissions saved.  Early reduction is more valuable than future savings in terms of postponing key climate milestones.[1]  This delay provides more time to develop options both in finding better means to reduce emissions, and in coping with the consequences of climate change as it develops.  Individual actions have the particular advantage that they can have some effect quickly and immediately, whereas government policies and international agreements tend to take much longer to come into effect.

The more difficult question is what kinds of changes people will make, including changes in lifestyles, are plausible, how large they are, and how many people are going to engage with them. This is in large measure a question about how significant changes come about, both in the very general terms of culture and lifestyle, and in social and behavioural norms.

A few years ago a BBC reporter was persuaded to try the experiment of becoming Ethical Man[2], to determine what savings he, with his family, could make, but these were to be within the bounds of credible change and broadly keeping to his familiar lifestyle. He almost certainly went further than most people will be prepared to (giving up his car for example), but it was estimated that they had cut their carbon footprint by about 20%, and up to 50% in terms of directly controlled energy use for normal household purposes and travel. So it is fairly easy to show that some significant reductions are possible without fundamental and systemic change. But will sufficient numbers of people be persuaded?

Many say we should drive less, fly less, eat less meat. But others argue that personal actions like this are a pointless drop in the ocean when set against the huge systemic changes that are required … a single person’s contribution is basically irrelevant (much like a single vote in an election). But my research … has found that doing something bold like giving up flying can have a wider knock-on effect by influencing others and shifting what’s viewed as “normal”.  [Steve Westlake in The Conversation.] [3]

Communication is critical.  If one individual starts cycling to work, or eating less meat, or taking a shower instead of a bath, then the impact is minimal. But social interactions with friends, relatives and colleagues can over time change behaviour much more widely. The Westlake article suggests the effects can be dramatic.

In a survey I conducted, half of the respondents who knew someone who has given up flying because of climate change said they fly less because of this example. That alone seemed pretty impressive to me. Furthermore, around three quarters said it had changed their attitudes towards flying and climate change in some way. These effects were increased if a high-profile person had given up flying, such as an academic or someone in the public eye. In this case, around two thirds said they fly less because of this person, and only 7% said it has not affected their attitudes.

I wondered if these impressionable people were already behaving like squeaky-clean environmentalists, but the figures suggested not. The survey respondents fly considerably more than average, meaning they have plenty of potential to fly less because of someone else’s example.

Some social psychology research suggests that strongly held positions held by sufficiently large minorities can lead quite quickly to a change in what is seen as the consensus position or as normal behaviour. It is quite possible that we are currently in the process of reaching that critical mass in popular appreciation of the threats of climate change. Scientists have been warning about climate change in no uncertain terms for at least the last 30 years, but the shift to a position where a majority in developed countries see it as the greatest threat to themselves and their children has been comparatively recent. However it is difficult to say how much of that shift is attributable to dramatic climate or weather related events (such as the Australian bush fires), how much to awareness promoted by wildlife programmes (David Attenborough) and the media attention attracted by activists such as Greta Thunberg, and how much to the gradually increasing willingness of people to talk about the subject with their friends.

If people are seeking to influence others then avoiding the charge of hypocrisy is important. Very few things are less impressive than some celebrity taking a private jet to a conference to argue for everyone else to change their lifestyles. So that provides another strand to the case for individual action, at least if you want to have an influence on others.

Overall it is clear that individual actions can make a difference. But of course they are by no means sufficient to meet what is needed. That will only come about through much more far reaching and systemic changes which depend not just on personal initiatives but on major infrastructure investment and innovation. The other effective actions that individuals can take is to “use their vote”, demand that their elected representatives support effective action, and use their influence as consumers to put similar pressure on business – much of which is already starting to get the message.

[1] The arguments are presented more fully on another page, Cumulative Carbon (button on bar at top of page):

Saturday, January 25, 2020


 What is the single biggest thing an individual can do to reduce their carbon footprint?

An ECI colleague was recently asked to give a short overview of renewable energy and climate change issues to school sixth form students. They presented in advance a dozen quite interesting and difficult questions, to which a number of colleagues contributed suggested answers. It was a smart set of questions and the answers may be of interest to a lot of adults too. So in my next few postings I intend to summarise some of our collective wisdom. This is the first of those questions.

