The start of 2016 saw London breaking annual pollution limits across a number of destinations within days of the new year; a situation that has happened a number of years in a row.
Putney High Street is one such location, breaking its limit of 40 micrograms of nitrogen dioxide for the 19th time, at 7am on Friday 8th January 1 . The limit for the year is 18. Other cities in the rest of the world are coming under similar scrutiny, with Beijing regularly held up as an example of what happens when fossil fuel usage impacts an urban environment. Images from September 3rd 2015 – China’s World War II ‘Victory Day’ parade – showcased this perfectly: factories had been closed for days beforehand and half of all cars banned from using roads from August 20th 2 . Beijing landmarks had rare backdrops of blue skies for two weeks, which were immediately lost come the 4th of September, replaced by smog as factories and cars returned to normal working conditions.
When images like this capture the public imagination, it is very easy to see why so many believe that urban centres are behind climate change. What’s more, this is backed up by the data. The Intergovernmental Panel on Climate Change (IPCC) released its fifth assessment report on climate change in 2014, identifying that between 67 and 76 per cent of global energy consumption takes place in urban areas, consumption that accounts for around 75 per cent of greenhouse gas (GHG) emissions 3 . While such reports are overviews of analysis undertaken by Working Groups within the IPCC, those Working Groups study primary scientific literature to reach their conclusions. There are dissenting voices to this view, however, citing the huge supply chains that are necessary to keep cities up and running and how these supply chains cross both rural and urban areas 4 .
How should the GHG emissions caused by activities that cross rural and urban boundaries – aviation, commuting, agriculture – be attributed?
This is a key question for many as it directly impacts how responsibilities for GHG emissions (and their reduction or mitigation) are assigned geographically; either with towns, regions, countries or continents. When a UK citizen buys a television made in China, are the emissions incurred in that production the responsibility of the buyer or the manufacturer? Whether responsibility is assigned to production or consumption can drastically alter how much impact cities can be said to have on overall GHG.
While this debate is crucial in many circles, especially post-COP21 as governments get to grips with the targets they have set themselves for emissions mitigation and reduction, such finer details don’t trump the universal truth that more people will naturally create greater energy demands. The world population is set to reach 9.7 billion by 2050, up from 7.3 billion today 5 . On top of this the proportion of that population living in urban areas is set to increase from 54 per cent today to 66 per cent in 2050 6 . So on whichever side of the production/consumption fence one sits, urban areas are going to grow and therefore their emissions will grow too.
As they hold the majority of the world’s population, solutions to reduce emissions from cities will be key to tackling climate change, something that, as an organisation, the National Physical Laboratory (NPL) is helping to do through the Decarbonathon. A competition designed to uncover innovative, green solutions to emissions-heavy activities, NPL, along with ENGIE, the World Economic Forum’s Young Global Leaders and Climate-KIC, is working to bring technology to cities that will make them cleaner environments.
To achieve this, it makes sense to identify the biggest emitters of GHG in cities. Data, again from the IPCC, gives good indicators, on a global level, of what the main polluting activities are 7 . Industrial activity is the number one culprit, responsible for 19 per cent of emissions. Transportation is second, accounting for 13 per cent.
Finally, energy consumption in residential and commercial buildings is responsible for eight per cent of GHG, but it is worth noting that this is on a global level. There are major variations between developed and developing countries, as well as between the West and East and Europe and the USA. Even in developing countries, typically with poorer inhabitants on the whole, there is a major divergence in emission footprints between rich and poor. While the data does indicate that modern urban lifestyles led by the wealthiest populations on the planet are responsible for the majority of GHG, significant differences can be seen within this demographic.
In Washington DC, for example, GHG emissions come in at 19.7 tonnes per capita. Compare this with London, on 6.2, and New York, on 7.1, and it is possible to see how city design and operation influence emissions. The large open spaces and buildings in Washington DC, coupled with extensive suburbs and a lack of widely used, quality public transport, is very different to the dense environments of London and New York, both with highly successful public transport networks. If such variation is possible between urban areas in similarly well-developed countries, then there is clearly a large amount of room for reducing urban emissions in cities in the west before we consider the need for drastic wholesale shifts in population behaviour.
In order to do this, it is necessary to become more granular with the measurements of GHG emissions by activities. The numbers cited in this article are on a global level. Given the wide range in emissions demonstrated between cities at a similar developmental, modern stage, it is reasonable to assume that such global figures are also subject to large variations depending on location. The models that are used to overcome this and derive emissions figures locally tend to use emission conversion factors that calculate the amount of GHG (e.g. carbon dioxide) attributed to the use of one kWh of electricity. In other words, it calculates the amount of greenhouse gas emitted based on activity performed.
These factors are established using direct measurements in situ, but there is a wide variation in the capability of direct measurement between countries and regions. Therefore, some countries do not have the means to make these measurements and hence rely on unsuitable data from elsewhere. Emissions from some sectors, for example electricity, are very country specific due to the different energy mixes; in agriculture uncertainties in emissions from livestock or fertiliser use can be greater than 50% 8 , again creating inaccuracies. In order to overcome such discrepancies and ensure that effective measuring of emissions from urban activities can take place, we need to deploy measurement methods of variable costs and sophistications so that all can use them.
A system on the more sophisticated end of the range is the Differential Absorption LIDAR 9 (DIAL), a mobile facility able to monitor atmospheric pollutants remotely at ranges of up to 3km. Concentration and spatial distribution of atmospheric pollutants can be determined directly, producing 3D concentration profiles in real-time situations where emissions need to be pinpointed and quantified. It measures upwind and downwind to differentiate between emissions which could be blown onto the site from other sources and covers a wide range of gases and volatile organic compounds, including: SO2, NO2, NO, ozone, for example, and higher aromatics such as alkanes, petroleum and diesel vapours, HCl and H2S.