The English writer Sydney Smith: “It is the greatest of all mistakes to do nothing because you can only do little. Do something.”

Al Gore: “Use your voice, use your vote, use your choice.”

The above quotes raise some profound questions to which I hope to return, but let’s start with the simple question of personal carbon footprint. The answer may be very different for different people, as no two people start from the same position, have the same tastes or have the same opportunities. For example if you are a vegetarian, cutting down on meat is no longer an opportunity for you to make further reductions. And if you always go on local cycling holidays, there is no point suggesting you cut down on your flights. Similarly your daily transport choices will depend on where you live. So the right answer is to work out what is best for you, consider the biggest impacts of your own lifestyle, and prioritise what things you want to change. The most significant personal reductions are likely to come from food, travel choices, home energy use (especially heating); and consumer products, so I'm going to make several different suggestions. None of these incidentally are intended to make your life a misery or imply return to some pre-industrial fantasy world. Nor do most of them require expensive investments. But they are intended to be about a more clever use of resources.

Eating less meat is potentially one of the biggest ways to reduce our carbon footprint. The calculations suggest that beef has a higher footprint than pork, which is higher than chicken. Of course reducing food waste and excessive packaging is helpful too.

If you are already vegetarian and fly a lot for holidays, then fewer long-haul flights will mean a pretty large reduction in your carbon footprint. Driving, especially when with passengers, is a lot better than flying, if you have the time and inclination. Taking the train is better still. If you are using a petrol or diesel car, we can note that the biggest sources of excess fuel use are generally taken to be speed and congestion.

If we turn to other everyday activities then there a lot of small savings that people can make. But it’s worth bearing in mind that one of the biggest consumptions of energy in the home is for heating. Turning your domestic heating down by one degree C, if you can do so without discomfort, has been estimated to reduce consumption by up to 10%. Not heating the house when you are not at home will help too. And if your house still has an old-fashioned gas boiler then you should convert to a condensing boiler as soon as possible. It can cut your bills and your carbon footprint for heating by up to a third. Last but not least, there may be some major savings to be achieved by reducing the heat loss in your home, draught-stripping of windows and home insulation (if you have’nt already applied these measures).

Of the other substantial energy uses in the home the next most important are in the kitchen – cooking and refrigeration. Obviously there are small easy changes you can make which will reduce consumption, like making sure your refrigerator is not set too cold, or not over-filling your kettle. But when you come to change your appliances, pay attention to their energy efficiency ratings.

Still in the home, another simple but substantial energy saving is switching to LED lightbulbs. The energy saving compared to old -fashioned incandescent bulbs is over 80%. Again it is a simple step which both saves money and reduces your carbon footprint.

Finally there is the indirect impact of the energy and carbon emissions associated with the various consumer goods we buy. If we all reduced our consumption of manufactured goods, but especially those that have a high carbon content, then that would certainly be an important impact. This is a much more complex and contentious subject and I hope to address this and related issues in later postings. It is not always easy to tell which are the worst industries in causing emissions, but one recent report by the World Bank has claimed that the fashion industry is responsible for 10% of global emissions, more than aviation and shipping combined.

You should expect to see more public discussion on this in the future.


However the next question will be: Do individual actions have an impact or do they just help us feel good?

Wednesday, January 15, 2020


From the pure doctrines of neoliberal thinking the intellectual pendulum has been moving back from market fundamentalism towards more ambivalent and centrist positions on the role of policy interventions by the state. Nowhere is this more true than in the vitally important power sector and its pivotal position in addressing climate issues. A major review from within the World Bank confirms this trend.

The phrase Washington Consensus was first used in 1989 by the economist John Williamson to describe prescriptions on policies for macroeconomic stabilization, opening of markets to trade and investment, and the expansion of market forces within domestic economies. Subsequently, and to his dismay, it was given a wider meaning, to refer to a more general orientation towards a strongly market-based approach (sometimes described as market fundamentalism or neoliberalism). The distinction is huge, and Williamson has argued  that his original, narrowly defined prescription is now  broadly taken for granted, enjoying the status of "motherhood and apple pie", but that the broader meaning, as a kind of neoliberal manifesto, "never enjoyed a consensus in Washington or anywhere much else" and can reasonably be said to be dead.[1]

We are now seeing the gradual but measurable decline in influence of the more fundamentalist market philosophies that have dominated the last 30 to 40 years. For much of that time, the power sector, long a natural monopoly, has been in the nature of a laboratory for market-centric philosophies. A  main obsession of policy makers in the power sector has therefore been pursuit of a so-called market liberalisation agenda. Nowhere was this more prevalent than in major international institutions. These included the Energy Directorate of the Commission of the European Union, in its vision for a single integrated European energy market, and the World Bank, in its prescriptions for developing countries. The prescriptions were often strongly influenced by what came to be known, perhaps inaccurately, as the Washington Consensus. For electric power this meant several key characteristics:

·         vertical and horizontal unbundling of what were often fully integrated utilities; corporate separation of generation from the wires businesses of the transmission (high voltage) and distribution (low voltage) networks, and also from retail supply, and also division into multiple entities in generation and distribution.
·         the establishment of an independent regulator for the sector, and formal regulation of the residual elements of natural monopoly.
·         privatisation of all the unbundled entities.
·         ensuring the maximum of competition in all aspects of the sector, but particularly in generation and supply.

Paradoxically for an industry that had always, due to its combination of economies of scale and real time command and control, been regarded as a natural monopoly, reforms to open up the sector also became something of an icon for free market enthusiasts. If this industry could be converted to a collection of markets then anything was possible.

Progress in Europe

The UK had led the way when it came to reform. In 1990 the UK wholesale market was deregulated, competition was promoted and the industry was privatised. The European Commission enthusiastically encouraged other EU countries to follow this lead and liberalise their electricity markets. This was the dominant direction of travel, even if progress was both slow and partial. In France, in particular, the market is dominated by state-owned nuclear power, has a single transmission and a single distribution company, and remains one of the most successful power sectors in Europe, as is indicated by the comparative price figures shown below.

Meanwhile the UK, after attaining something close to theoretical perfection by the late 1990s, has, over the last 10 to 15 years, abandoned a number of the basic tenets of the fundamentalist philosophy. Government has intervened both through the introduction of price caps[2] and by making major decisions on, as well as underwriting of, new investment in generating capacity. Unsurprisingly leading free market enthusiasts such as Carlo Stagnaro[3] now write that “…in the EU, and the UK in particular, the liberalisation of the electricity market is rapidly being reversed and replaced by old-fashioned command-and-control policies.”

There are a number of good (as well as less good) reasons for this dramatic shift in policy direction.[4] An important one is the increasing emphasis on policy for reducing CO2 emissions, where the EU’s emissions trading scheme (ETS) has proved inadequate to the task of generating realistic carbon prices consistent with ambitious emission reduction policies. Another is the intrinsic failure of liberalised market structures to provide the incentives necessary to induce new investment in long life generation assets. A third is a failure to adapt spot markets designed by and for fossil generation plant operators as they become increasingly unworkable in a world dominated by the technical characteristics of renewables, nuclear and energy storage. A fourth is that even in its most liberalised form the power market has always retained significant elements of command and control, as well as a significant and complex role for the network operators who remain as natural monopolies.  And, finally, competitive retail markets, where they exist, have not delivered significant benefits to consumers and do not command widespread public approval.

But the bottom line is that the paradigm of energy markets free of significant intervention has been quietly dropped. Certainly, privatisation of the monopoly network components of the sector, with effective regulation, has brought some efficiency gains. But governments have also recognised their continuing responsibility for maintaining reliable and sustainable supply. In the UK there has been a dawning realisation of the need to reverse direction and head downhill from the sunlit uplands of the reform purists, and will shortly see it meeting an EU still struggling half-heartedly towards the summit.

And in developing economies? A recent ESMAP[5]  (World Bank) review suggests a major loss of faith in the Washington Consensus.

In the home of the Washington Consensus, the World Bank has long been attempting to improve power sector governance in developing countries, often using the liberalised market paradigm as an ideal. The typical underlying problems in much of the developing world are well known. They include arbitrary and inconsistent political interference in the sector, inadequate cost recovery (which in turn limits funds available for investment), and managerial inefficiency in state monopolies. World Bank prescriptions invariably contain many sensible proposals to remedy these problems, but they also pushed the comprehensive free market agenda far too hard in a sector that had always been recognised as one of the most difficult in which to create a genuine and effective competitive market. The  results were predictable. An extremely valuable recent review[6]  by ESMAP reviewed experience across a wide range of countries. The lessons are revealing. 