A less sophisticated, and lower cost, option is a portable remote infrared imaging system. These are popular for leak detection within the gas industry as they can be used systematically to check individual valves and other common sources. Although they cannot quantify the volume of the leak, they can establish the main leaking components that can subsequently be fixed.
Other systems fill this gap by measuring the amount of emission present in the air, but do not pinpoint the source. Cavity Ring-Down Spectroscopy (CRDS) can be left in situ to provide continuous quantification of ambient emission concentrations with very high accuracy. The source of the leak can sometimes be inferred by combining these measurements with wind data and a site map in a model. CRDS instruments are usually fixed in their location, which means the strategic positioning of these systems needs to be appropriate.
The DIAL method can be used to plan and monitor this on a regular basis. Combining CRDS with infrared imaging systems can furthermore provide a cost-effective solution to accurately monitor emissions across sites and activities on a continued basis.
There is therefore a range of methods, at varying levels of costs and sophistication, that can be deployed to accurately assess GHG emissions. This level of precision leads to more accurate predictions of total GHG emissions as the conversion factors themselves are closer to the real thing. And with greater accuracy comes a greater knowledge of how activity in urban areas is responsible for GHG emissions.
Once the activities that are the root cause of urban emissions are precisely known, cities can then move on to implementing schemes that help these activities reduce the GHG byproducts. These schemes are necessary as there appear to be certain economic barriers to the large scale development and deployment of renewable technology, especially in the energy industries 10 :
1. Existing fossil and nuclear fuel industries are mature and highly interlinked with modern day power supplies, a situation with which new market entrants rarely have the ability to compete.
2. Subsidies often create unfair market conditions, especially as industries that generate GHG still receive more subsidies than clean technologies. The International Energy Agency measured the total amount of subsidies to both fossil fuel and clean energy industries in 2013 and it found that the former received four times more than the latter. 11
3. Gaining funding for technologies that may not pay back in the near future makes it harder to secure capital to develop innovative technology. For example, there has lately been a reluctance for venture capitalists (VCs) to invest in clean technology, typically an audience that can help convert research into commercial reality. Current VC investment stands at $4.8bn globally, far below the peak in 2008 of $12.3bn. 12
The Decarbonathon project is one such scheme that aims to mitigate the impact of such influences, organised by the National Physical Laboratory’s Centre for Carbon Measurement and ENGIE with support from the World Economic Forum’s Young Global Leaders and Climate-KIC. The winners of the Decarbonathon will receive industry support and access to investment to help them overcome such obstacles and bring cleaner air to our cities.
Bynd is one such innovator uncovered through the Decarbonathon, working to develop a car-pooling app that, unlike existing car-pooling services, is aimed at the regular commuter. According to the campaign for better transport, work-related travel accounts for 37 per cent of total passenger travel emissions and 91 per cent of car commutes are single passenger journeys. Bynd aims to work with companies to develop an app that allows staff within the same business (or another nearby) to combine journeys. This overcomes a big issue associated with carpooling services (different destinations) and reduces the number of car journeys taken in cities.
Another transport-focused technology seeking growth through the Decarbonathon is TEBS – the Traffic Energy Bar System. Taking a different approach to Bynd, TEBS is not attempting to shift existing behaviour to lower traffic on the roads, rather it makes use of that traffic to reduce energy usage elsewhere. TEBS is a system installed across high traffic areas, in which bars are pressed down by the wheels of the car as it moves over them, creating an up and down motion that generates electricity. It takes the velocity of the cars and maximises its usage; that velocity will not only transport people around, but also power other systems in the city that require electricity.
This helps reduce energy usage across the other two areas cited by the IPCC as being major emitters of GHG: industry and residential homes. Another innovation receiving help through the scheme that aims to reduce industrial and residential emissions is Mutum. Another idea borne out of the sharing economy, it aims to reduce overconsumption by making it easier to share things with others. Mutum uses a statistic they attribute to the Zerowaste campaign in France – that a typical electrical drill is only used for 12 minutes during its lifetime 13 – to showcase how objects can be lent rather than bought and then only used once or twice. Overconsumption creates wasteful industrial processes through over-manufacturing, so reducing these emissions will help lower urban energy demand and subsequent GHG emissions.
While each of these innovations may appear very early-stage, or small scale, the potential is large. Venture capital investment is low, but overall clean-tech investment is on the up. A number of studies have also shown that there is public appetite for such technology, with research in Finland 14 and the US 15 showing that the public care about use of renewable energy. With ground swell comes a change in perceptions and projects like the Decarbonathon will hopefully increase awareness of how urban centres can reduce their GHG footprints.
The issue of heavy GHG emissions in cities is already receiving widespread reporting in mainstream media, such as the health risks associated with diesel fumes 16 due to the Volkswagen emissions test rigging scandal 17 , so it can be expected that demand for a reduction of emissions will follow this increased awareness. In some cities this is already happening, with plans in London to introduce an Ultra Low Emissions Zone in 2020 18 .
It could be said, then, that the future is looking bright for the world’s urban areas. They may be growing, but we have the technology available to measure how this growth is impacting emissions. We also have the technology to help reduce those emissions. There are schemes and funding through which these technologies can be developed and deployed. Social perceptions of such technology are also shifting positively. And the political will has also been found, with the timely agreements at COP21. Everything is in place to deal with urban GHG emissions and with projects like the Decarbonathon, that goal can be achieved.
Published: 16th Feb 2016 in AWE International