Only one in five countries implemented both vertical and horizontal unbundling of utilities, separating generation transmission and transmission from distribution and creating multiple generation and distribution utilities. Restructuring is intended primarily as a stepping stone to deeper reforms, and countries that went no further tended not to see significant impacts. Indeed, restructuring of power systems that are very small and/or poorly governed … can actually be counter-productive by reducing the scale of operation and increasing its complexity.

Only one in five developing countries has been able to introduce a wholesale power market during the past 25 years. … A demanding list of structural, financial, and regulatory preconditions for power markets prevents most other developing countries from following suit.

Many countries announced reforms that did not subsequently go through, and some countries enacted reforms that later had to be reversed.

Although many countries enacted solid legal frameworks, the practice of regulation continues to lag far behind. For example, while almost all countries give the regulators legal authority on the critical issue of determining tariffs, this authority is routinely overruled by the governments in one out of three countries. … cost recovery remains an elusive goal.

Among the best-performing power sec­tors in the developing world are some that fully implemented market-oriented reforms, as well as others that retained a domi­nant and competent state-owned utility guided by strong policy mandates, combined with a more gradualist and targeted role for the private sector.

Where distribution utilities were privatized, countries were much more likely to adhere to cost-recovery tariffs. This however is a confusion of cause and effect. It will normally only be possible to persuade private investors to participate if financial viability has already been guaranteed by tariff reforms. Requiring a newly privatised business to implement tariff reforms will tend to discredit the private sector by blaming it for higher prices. 

Market reforms can be helpful in improving the overall efficiency and financial viability of the power sector, and in creating a better climate for investment. However, they cannot—in and of themselves—deliver on these social and environmental aspirations. Complementary policy measures are needed to direct and incentivize the specific investments that are needed.

This is a complex and revealing story of modest successes and disappointing failures. The theoretical ideals of unfettered competitive markets and minimal state involvement have proved to be less important than much more basic goals of good governance, limiting arbitrary political interference and patronage, introducing cost covering tariffs and improving revenue collection (eg by reducing illegal abstraction). Much of this depended simply on making power sector entities into commercial organisations rather than organs of government.  All these basic reforms were in any case preconditions for the success of more ambitious targets, such as privatisation or functioning spot markets for energy trading. And developing countries will be under international pressures to face the same policy challenges as the developed world in terms of sustainability; this will continue to limit the scope for “hands off” policies for the energy sector.

The Way Ahead

To a very large extent the power sector is the future of low carbon energy provision, and its organisation is therefore a vitally important matter to everyone. The “Washington Consensus” will have had some notable achievements in promoting independent regulation, transparency, formal separation from government and a more commercial approach. But the more ambitious aspirations, for pure market structures free of policy interventions, have remained out of reach. The central importance of the sector, especially in the context of sustainable policies to address the issues of climate change, mean that governments are increasingly likely to play a major role in monitoring and supporting low carbon policies for the power sector.

[1] This summary paraphrases a Wikipedia article on this subject which also references Williamson’s observations on the subject.
[3] Stagnaro  is a Senior Fellow of the Italian free market think tank Istituto Bruno Leoni. His comments can be found in a 2016 article Whatever happened to electricity market liberalisation?
[4] A much fuller discussion of these issues can be found using the tab LOW CARBON POWER on the top bar
[5] The Energy Sector Management Assistance Programme of the World Bank. “ESMAP is a partnership between the World Bank Group and 18 partners to help low and middle-income countries reduce poverty and boost growth, through environmentally sustainable energy solutions. ESMAP’s analytical and advisory services are fully integrated within the WBG’s country financing and policy dialogue in the energy sector.”
[6] Rethinking Power Sector Reform in the Developing World, ESMAP Background Paper, September 2019.

Tuesday, January 7, 2020


Transport is one of the main sources of CO2 emissions and it is sometimes assumed that more buses and trains are the solution. Public transport has a collective value in its own right, but public transport per se is not always the silver bullet for huge reduction in CO2 emissions. Emissions per passenger-kilometre is an imperfect metric, but we have to accept that trains and buses do not always score well. They can, with too few passengers, have rather high emissions per passenger-kilometre, even compared to private cars. Policies to reduce total transport emissions can only be developed, therefore, if full account is taken of the multiple factors in play. Public transport will have a major role but our approach needs to be holistic, and integrated with other objectives as well as climate priorities.

It’s also the case that the economics answer to most problems – reflect the issue properly in prices and all will be well – does not always fit well with transport. Fuel is already highly taxed but much travel demand is essential and price-inelastic; higher fuel prices may have limited, or insufficient, impact on the demand for private vehicle use. This implies the need to look at wider policy options. These include the unglamorous world of other regulatory and planning interventions, including congestion pricing, traffic management and town and land use planning.

How does public transport score on emissions?

It is difficult to find statistics that are reliable, up-to-date, and truly representative, but it is not hard to find reasonable if approximate indications. The comparative (average) figure for the private car[1] is 171g per person-kilometre, falling to 85g for a driver and passenger, and 44g for a driver and three passengers. For buses the numbers likewise depend on fuel used, size and age of bus, type of journey and so on. My indicative estimates[2] for buses are DEFRA based and from the website . The figure for bus performance is an average CO2 emission of 822 g / km. The DEFRA statistics allowed Carbon to estimate the average loading of UK buses at 9.2 passengers.

In very approximate terms this means that the bus must have at least nine passengers in order to get down to 90g per person-kilometre and be able to “compete” on emissions with the private car with one passenger. Comparable results have been quoted by the US Department of Energy. Seat occupancy rates in cities may generally meet this challenge, but in many suburban or rural areas this is much less likely to be the case. That is certainly suggested by the estimates cited in Carbon, with much higher g/km figures cited for the average of bus journeys outside London. So for some journeys the bus will be generating lower emissions than the private car, but on lightly loaded routes, often those serving more remote areas, significantly more. Prima facie this is a disappointing finding for anyone expecting a simple solution to transport emissions.

A contrasting benchmark is the London Underground, with emissions estimated at a mere 9g per person-kilometre (and reduced further as the power sector moves towards complete decarbonisation); this offers an excellent example of public transport providing very clear emissions savings. A key factor is clearly utilisation or load factor, which in turn tends to reflect population density.

Of course the public transport network is about more than just passenger-kilometre comparisons. It is often an essential for other social and economic reasons – such as inclusivity, enabling economic activity, and reducing congestion. And for the personal choice of the environmentally aware, it will be preferable to choose public transport when it is available and meets the need, since the incremental emissions will be close to zero.

What mix of policies do we need?

The answer in the long run has to include low or zero carbon fuel sources. Electric vehicles (or equivalent alternatives such as hydrogen) have the potential, ultimately, to reduce emissions to close to zero. But while technology may be the primary means to achieving the ultimate goal of zero emissions, there should also be a big premium on the large, valuable and immediate gains to be made simply by reducing emissions from the stock of vehicles in use now and in the near and medium term. If more public transport per se is not a solution for the mitigation transport emissions then it’s worth examining other options. This blog has consistently emphasised the high value of immediate[3] emissions reduction as both postponing climate milestones and providing option value for the future. Immediate and urgent actions have a higher value, tonne for tonne, than future solutions.

Two factors that are a major contributor to energy consumption are speed and congestion, for obvious reasons. Speed matters because the energy requirement tends to rise as the square of velocity, as anyone who has used a trip computer to make this comparison on the motorway will testify. Congestion matters because of the loss of energy implied in constant stopping, starting, and idling.

The remedies are relatively straightforward to describe, at least in principle, although more complex to implement. Reducing and/or more strictly enforcing motorway speed limits could have a significant and immediate impact, with an additional benefit in terms of safety. Congestion pricing, applied successfully in London and elsewhere, could be used more widely in the UK and other major cities. Both these measures continue to have their merits even in an all-electric low carbon world, and are complementary to effective planning and good public transport systems.

The search for better and low carbon transport policies will continue, but it needs to be a mix of low or zero carbon sources of energy, clever urban planning, and economic incentives to reduce congestion, as well as well-designed public transport systems.

[1] BEIS figures as quoted by the BBC and shown in my previous posting of 2nd January 2020 on this subject.
[2] The author quotes estimates from different sources for out of London and in London buses, while aggregate figures are drawn primarily from a 2007 DEFRA study. Given the changes in bus fleets, and inclusion of some gas powered or hybrid vehicles, these are arguably dated estimates. However more recent 2015 figures released for the actual performance of new Routemaster buses on London routes show significantly higher fuel consumption and hence emissions than the indicative numbers I have used.

Thursday, January 2, 2020


Are they significantly worse than aviation? In any case the same policy issues, of failure to price or tax CO2 emissions, are relevant.

My last posting addressed one of the issues arising from the failure to price any of the carbon/climate externality of aviation into the cost/price of aviation fuel. Among other things this has, in the absence of low carbon aircraft alternatives, encouraged a possibly unsustainable expansion of demand for travel, and distorted the choices that travellers make between different modes of transport. In that posting I compared the emissions impact of flying and driving for a hypothetical choice of holidays travelling 2000 km on a round trip to the South of France; the key measure was grams of CO2 per passenger-kilometre.

But the issue is not confined to aviation. The same problems arise for shipping. Greenhouse gas emissions from all forms of international transport contribute to anthropogenic global warming, but were never covered under the Kyoto Protocol and continue to escape effective action, in the form of a carbon tax or a carbon price, to limit emissions and mitigate climate impacts.

So it seems fair, in this context, to consider the impact of another alternative type of holiday. More recently there has been much criticism of the negative environmental impact of cruise ships. This is by no means confined to emissions, and includes the overcrowding impact of very large cruise ships on major tourist destinations, such as Dubrovnik or Venice. Ships also tend to use heavy fuel oil which is particularly bad in terms of its immediate local consequences on air quality.

But the most serious issue for shipping is CO2 emissions, and, in terms of comparison with other choices for personal travel, some attention has been given to measuring these. Most published information on emissions statistics comes from the cruise companies, and it is not always easy to draw exact comparisons with other modes of transport.  Among other factors emissions per passenger-kilometre may be a rather poor metric since so much depends on the length and nature of the journey and the consumption of fuel for powering on-board services (lighting, catering, etc). And cruises will tend intrinsically to cover shorter travel distances, so some holidays based on short haul cruises will lead to lower emissions than some long-haul flights.

The BEIS has also put a figure on ferry transport - 18g of CO2 per passenger kilometre for a foot passenger, which is less than a coach, or 128g for a driver and car, which is close to our earlier figures for a long-haul flight. But ferries ages and efficiency will vary around the world - and a ferry won't get you to the Caribbean, although a cruise ship or ocean liner would.

A 2010 paper[1] in Energy Policy presented the results of research into international cruise ship journeys to and from New Zealand. CO2 emissions from such journeys were calculated using an activity based, or “bottom-up”, model. The estimates for individual journeys by cruise ships to or from New Zealand in 2007 ranged between 250 and 2200 g of CO2 per passenger-kilometre (g CO2 per p-km), with a weighted mean of 390 g CO2 per p-km.
Carnival Corporation and plc, which owns nine cruise lines, claims its 104 ships emit an average of 251g of carbon dioxide equivalent per "available lower berth" per kilometre. Given improvements since 2010, this seems consistent with the earlier study which had argued that values similar to those of economy-class air travel could be obtained. 

The Energy Policy paper also calculated price elasticities and international cruise journeys for transport purposes were found to have a greater relative decrease in demand than plane journeys if the impact of carbon pricing was analysed. In other words, putting a price on the environmental damage would be even more effective in reducing emissions from cruise ships, reducing demand for cruises as a preferred holiday option and incentivising cruise companies to develop cleaner solutions.
There is often a “shore-side” perversity as well. The absence of any penalty on burning heavy fuel oil means that ships will also continue to pollute the local environment in port when it would be a straightforward matter to power on-board facilities through connection to the local electricity network, which will often be based on a cleaner fuel mix.
Once again the transport and travel sectors provide a textbook illustration of the need to reflect clear externalities into the pricing of travel, so that consumers can make choices that come closer to reflecting a balance of personal benefits and societal damage. The evidence is that this can work both by shifting demand to less “carbon-intensive” activity , and by reducing the environmental impact of supply.

[1] Carbon emissions from international cruise ship passengers' travel to and from New Zealand. Howitt et al. Energy Policy. Volume 38, Issue 5, (May 2010)